By Casey Luskin, M.S. (Earth Sciences), J.D.
In its response to the chapter on biogeography in the supplementary textbook Explore Evolution: The Arguments For and Against Neo-Darwinism (EE), the National Center for Science Education (NCSE) asserts that EE "mangles the tiny fraction of biogeography covered."* If anything is mangled, it is the NCSE's response, which hops in a scattered fashion from issue to issue, repeatedly misrepresents the arguments of EE, and relies on double standards in order to nitpick over trivial matters. Additionally, the NCSE cherry picks data to make it appear that biogeography consistently supports universal common descent. The NCSE has adopted the shotgun approach to attacking EE, using any argument, however weak, that comes to hand.
What follows is a response to the NCSE's analysis. As we will observe, EE's treatment of biogeography is not only accurate but, contrary to what the NCSE claims, EE is similar in scope to treatments of biogeography found in comparable high school and college level biology textbooks. EE provides students with a sound introduction to the topic of biogeography while exposing them to multiple scientific viewpoints regarding neo-Darwinian orthodoxy. However, by presenting a diversity of scientific views on neo-Darwinism, EE commits an offense that the NCSE cannot tolerate. Thus, the NCSE repeatedly resorts to personal attacks on EE's authors, making liberal and flippant use of wholly irrelevant "creationist" labels. If anything, the NCSE's response underlines the accuracy of EE, and the lack of support from biogeography for any substantial creative power of the Darwinian mechanism.
I. NCSE Misstates, but then Unwittingly Validates, EE's Arguments on Island Biogeography
The NCSE misrepresents the arguments in EE by claiming that the textbook endorses the fixity of species, and that it denies any degree of evolutionary change can take place. Thus, while asserting that "rapid ecological and morphological diversification of organisms on islands shows how quickly evolution can produce novelty," the NCSE alleges that "Explore Evolution dances around this point." The NCSE further asserts, "Explore Evolution claims that some people who doubt common ancestry accept fixity of species, so biogeography doesn't prove anything to them."
The NCSE has grossly misstated and overstated EE's argument. The truth is that EE nowhere endorses the "fixity of species," and unambiguously acknowledges that the biogeographic evidence shows that some degree of biological adaptation can indeed evolve among isolated island species. As EE states at the beginning of its "Reply" section of the biogeography chapter:
You may be surprised to learn that most critics of neo-Darwinism agree with many of the arguments you have just read [from proponents of neo-Darwinism]. At least, up to a point. Few biologists today would argue over whether the different species of Galápagos mockingbirds (for example) descended from a common ancestor. (EE, pg. 79)
Rather than "dancing" around anything, EE makes it clear that critics of neo-Darwinism do not dispute that the biogeographical evidence shows some degree of real evolutionary change.
The NCSE further misrepresents EE by claiming that EE sets up a straw man of neo-Darwinism by asserting that island biogeographical evidence "does not allow 'unlimited change,' without showing that anyone thinks such change exists or needs to exist." However when EE uses the phrase "unlimited change," it is not setting up a straw man characterization of neo-Darwinism. It is simply recounting the doubts of the famous 19th century naturalist Georges Cuvier. Thus, the NCSE is taking EE's words somewhat out of context, and failing to note that EE's modern argument is much more precise. EE actually states:
If Universal Common Descent is true, it must have a mechanism that can produce macroevolutionary change--that can transform one type of animal into a fundamentally different type of animal ... Since critics of the argument from biogeography see no evidence of large-scale change, or of a mechanism that can produce the new genes needed to cause such change, they doubt that the biogeographical distribution of animals supports Universal Common Descent. (EE, pg. 77, emphasis added)
While the NCSE in some places distorts EE's actual argument, its rebuttal elsewhere makes it clear that it does understand--and implicitly concedes the validity of--EE's actual characterization of neo-Darwinian arguments. At one point the NCSE summarize EE's argument as saying "Organisms that have diversified on islands show only limited change, not 'fundamentally different' forms." (emphasis added) Elsewhere, the NCSE adopts EE's terminology and standard of evidential proof,1 alleging that "[t]he adaptive radiations of honeycreepers in Hawaii (and many other groups) represent a range of variation that meets any fair definition of 'fundamentally different.'" (emphasis added) Thus, the NCSE apparently understands EE's actual position that neo-Darwinism requires not "unlimited change," but does require that organisms may be transformed into into forms that are "fundamentally different."
It is here that the NCSE not only fails to meet the required standard of evidential proof, but in response tries to use examples discussed by EE, thereby unwittingly validating EE's arguments as strong, non-straw man critiques of the actual arguments used by neo-Darwinists. Thus, the NCSE argues:
The adaptive radiations of marsupials in Australia, finches in the Galápagos, honeycreepers in Hawaii, or cichlids in Africa's Rift Valley (to choose but a few examples) produced a range of variation equivalent to variation seen within vastly larger taxonomic groups. While the variation is not infinite, saying that these species are not fundamentally different from their ancestors ignores the basic biology.
Marsupials will be covered in Part II of this response, but for now let's assess some of the NCSE's other examples of biogeography that allegedly show the ability of neo-Darwinism to produce "fundamentally different" organisms.
The NCSE complains that EE's "biological examples used are all instances of adaptive radiations on islands, an interesting topic, but not representative of the whole field." This is an odd claim since EE discusses marsupials which have a worldwide distribution and are not an example of an island group. Indeed, not only are EE's examples (marsupials, Galápagos birds, and Hawaiian fruit flies) commonly found in mainstream biology textbooks, but nearly all of the NCSE's examples of biogeography allegedly supporting neo-Darwinian evolution are adaptive radiations on islands. If the NCSE protests that EE discusses too many island examples of adaptive radiation, then its response is subject to the same spurious criticism.
A. Hawaiian Fruit Flies
While the NCSE alleges that EE fails to discuss biogeographical examples that demonstrate the creative power of the neo-Darwinian mechanism, one of the examples the NCSE gives in support of such creative power is the diversity of fruit flies in the Hawaiian Islands. But far from ignoring Hawaiian fruit flies, EE addresses this topic in its chapter on biogeography, observing that proponents of neo-Darwinism cite Hawaiian fruit flies as biogeographical evidence supporting evolution:
Contemporary evolutionary biologists point to other biogeographical evidence in support of this view. For example, in the Hawaiian Islands, there are hundreds of species of the fruit fly genus Drosophila. These species are not found anywhere else in the world. Why are there so many different species of fruit fly in such a remote place? As the National Academy of Sciences argues, "The biological explanation for the multiplicity of related species in remote localities is that such great diversity is a consequence of their evolution from a few common ancestors that colonized an isolated environment." (EE, pg. 75)
The NCSE's arguments actually sound quite similar, stating: "at least a thousand species of flies -- many still waiting to be described -- in the genus Drosophila" exist in the Hawaiian Islands, species which are "seen nowhere else." By citing the unique species diversity among Hawaiian fruit flies as biogeographical evidence for evolution, the NCSE again unwittingly validates EE's discussion of how evolutionary biologists address this topic.
The NCSE's arguments on Hawaiian fruit flies are also subject to the same criticisms made by EE, which observes that the variations between the species are not large-scale:
critics note that the examples of mockingbirds in the Galápagos and fruit flies in the Hawaiian Islands show only small-scale variations in existing traits. Further, some geneticists think that these changes have occurred because the populations of these birds and fruit flies became isolated, and lost genetic information over time. (EE, pg. 77)
The NCSE claims that Hawaiian fruit flies "exhibit anatomical traits and behaviors seen nowhere else" but the NCSE's response gives no specific examples detailing exactly what these traits are or why these traits comprise a "fundamentally different" type of organism. Indeed, if as the NCSE states, these flies are all "in the genus Drosophila" then under conventional standards of taxonomic classification, they would not comprise "fundamentally different" forms. Since the NCSE offers not a single specific example of morphological novelty among Hawaiian fruit flies to prove its case, it's difficult to see why any Hawaiian fruit fly forms should be considered "fundamentally different."
In actuality, the NCSE is wrong: Hawaiian drosophilids, in their estimated 25-30+ million years of evolution,2 now span two genera, not one--Drosophila and Scaptomyza.3 As one review recounted, "[o]n the basis of a comparative study of the internal anatomy, Throckmorton (1966) observed that although the Hawaiian species could be divided into two main groups, they showed distinct similarities,"4 further noting that in some cases, the differences between the two genera "disappear."5 Thus, even after a few tens of millions of years of evolution,6 at most Hawaiian fruit flies have only evolved sufficiently to warrant the creation of one highly similar new genus. To give an idea of just how similar these two genera are, an authoritative review by Hackman states that "[t]he external morphological characters generally used for separating [Scaptomyza from Drosophila]"7 include:
slightly different head dimensions and eye shapes 1 fork (Scaptomyza) vs. 2+ forks (Drosophila) on antennae bristles, known as arista dull (Scaptomyza) vs. shiny (Drosophila) plates covering the middle of the thorax 2-4 (Scaptomyza) vs. 6-8 (Drosophila) acrostichal rows of hairs differences in the shape of the male anatomy and some other internal anatomy, such as the spermathecae, testes, vasa deferentia, paragonia, ejaculatory apodemes, and Malphigian tubules short (Scaptomyza) vs. long (Drosophila) egg filaments
If this short list presents an underwhelming degree of morphological change over tens of millions of years of evolution between these two groups, consider that the two genera are so similar that for some species, it's been difficult to determine where exactly they belong.8
Even here, however, the biogeographical evidence is not clear that the two genera evolved from a common ancestor in the Hawaiian Islands. Authorities have recognized the possibility that "Scaptomyza was introduced into Hawaii independently of the other Hawaiian drosophilids" and "can be descendants of the second migration of drosophilids into Hawaii."9 Given that Scaptomyza-like fossils are found in the Dominican Republic as early as 23 Mya,10 some evidence suggests that Scaptomyza may not have evolved or originated in Hawaii from the genus Drosophila. As is often the case, opinions differ: A recent paper in Biology Letters observes that "[t]he possibility that some lineages [of Scaptomyza] may have originated in Hawaii and subsequently 'escaped' to diversify on continental landmasses is expected to be rarer still," yet such a rare and improbable migration of fruit flies away from Hawaii to colonize much of the rest of the world is exactly what this study then suggests.11 Another study observed the possibility that the two lineages result from "two independent introductions from continental ancestors."12 The worldwide distribution of Scaptomyza fruit flies similar to those in Hawaii has thus been called a "mystery,"13 and this does not present a clear-cut case of island biogeographical evidence for evolution.
Those debates aside, the differences between Hawaiian fruit fly species are often quite trivial. A National Academy of Sciences booklet advocating evolution admits that "evolutionary biologists have focused their attention on a group of about 100 drosophilid species that have characteristic light and dark markings on their large wings."14 But changes in wing coloration markings obviously do not comprise the evolution of a "fundamentally different" or "fundamentally new" form.
If these flies still all qualify as drosophilids within the same family, and at most fit within a couple of highly similar genera, how can the NCSE argue that this example shows the evolution of "fundamentally different" forms? As EE rightly notes, all of the changes in Hawaiian fruit flies could result from small-scale variation in pre-existing traits.
B. Galápagos Mockingbirds and Galápagos Finches
The NCSE complains that EE discusses the Galápagos mockingbirds rather than the Galápagos finches in EE's chapter on biogeography. In fact, EE does discuss the Galápagos finches extensively in its chapters covering natural selection and mutations. But the Galápagos mockingbirds too have been important to the study of evolution and biogeography, so it is not inappropriate for EE to cite them in its chapter on biogeography. The British Natural History Museum's website observes that the Galápagos mockingbirds played an extremely important role in the development of evolutionary thinking:
Mockingbirds from the Galapagos Islands, not finches, gave Charles Darwin his ideas about evolution. ... Darwin's finches are the better-known birds connected with helping Darwin come to his conclusions on evolution. However, it was the little-known mockingbirds that were the key.15
Indeed, historian of science Frank Sulloway observes that "far from being crucial to his evolutionary argument, as the legend would have us believe, the finches were not even mentioned by Darwin in the Origin of Species."16 Clearly, EE's discussion of Galápagos mockingbirds does not necessarily ignore any important biogeographic argument for evolution. Given that other mainline biology textbooks, such as Belk and Maier's 2010 edition of Biology: Science for Life, discuss the Galápagos mockingbirds (and do not discuss the finches) in their treatment of biogeography17 it seems that the NCSE's complaint that EE does the same entails nitpicking.
The reality is that whether we look at Galápagos finches or mockingbirds, neither group shows evidence for large-scale evolutionary changes, and their diversity is even more limited than that of Hawaiian fruit flies. Thus, EE observes about the GalÃ¡pagan mockingbirds:
[M]ost modern critics of neo-Darwinism accept the idea that all the mockingbirds of the Galápagos have a common ancestor. In their view, the evidence does support the idea that these birds have changed in response to their environment (Evolution #1), but it does not show that all creatures everywhere have a single common ancestor (Evolution #2). And that's the rub. These scientists accept that plants and animals of the Galápagos were transported or migrated to the islands and then adapted in some ways to their new environment. They point out, however, that migration and adaptation does not equal macroevolutionary change. (EE, pg. 76)
It's difficult to argue for macroevolutionary change observed among the Galápagos mockingbirds or finches. Regarding Galápagos mockingbirds, Whittaker's textbook Island Biogeography observes that it is "unclear whether their genus (Nesomimus) is sufficiently distinct morphologically to warrant separation from the mainland genus (Mimus)," further stating that "Similar problems exist with the finches."18 As EE puts it, the mockingbirds "show only small-scale variations in existing traits." (EE, pg. 77)
The NCSE's response is to cite the Galápagos finches and claim that their different beaks and differing modes of feeding really do show the evolution of "fundamental differences." A reality check is necessary: the finch species represent highly similar birds which, according to a paper in BioScience, "retain the ability to interbreed and produce viable, fertile hybrids."19 EE too rightly notes that several Galápagos finch "species" are known to interbreed in the wild.20 Even some authorities in evolutionary biogeography take a ho-hum attitude about the degree of biodiversity represented by Galápagos finches (or Hawaiian fruit flies). Geerat J. Vermeij writes in Frontiers of Biogeography:
Hawaiian drosophilid fruit flies ... [and] GalÃ¡pagan groundfinches ... are in reality modest in terms of species numbers and net rates of species formation.21
Adopting an unimpressed tone, Vermeij continues, "The dozen or so groundfinch species (Geospiza) of the Galápagos are the net product of at least 14 million years of evolution..."22
In its response to EE, the NCSE asserts "the range in sizes" among GalÃ¡pagan finch species is "vast," but this is a gross misrepresentation of the data. The reality is that GalÃ¡pagan finch species range from 4 -- 8 inches (10 -- 20 cm) in size.23 Thus, in his Pulitzer Prize winning book The Beak of the Finch, Jonathan Weiner compares the largest and smallest Galápagos ground finch species and remarks that, "The largest fortis on Isabela are, even to Peter and Rosemary Grant, 'almost indistinguishable' from the smallest of the magnirostris on RÃ¡bida."24 Weiner continues, "You can't distinguish these three species by their plumage, and usually not by their build or body size either."25 Likewise, Whittaker's treatise observes that "it is extremely difficult to identify all the [Galápagos] finches, as the largest members of some species are almost indistinguishable from the smallest members of others."26
The finches have evolved different beak forms and feeding habits, but if "almost indistinguishable" species that are still capable of interbreeding and span a narrow size range of 10-20 cm represents a "vast" difference, then the NCSE must have exceedingly low standards for what constitutes a "fundamentally different" type of organism.
C. More Island Bird Radiations -- Hawaiian Honeycreepers
The NCSE claims that Hawaiian honeycreepers "show a range of variation in morphology and ecology which falsifies any claim that evolution on islands does not produce fundamental differences." But these birds are very much like the case of the Galápagos finches27: According to Brown and Limolino's text Biogeography, these species differ "conspicuously in the sizes and shapes of their beaks and to a lesser extent in color pattern"28--clearly not fundamental differences.
Indeed, Cox and Moore's Biogeography: An Ecological and Evolutionary Approach states that the ancestor of Hawaiian honeycreepers "was probably a finch-like immigrant from Asia which fed on insects and nectar" and that "[m]any of the genera ... are still nectar feeders."29 They argue that it is merely a "short step" from this ancestor to evolve some of the key diversity in feeding behaviors found among the honeycreepers:
Since insects, too, are attracted to the nectar, it is not surprising to find that many nectar eaters are also insect eaters, and from this it is a short step to a diet of nothing but insects.30
It should come as little surprise, therefore, that of the 11 genera of Hawaiian honeycreepers, the vast majority continue to feed on insects and/or nectar, with only a few species now feeding only on fruits and seeds.31 Indeed, despite the variation in beaks and plumage, the various species of honeycreepers are highly similar genetically. A study by Tarr and Fleischer concluded that, "genetic differentiation between species is less than would be expected on the basis of morphological divergence."32
Taking these types of facts into account, William Dembski and biologist Jonathan Wells provide a lucid discussion of the actual degree of biodiversity represented by honeycreepers:
[T]hroughout such changes, the basic body type and structural features of the honeycreepers were preserved. In other words, there was diversification, but only within limited boundaries. Different forms of Hawaiian honeycreepers are (as far as we know) reproductively isolated from each other -- and are thus separate species according to the Biological Species Concept. Nevertheless, they differ from each other no more than, say, different breeds of dogs, which are all members of the same species. In fact, the morphological differences between some dog breeds are greater than the morphological differences between species of Hawaiian honeycreepers.33
At most, the biogeographical evidence from examples like Galápagos finches or Hawaiian honeycreepers shows that finch-like birds on isolated islands can evolve modestly different beak shapes to exploit new food sources such as insects, seeds or nectar (common food sources for birds), as well as modest changes in coloration patterns.34 But that's about it. As Dembski and Wells rightly observe, "the basic body type and structural features of the honeycreepers were preserved." Hawaiian honeycreepers do not entail the evolution of "fundamentally different" organisms. Rather, it would be far more accurate to say that they are fundamentally the same.
D. African Cichlids
The only non-island adaptive radiation discussed in any meaningful depth by the NCSE that is not found in EE is cichlid fishes--an example often left out of biology textbooks.35 The NCSE boasts that "nearly 1000 species of cichlid in Lake Malawi evolved in the last few million years." A closer look at cichlids shows that the differences that constitute separate "species" among cichlids can be quite trivial.
For example, the cichlid genus Labeotropheus has 2 species, L. fuelleborni and L. trewavasae, which are morphologically almost identical.36 Yet they are considered to be different species largely because the more territorial L. fuelleborni is generally found in the upper 8 m of lakewater, while L. trewavasae wanders more during feeding and can be found as deep as 20 m.37 Under natural conditions in the lake the two populations are not observed to interbreed, largely because they generally traverse different depths, and thus technically meet the definition of the biological species concept. Thus they are considered separate "species" despite their extreme morphological similarity.
One textbook discusses a similar study that found only "small degrees of ecological separation" among cichlid species, where the differences between species entailed "feeding preferences" which merely "put species in different places" in the lake.38 Like the cases of island bird radiations discussed above, cichlid species exhibit a variety of different feeding mechanisms and behaviors, but at the end of the day, are all distinctly classified within cichlid fishes, and are not "fundamentally different" organisms.
The NCSE can cite cichlid fishes, but this example too is subject to the same criticisms that EE makes against other examples of adaptive radiations: "The evidence is just as consistent with a polyphyletic view (the orchard picture of the history of life, in which only minor variation has taken place) as it is with the monophyletic view (the single tree picture of the history of life, in which macroevolutionary change has taken place)." (EE, pg. 76)
II. EE and Marsupials: Where's the Problem?
The NCSE's response to EE on marsupials adopts another misguided two-pronged strategy that seems intent merely upon finding flaws and making noise, even if no actual errors exist in EE.
First, the NCSE misrepresents the text of EE, wrongly claiming that there is a "total omission" of important aspects of marsupial biogeography like migration.
Second, the NCSE waxes eloquent about marsupial history (wrongly implying that experts monolithically agree on all the details), as if somehow this history refutes or challenges the text of EE. If anything, the NCSE's description of marsupial biogeography and history is highly congruent with the treatment in EE, and validates EE's arguments.
A. The NCSE Misrepresents EE's Discussion of Marsupial Biogeography
The NCSE states regarding EE's discussion of marsupials that "The total omission of plate tectonics from this discussion is inexcusable." Did the NCSE even read EE? The textbook has a discussion of plate tectonics and marsupials that's difficult to miss:
Why are marsupials mainly found on those two continents? Proponents of Common Descent offer this explanation. The first mammals with the marsupial's distinctive mode of reproduction arose on the ancient southern super-continent of Gondwanaland. Later, after this great land mass broke up into separate continents, the ancestors of the modern marsupials were separated from other mammals and evolved in isolation on the new continents of Australia and South America. The distinctive Australian marsupials--kangaroos and koalas, for example--are the result of that evolutionary process in an isolated locale. (EE, pg. 75)
Likewise, the NCSE states that "Extinction, migration and diversification are important parts of biogeography and evolution, and Explore Evolution does students a disservice by ignoring or misrepresenting these processes." Elsewhere, the NCSE charges that migration is "ignored when convenient" in EE. These are bizarre accusations, and the NCSE seems overeager to find errors in EE whether they exist in the textbook or not.
Obviously EE mentions diversification in the context of its discussion of marsupials and Hawaiian fruit flies as quoted above, but EE makes it very clear that migration and plate tectonics have played a major role in marsupial history, concluding that even critics of neo-Darwinism acknowledge that "the worldwide distribution of marsupials provides evidence for only two things: continental drift and migration." (EE, pg. 78) Far from ignoring migration, EE discusses of the importance of this topic in relation to explaining radiations of species in the Galápagos Islands (see EE, pgs. 74-76). As regards extinction, EE makes much of this topic in multiple places when discussing the history of life (see, for example, EE pgs. 17, 32, and 95). EE certainly does not ignore migration, extinction, diversification, or plate tectonics.
B. The NCSE Makes Much Noise, But Never Identifies Any Legitimate Problems in EE
The NCSE describes EE's discussion of marsupials as follows: "Claim: Marsupials do not lend credence to universal common descent since they are not restricted to Australia and South America; instead, they also live in North America, and the oldest marsupial fossil is found in China." Yet nothing the NCSE states in its long discussion of marsupial history contradicts the text of EE, though the NCSE's discussion itself has a few questionable claims.
The NCSE complains that EE observes that there are "critics who express surprise that 'paleontologists have unearthed the oldest marsupial fossil of all ... in China'." The NCSE seems to wish to diminish the importance of this Chinese fossil find, arguing that "[t]he location where marsupials originated is a subject of ongoing research," even claiming "the area where the oldest marsupial fossil was found was much nearer to North America in the late Cretaceous when marsupials were first evolving as a separate lineage." This latter claim is odd since China was not close to North America at any time during the Cretaceous.39 But in fact, this discovery did change the way many perceived marsupial history and would have come as a surprise to some.
Prior to the discovery of the oldest marsupial fossil in 2003, the earliest marsupial fossils known were from North and South America,40 but this much earlier fossil from China at 125 Mya "extends the record of marsupial relatives with skeletal remains by 50 million years."41 News reports about the fossil rightly observed that it could "rewrite the history of mammal evolution."42 Mirroring some of the comments in EE, the lead scientist who discovered the Chinese marsupial fossil observed that "It's an interesting paradox. If you look across the world, South America and Australia, you find the present-day marsupials in great abundance and diversity. But those are not the original points where they evolved."43 Obviously marsupials must have migrated to new locations, a point which corroborates EE's observation that, "the worldwide distribution of marsupials provides evidence for only two things: continental drift and migration." (EE, pg. 78)
The NCSE then discusses how North American marsupial opossums migrated there from South America when a land bridge formed between the two continents around 3 Mya. Again, none of this contradicts anything found in EE, so the NCSE resorts to personal attacks: "This helps explain the confusion of the apparently biogeographically illiterate authors of Explore Evolution about why 'marsupials such as the opossum live in the northern hemisphere.' It is because of migration..." The NCSE's continued charge that EE ignores migration is bizarre. EE never said nor suggested that the presence of opossums in North America was not due to migration, and as noted above EE states "the worldwide distribution of marsupials provides evidence for only two things: continental drift and migration." (EE, pg. 78)
EE's point about marsupials and North America is that their history and present distribution does not necessarily demonstrate a southern origin of marsupials. Not only are there North American marsupials today, but Cox and Moore wrote (about 10 years prior to the discovery of the earliest marsupial in China) that "[t]he earliest marsupials ... are known from the late Cretaceous of both North and South America."44 They note that "[t]he simplest explanation of the final pattern of distribution of the two groups is to assume that marsupials evolved somewhere in the South America--Antarctica--Australia chain of continents" and then "dispersed through all three of those continents and also northwards to North America."45 But now that there is evidence that marsupials may have arisen in Asia in the Northern Hemisphere, clearly the correct explanation is not so "simple."
The NCSE charges that "[d]espite the feigned confusion of Explore Evolution's authors, the fossil record gives a very clear picture of the biogeographic history of marsupials." Whether or not EE exhibits "feigned confusion" (as noted, EE is quite clear that migration and tectonic history can explain current marsupial distributions), the NCSE is trying to present marsupial history as if it is monolithically settled among all biogeographical authorities. This accords with the NCSE's usual strategy of downplaying scientific disagreement. In reality, there are important debates about marsupial origins.
Cox and Moore note that the history of marsupials and placental mammals present a "zoological puzzle," as the fossil record shows that both groups have been widespread throughout the entire world, but their disparate present-day distribution suggests that in some locations marsupials outcompeted placental mammals, but in other places placental mammals seem to have outcompeted marsupials:
In the Early Cenozoic of the Northern Hemisphere, as in the Late Cenozoic of South America, the arrival of placentals led to the elimination, or near-elimination, of the marsupials. Why, then, did Early Cenozoic placentals of Australia become extinct, leaving the monotremes and the marsupials as the only Late Cenozoic mammals of that continent?46
This point negates the NCSE's just-so story that marsupials no longer dominate South America because "South America drifted north again and connected with North America around 3 million years ago, [and then] the Great American Biotic Interchange had the same devastating effect that biotic interchanges had on other marsupial faunas." Perhaps that is true for South America, but it's clear that not all biotic interchanges have had a "devastating effect" on marsupials; the history of marsupials is not nearly as clear-cut and simplistic as the NCSE portrays it.
The NCSE also cites a recent paper in Paleobiology to claim that the biogeography of placental mammals closely approximates that of marsupials, but a closer look at the NCSE's citation unveils contradictory data regarding placental mammalian history:
Where did the modern lineages of placental mammals originate? Recent molecular data seemingly have overturned not only schemata of placental relationships based on morphological data, but also hypotheses about the time and place of origin of the modern lineages. The original hypothesis of Northern Hemisphere origin, based on the fossil record, has been replaced by a "Garden of Eden" hypothesis of origins on a southern continent, based on molecular phylogenies.47
After reviewing a long and complicated history of marsupial paleobiogeography, the NCSE claims that marsupial biogeography "is consistent with the fossil record of placental mammals, and with other lines of evidence." However all this paper really corroborates about placentals and marsupials is that both originated in the Northern hemisphere. Indeed, Cox and Moore lament that "[u]nfortunately our understanding of the pattens of distribution of these two groups is hampered by our incomplete knowledge of the timing of some crucial plate-tectonic events and of the composition of some early faunus,"48 as "[t]he fossil record, too, is exasperatingly silent on the mammal faunas of Australia before the Oligocene."49 Clearly there is still much to learn about marsupial biogeography.
The take-home point, however, is this: While the NCSE's detailed exposition of marsupial history should be commended, it's not at all clear how any of it contradicts or would refute the arguments in EE. Despite all its sound and fury, the NCSE identifies no actual error in EE regarding marsupial biogeography.
C. Opossums and the NCSE's False "Creationist Source Material" Gambit
The NCSE states that EE's discussion of marsupials "bear[s] striking similarities to a critique of biogeography by young earth creationist Kurt Wise," even going so far as to claim that EE used Wise's work as "creationist source materials" on marsupials. The NCSE must really be scraping for arguments as it again tries to make the "creationism gambit."50 The fact that EE and others may have independently arrived at some similar arguments regarding marsupial biogeography does not imply that EE is thereby relying upon "creationist source materials."
In fact, it does not seem likely that EE relied on Wise at all as a source as his arguments are different from those of EE. In the passage quoted by the NCSE, Wise states: "The fossil record seems to show a migration of marsupials from somewhere around the intersection of the Eurasian and African continents and then a survival in only the continents farthest from their point of origin (South America and Australia)." Wise wrote that in 1994, and thus had no knowledge that the oldest marsupial would come from China (a discovery reported in 2003). The NCSE claims that allegedly "Similar misunderstandings plague the discussion of the marsupial fossil record in Explore Evolution," but the quote the NCSE then provides from EE discusses the implications of the oldest marsupial coming from China, a fact that Wise was obviously unaware of. A Chinese origin of marsupials is one of the key points about marsupials in EE, so it's difficult to argue that EE was merely mimicking a much older source that had no knowledge of later findings. The NCSE has not made its case for conspiracy.
Regardless, the NCSE claims that both EE and Wise are inaccurate because North American opossums are not descended from Australian possums. Yet neither EE nor Wise claims otherwise. Indeed, Wise notes that North American opossums are "thought to have come from South America, not Australia." The NCSE is not reading EE very carefully, but it must not be reading EE's alleged "creationist source materials" very carefully either.
D. Marsupials and the Problem of Convergent Evolution
The NCSE states that "The convergent evolution of Australian mammals and placentals found in comparable habitats elsewhere shows the power of evolution to adapt species to similar conditions." The NCSE is absolutely correct that there is incredibly high convergence between a number of groups of marsupial and placental mammals, including marsupial and placental "moles," "mice," "cats," "dogs," "squirrels," "groundhogs," "rabbits," "hippos," and "wolves." But what are the implications of this extreme morphological convergence for common descent?
While the NCSE cites "convergent evolution" as a validation of neo-Darwinism, the reality is that the high degrees of "convergent evolution" between marsupial and placental mammals entail a breakdown in the methodology used to infer common descent. Typically, high similarity between two organisms is taken as evidence of inheritance from a common ancestor, or homology. In its chapter on Anatomical Homology, EE provides a lucid discussion of how extreme convergent evolution poses a challenge to the methodology by which neo-Darwinists infer common descent:
Convergence is a deeply intriguing mystery, given how complex some of the structures are. Some scientists are skeptical that an undirected process like natural selection and mutation would have stumbled upon the same complex structure many different times. Advocates of neo-Darwinism, on the other hand, think convergent structures simply show that natural selection can produce functional innovations more than once. For other scientists, the phenomenon of convergence raises doubts about how significant homology really is as evidence for Common Descent. Convergence, by definition, affirms that similar structures do not necessarily point to common ancestry. Even neo-Darwinists acknowledge this. But if similar features can point to having a common ancestor--and to not having a common ancestor--how much does "homology" really tell us about the history of life? (EE, pg. 48)
EE is not the only source to observe that convergent evolution poses problems for phylogenetic-tree construction methodologies. Simon Conway Morris observes that convergent evolution forces proponents of neo-Darwinism to ask: "do we trust our phylogeny and thereby define convergence (which everyone does), or do we trust our characters to be convergent (for whatever reason) and define our phylogeny?"51 Conway Morris further explains:
I have been particularly struck by the adjectives that accompany descriptions of evolutionary convergence. Words like "remarkable," "striking," "extraordinary," or even "astonishing" and "uncanny" are common place. It is well appreciated that seldom are the similarities precise, and this in itself is as concrete a piece of evidence for the reality of evolution as can be provided. Even so, the frequency of adjectival surprise associated with descriptions of convergence suggests there is almost a feeling of unease in these similarities. Indeed, I strongly suspect that some of these biologists sense the ghost of teleology looking over their shoulders.52
The NCSE claims that marsupial biogeography provides a strong piece of evidence supporting neo-Darwinian evolution and common descent. Yet ironically, marsupial (and placental) mammalian biogeography forces evolutionary biologists to deny homology among many highly similar structures found between marsupial and placental mammals, a problem which could be devastating for the methodology used to infer common ancestry.
When constructing evolutionary trees, evolutionary biologists initially assume that high functional biological similarity is evidence of common ancestry. One authority explains that such assumptions are ubiquitous, "The assumption of homology is implicit in comparison of character states; that is, all states of a character derive from the same ancestral state."53 But when high similarity is not evidence of inheritance from a common ancestor, as is the case for many similarities between marsupial and placental mammals, the "assumption of homology," which forms the bedrock for all evolutionary trees, breaks down. A recent treatise published by Harvard University Press laments how convergent (or independent) evolution, causes severe problems for evolutionary phylogenies:
Cladistics can run into difficulties in its application because not all character states are necessarily homologous. Certain resemblances are convergent--that is, the result of independent evolution. We cannot always detect these convergences immediately, and their presence may contradict other similarities, "true homologies" yet to be recognized. Thus, we are obliged to assume at first that, for each character, similar states are homologous, despite knowing that there may be convergence among them.54
The reality is that "since the assumption of homology implies common ancestry,"55 without this assumption methodology used to infer common descent collapses. Another authority notes that "the assumption of homology ... was necessary to deduce a pattern of relationships,"56 but what happens if that assumption is false? If highly similar structures don't necessarily indicate homology, this casts doubt upon the basic methods used by evolutionary biologists to construct phylogenetic trees. Far from confirming common ancestry, the extreme convergent similarities between marsupial and placental mammals pose fundamental challenges to the methods used to argue for common ancestry.
III. The NCSE Ignores "Biogeographic Conundrums"
In its response regarding marsupials, the NCSE admits that "If the [North American] opossum truly had roots in Australia, it would indeed be a biogeographic conundrum." Since North American opossums are not descended from Australian "possums," their high morphological similarity dictates to neo-Darwinian evolutionists that this must be another case of extreme convergent evolution that challenges the methodology by which neo-Darwinism infers homology and common descent.
But what if North American opossums were descended from Australian possums? Why does the NCSE observe that this would pose a "biogeographic conundrum?" The NCSE says this because there would be no route by which Australian possums could have migrated to North America. The NCSE's reasoning here is sound: they presume that if organisms in Locale B are descended from organisms in Locale A, then there must have been some migration route by which organisms could migrate from A to B. If there is no such route, then we're presented with, in the NCSE's own words, a "biogeographic conundrum." Using such reasoning, the NCSE then argues that marsupials and other groups have biogeographic histories that are congruent with the tectonic history of islands and continents, thus allegedly supporting common descent:
The same pattern of diversification and migration seen in marsupials can also be seen in other groups of plants and animals. That consistency between biogeographic and evolutionary patterns provides important evidence about the continuity of the processes driving the evolution and diversification of all life. This continuity is what would be expected of a pattern of common descent, and is not what would be expected with the creationist orchard scheme.
With marsupials, the NCSE claims that the "continuity" of geography and evolution predicts that there will always be some land bridge or migratory pathway which terrestrial organisms can follow. This was claimed to allegedly show "consistency between biogeographic and evolutionary patterns" that demonstrates "what would be expected of a pattern of common descent." Ignoring the NCSE's continued inappropriate usage of the "creationist" label, their claim is simply not true, for there are many examples of terrestrial organisms existing and appearing in locations where no land-based migratory route is apparent. The NCSE's approach is to cherrypick examples to support their arguments for universal common descent, but a large number of "biogeographic conundrums" that challenge neo-Darwinism could be discussed.
Traditional evolutionary explanations of biogeography fail when terrestrial (or freshwater) organisms appear on an island or continent but there is no standard migratory mechanism for them to have arrived there from some ancestral population. The NCSE boasts about the use of migration pathways or land bridges to explain the presence of marsupials or other plants and animals around the world. But what happens when organisms--even higher mammals--appear on isolated islands, and there appears no way for their purported ancestors to migrate there? At these points, evolutionary biogeographers appeal to a fallback position, a suite of mechanisms of "oceanic dispersal." As a review by De Quieroz (2005) stated:
A classic problem in biogeography is to explain why particular terrestrial and freshwater taxa have geographical distributions that are broken up by oceans. Why are southern beeches (Nothofagus spp.) found in Australia, New Zealand, New Guinea and southern South America? Why are there iguanas on the Fiji Islands, whereas all their close relatives are in the New World?57
According to De Quiroz, such examples require "oceanic dispersal over tectonic vicariance as an explanation for disjunct distributions in a wide variety of taxa, from frogs to beetles to baobab trees."58 But he recognizes a fundamental problem with overseas dispersal hypotheses: "cladistic biogeographers claimed that hypotheses of dispersal were not falsifiable because all patterns of relationships can be explained by some dispersal hypothesis."59 He further states that, "A main objection to dispersal hypotheses is that they are unfalsifiable and thus unscientific," continuing that, "this can be countered by noting that, if plausible vicariance hypotheses are falsified, then dispersal is supported by default."60 In other words, evolutionists assume that traditional land-based migration pathways (the type of evidence the NCSE claims supports common descent) were taken, but when they aren't an option, one can always fall back when necessary on to unfalsifiable ad hoc hypotheses of oceanic dispersal. After reviewing a number of "unexpected" biogeographic data that require oceanic dispersal, De Quiroz's review concludes: "these cases reinforce a general message of the great evolutionist [Darwin]: given enough time, many things that seem unlikely can happen."
Thus, neo-Darwinian evolutionists are forced to appeal to "unlikely" or "unexpected" transmigration of terrestrial organisms, in some cases requiring the crossing of oceans ("oceanic dispersal") to account for some biogeographical data. Such data challenges the simplistic picture of biogeography put forth by the NCSE that biogeography lends support to universal common descent through congruence between migration pathways and tectonic history. If anything, the "disjunct distributions in a wide variety of taxa" would tend to lend prima facie support for an orchard model of life's history suggested by EE; a single tree of life hypothesis can only be sustained through extremely unlikely ad hoc appeals to oceanic dispersal to save universal common descent from difficult biogeographical data. What follows are some notable examples of such data.
A. Sea Monkey Hypotheses
One of the most infamous examples of the very sort of "biogeographic conundrum" the NCSE fears is the origin of South American monkeys, called platyrrhines.61 Based upon molecular and morphological evidence, "New World" platyrrhine monkeys are thought to be descended from African "Old World" or catarrhine monkeys. The problem is that plate tectonic history shows that Africa and South America split off from one another between 100 and 120 Mya, and that South America was an isolated island continent at least from about 80 Mya until about 3.5 Mya.62 Molecular studies claim that the South American monkeys split from African monkeys perhaps around 35 Mya.63 Monkeys are thought to have first evolved in Africa, and so somehow proponents of neo-Darwinism must account for the subsequent appearance of monkeys in the Upper Oligocene in South America.64 As Walter Carl Hartwig puts it: "The platyrrhine origins issue incorporates several different questions. How did platyrrhines get to South America?"65
If the standard evolutionary story is true, and platyrrhines and catarrhines are both part of the same crown group radiation of monkeys, then how did platyrrhines come to be in South America if South America was then an isolated island continent and there was no land-based route for monkeys to migrate from Africa to South America? For those unfamiliar with the arguments that proponents of neo-Darwinian biogeography make when backed into a corner, the answer to these questions is almost too incredible to believe: they propose that monkeys floated on rafts across the Atlantic Ocean to colonize South America. And of course, we can't have just one seafaring monkey, or the monkey will quickly die leaving no offspring. Thus, at least two monkeys (or perhaps a single pregnant monkey) must have made the rafting voyage.
If this proposal seems a little farfetched, consider the quite serious endorsement of the rafting hypothesis given in a recent authoritative book, Primate Biogeography: Progress and Prospects (2006). The authors of the chapter "The Biogeography of Primate Evolution," John G. Fleagle and Christopher C. Gilbert, state the problem as follows:
The most biogeographically challenging aspect of platyrrhine evolution concerns the origin of the entire clade. South America was an island continent throughout most of the Tertiary, and most of the orders of mammals found in Paleocene through Miocene deposits are endemic families or orders almost exclusively restricted to that continent. Primates first appear in the Late Oligocene and become common only in the Early Miocene. Rodents also appear first in the Oligocene. Both groups are almost certainly immigrants from some other continent, and paleontologists have debated for much of this century how and where primates reached South America.66
Likewise, a Harper Collins textbook on human evolution states:
The origin of platyrrhine monkeys puzzled paleontologists for decades. ... When and how did the monkeys get to South America? Prior to about 1970, paleontologists invoked the concept of parallel evolution. ... It seemed so unlikely that monkeys from Africa could cross a water barrier like the Atlantic Ocean... Molecular evidence demonstrated that all monkeys shared a common ancestor prior to their separation. ... The "rafting hypothesis" argues that monkeys evolved from prosimians once and only once in Africa, and that it is a primitive monkey (parapithecid), and not a prosimian, that made the water-logged trip to South America. ... Other species colonizing South America must have arrived in similar ways over millions of years.67
As noted above, the high degree of molecular genetic similarity between platyrrhine and catarhine monkeys precludes the possibility that African and South American monkeys are similar simply because of convergent evolution. Yet as Fleagle and Gilbert state, similarities between monkeys across the oceans "raises a difficult biogeographical issue" because "South America is separated from Africa by a distance of at least 2600 km, making a phylogenetic and biogeographic link between the primate faunas of the two continents seem very unlikely."68 They argue that in light of "[t]he absence of any anthropoids from North America, combined with the considerable morphological evidence of a South American-African connection with the rodent and primate faunas" that therefore "the rafting hypothesis is the most likely scenario for the biogeographic origin of platyrrines."69
All kinds of arguments have gone back and forth about whether such a rafting journey is possible or plausible. Of course millions of years ago Africa and South America were slightly closer than they are today, but they were still very far apart at the time monkeys supposedly colonized South America. Fleagle and Gilbert argue that at best, the position of the continents in the early Tertiary still requires a "journey from Africa to South America anywhere from 8 to 15 days."70 This is called "plausible," but a macroview must be taken here: Is there any real biogeographical evidence that can falsify common ancestry? If the presence of higher mammalian fauna on isolated island continents with no simple way to arrive there does not falsify neo-Darwinian explanations of biogeography, what will?
Indeed, the rafting hypothesis has serious problems, for monkeys and rodents have high metabolisms and require large amounts of food and water:
The case of platyrrhines is more difficult to explain as anthropoid primates have higher metabolic rates and do not have the ability for prolonged periods of topor. A two-week rafting event across the Atlantic must have involved a floating island with an adequate food and water supply.71
Such "floating islands" are said to exist, but they admit that "the prevalence of over-water dispersal during primate evolution seems truly amazing for a mammalian order."72 They further admit that "[t]he reasons for the prevalence of rafting during the course of primate evolution remain to be explained."73
Needless to say, not all feel comfortable believing that seafaring monkeys on rafts are "plausible." As Hartwig puts it, "The overwhelming evidence for the late Cretaceous-Pliocene isolation of South America renders the mechanical aspect of platyrrhine dispersal virtually irresolvable,"74 for "any late Eocene origins model must invoke a transoceanic crossing mechanism that is implausible (rafting) or suspect (waif dispersal) at best."75
And there are deeper problems: monkeys apparently made the journey, but other smaller African primates such as lorises and galagos never colonized South America. If it was so easy for monkeys to raft across the proto-Atlantic ocean, why didn't these lower primates also make the voyage? The answer we're given by Fleagle and Gilbert is that rafting is "clearly a chance event, an example of 'sweepstakes' dispersal" as "[o]ne can only speculate that by a stroke of good luck anthropoids where able to 'win' the sweepstakes while lorises and galagos did not."76 As another authority wrote, "[t]he evidence strongly suggests the existence of a Palaeogene transoceanic sweepstakes route between Africa and South America, and presumably also a similar route between Africa and Madagascar" to explain such primate distributions.77
Apparently the NCSE was not quite accurate when claiming that "By comparing macroevolutionary patterns between different groups, we find that the same patterns repeat. This strongly suggests that the same forces drove the diversification of those different groups." The truth is that whenever oceanic "sweepstakes" dispersal is required, we find an exception to expected neo-Darwinian rules of biogeography. And as will be seen below, there are so many exceptions that one might reasonably question whether the inviolable neo-Darwinian rule of universal common ancestry is supported by biogeography.
B. Other Seafaring Species and Biogeographic Conundrums
When proponents of neo-Darwinism "speculate" about the "luck" and "chance" needed to explain this "amazing" phenomenon and "challenging" biegeographical data, it seems clear that they are lacking reasonable explanations. Yet rafting or other means of "oceanic dispersal" have been suggested to solve a number of other biogeographical conundrums that challenge neo-Darwinism, including:
Lizards reaching South America78 Large caviomorph rodents reaching South America79 Bees arriving in Madagascar80 Lemurs arriving in Madagascar81 The arrival of other mammals in Madagascar, including the Tenrecidae (hedgehoglike insectivorous mammals), aardvarks, the hippopotamus, and the Viverridae (cat-sized carnivorous mammals)82 Dispersal of salamanders across the western end of the Mediterranean83 Dispersal of certain lizards across the western end of the Mediterranean84 The origin of certain lizards in Cuba85 The appearance of elephant fossils on "many islands," which are said to have arrived by swimming86 Dispersal of freshwater frogs across oceanic island chains87 Certain frogs reaching Madagascar88 The colonization of Anguilla by green iguanas89 Appearance of certain South American insects90 Dispersals of chameleons across the Indian Ocean91 Origin of certain insects in Caribbean islands92 The origin of mantellid frogs found on the island of Mayotte in the Comoros archipelago, despite the fact that "[a]mphibians are thought to be unable to disperse over ocean barriers because they do not tolerate the osmotic stress of salt water"93 The spread of flightless insects to the Chatham Islands94 The origin of indigenous gekkos in South America95 Origin of crocodile distributions96 The appearance of sloths in South America97 The origin of a group of Australian rodents98 The appearance of land mammals of the Mediterranean islands (also suggesting that "Hippos, elephants, and giant deer reached the islands by swimming")99 The origin of various land reptiles in Western Samoa100 The presence of Crotalus rattlesnakes in Baja California101
Indeed, the review by De Queiroz wrote that "[s]triking examples of oceanic dispersal" include:
(a) Scaevola (Angiospermae: Goodeniaceae) three times from Australia to Hawaii; (b) Lepidium mustards (Angiospermae: Brassicaceae) from North America and Africa to Australia; (c) Myosotis forget-me-nots (Angiospermae: Boraginaceae) from Eurasia to New Zealand and from New Zealand to South America; (d) Tarentola geckos from Africa to Cuba; (e) Maschalocephalus (Angiospermae: Rapateaceae) from South America to Africa; (f) monkeys (Platyrrhini) from Africa to South America; (g) melastomes (Angiospermae: Melastomataceae) from South America to Africa; (h) cotton (Angiospermae: Malvaceae: Gossypium) from Africa to South America; (i) chameleons three times from Madagascar to Africa; (j) several frog genera to and from Madagascar; (k) Acridocarpus (Angiospermae: Malpighiaceae) from Madagascar to New Caledonia; (l) Baobab trees (Angiospermae: Bombacaceae: Adansonia) between Africa and Australia; (m) 200 plant species between Tasmania and New Zealand; (n) many plant taxa between Australia and New Zealand; and (o) Nemuaron (Angiospermae: Atherospermataceae) from Australia (or Antarctica) to New Caledonia.102
Figure 1 of De Queiroz's paper contains a striking map of the world covered in lines criss-crossing back and forth across oceans showing how many species must have traversed oceans to explain their distributions in locations unexpected by traditional biogeography.
It seems clear that there are plenty of examples that contradict the NCSE's simplistic picture of biogeography where the alleged "consistency between biogeographic and evolutionary patterns provides important evidence about the continuity ... [that] would be expected of a pattern of common descent." Somehow all of the above examples got left off the NCSE's reply to Explore Evolution. There seem to be many more "biogeographic conundrums" than the NCSE is letting on.
IV. Testing the Orchard Model and the NCSE's Claims About the Existence of "Nested Patterns" Supporting a "Tree of Life"
Though it gives no citation, the NCSE claims that "The consistency of these sorts of nested patterns cannot be explained without reference to common descent. The creationist 'orchard' is scientifically meaningless, since it makes no predictions." The NCSE's claim is perplexing because, as noted, the NCSE also claimed that "continuity [between biogeographic and evolutionary patterns] is what would be expected of a pattern of common descent, and is not what would be expected with the creationist orchard scheme." (emphasis added) Ignoring the NCSE's inappropriate use of the "creationist" label, the NCSE is thus committing the classic evolutionist fallacy of arguing that opposing views are both unfalsifiable, and falsified by the data.
Regardless, the NCSE is wrong when it claims that the orchard model makes no predictions. If a monophyletic view of common descent predicts "nested patterns," then by the NCSE's own admission a polyphyletic or "orchard" view predicts non-nested patterns. Indeed systematists regularly search for precisely such non-nested patterns in order to identify polyphyletic taxa, a phenomenon effectively predicted by the orchard model. The only idea here that is "meaningless" is the NCSE's claim that universal common descent makes predictions, while the "orchard" model does not (and, by the way, is falsified due to its failed predictions).
Regardless, biogeography is full of incongruent patterns which essentially entail non-nested distribution of species. In fact, Bruce S. Lieberman's treatise Paleobiogeography: Using Fossils to Study Global Change, Plate Tectonics, and Evolution compares the problem of finding incongruent (i.e., non-nested) patterns among different biogeographic hypotheses to the problem of finding incongruent (i.e., non-nested) patterns of traits in different species when constructing phylogenetic trees:
[H]istorical biogeography is the discipline that looks at how groups of organisms have evolved and how their geographic distributions have changed in relation to geological or climatic events. ... In phylogenetic analysis, the arbiter among competing hypotheses suggested by different character systems, i.e. incongruence among characters, is parsimony. The analogous problem in biogeography is what to do when one group suggests one biogeographic pattern, and another group suggests another.103
Analagous to maximizing parsimony in tree-construction, Lieberman notes that vicariance, or land-based separation of organisms, is often preferred, where the explanation that "maximize[es] vicariance, is the one preferred."104 But he notes that there can be "incongruence"105 between biogeographic patterns. Thus in Lieberman's words, when "one group suggests one biogeographic pattern, and another group suggests another," we have a non-nested biogeographical pattern and we find the opposite of the NCSE's claimed "continuity" that supports universal common descent.
In this regard, much of the data discussed in Part III above entails such incongruence and a breakdown in nested patterns of biogeographic distribution of taxa. As seen, such disparate data often require evolutionists to resort to speculative and unfalsifiable hypotheses of oceanic dispersal as a means of transcending traditional methods of migration. This data challenges the "continuity" of biogeographic and evolutionary patterns said to support universal common descent, but might be expected under an orchard model.
In fact, it is not only within biogeography that we find non-nested patterns, and it important to fact-check the NCSE's claim that we always find "nested patterns" pointing to a "tree of life." An article in New Scientist in January 2009 was titled, "Why Darwin Was Wrong about the Tree of Life." Contrary to the NCSE's claim that we always find "nested patterns" which "cannot be explained without reference to common descent," the article reported a major "problem" encountered by molecular systematists, namely that "different genes told contradictory evolutionary stories." The article observed that with the sequencing of the genes and proteins of various living organisms, the tree of life fell apart:
"For a long time the holy grail was to build a tree of life," says Eric Bapteste, an evolutionary biologist at the Pierre and Marie Curie University in Paris, France. A few years ago it looked as though the grail was within reach. But today the project lies in tatters, torn to pieces by an onslaught of negative evidence. Many biologists now argue that the tree concept is obsolete and needs to be discarded. "We have no evidence at all that the tree of life is a reality," says Bapteste. That bombshell has even persuaded some that our fundamental view of biology needs to change.106
Of course, these scientists are all committed evolutionists, which makes their admissions all the more weighty. And these arguments apply not just to the base of the tree of life, but also to higher branches where processes like horizontal gene transfer are not thought to be prevalent, as the article observed that "the evolution of animals and plants isn't exactly tree-like either."125 To reiterate, the basic problem is that one gene or protein yields one version of the "tree of life," while another gene or protein yields an entirely different tree. As the New Scientist article stated:
The problems began in the early 1990s when it became possible to sequence actual bacterial and archaeal genes rather than just RNA. Everybody expected these DNA sequences to confirm the RNA tree, and sometimes they did but, crucially, sometimes they did not. RNA, for example, might suggest that species A was more closely related to species B than species C, but a tree made from DNA would suggest the reverse.107
Likewise, leading evolutionary bioinformatics specialist W. Ford Doolittle explains, "Molecular phylogenists will have failed to find the 'true tree,' not because their methods are inadequate or because they have chosen the wrong genes, but because the history of life cannot properly be represented as a tree."108 The NCSE may claim that this problem is only encountered when one tries to reconstruct the evolutionary relationships of microorganisms, such as bacteria, which can swap genes through a process called "horizontal gene transfer," thereby muddying any phylogenetic signal. But the tree of life is challenged even among higher organisms where such promiscuous gene-swapping across taxa is not thought to not take place. As the article explains:
Syvanen recently compared 2,000 genes that are common to humans, frogs, sea squirts, sea urchins, fruit flies and nematodes. In theory, he should have been able to use the gene sequences to construct an evolutionary tree showing the relationships between the six animals. He failed. The problem was that different genes told contradictory evolutionary stories. This was especially true of sea-squirt genes. Conventionally, sea squirts--also known as tunicates--are lumped together with frogs, humans and other vertebrates in the phylum Chordata, but the genes were sending mixed signals. Some genes did indeed cluster within the chordates, but others indicated that tunicates should be placed with sea urchins, which aren't chordates. "Roughly 50 per cent of its genes have one evolutionary history and 50 per cent another," Syvanen says.109
Even among higher organisms, "[t]he problem was that different genes told contradictory evolutionary stories," leading Syvanen to say, regarding the relationships of these higher groups, "We've just annihilated the tree of life." This directly contradicts the NCSE's claim that there exists a "tree of life" with "nested patterns" which "cannot be explained without reference to common descent."
Other scientists agree with the conclusions of the New Scientist article. Looking higher up the tree, a recent study published in Science tried to construct a phylogeny of animal relationships but concluded that "[d]espite the amount of data and breadth of taxa analyzed, relationships among most [animal] phyla remained unresolved."110 Likewise, Carl Woese, a pioneer of evolutionary molecular systematics, observed that these problems extend well beyond the base of the tree of life: "Phylogenetic incongruities [conflicts] can be seen everywhere in the universal tree, from its root to the major branchings within and among the various taxa to the makeup of the primary groupings themselves."111
Likewise, National Academy of Sciences biologist Lynn Margulis has had harsh words for the field of molecular systematics, which Hillis studies. In her article, "The Phylogenetic Tree Topples," she explains that "many biologists claim they know for sure that random mutation (purposeless chance) is the source of inherited variation that generates new species of life and that life evolved in a single-common-trunk, dichotomously branching-phylogenetic-tree pattern!" But she dissents from that view and attacks the evolutionary systematists, noting, "Especially dogmatic are those molecular modelers of the 'tree of life' who, ignorant of alternative topologies (such as webs), don't study ancestors."112
Striking admissions of troubles in reconstructing the "tree of life" also came from a paper in the journal PLoS Biology entitled, "Bushes in the Tree of Life." The authors acknowledge that "a large fraction of single genes produce phylogenies of poor quality," observing that one study "omitted 35% of single genes from their data matrix, because those genes produced phylogenies at odds with conventional wisdom."113 The paper suggests that "certain critical parts of the [tree of life] may be difficult to resolve, regardless of the quantity of conventional data available."114 The paper even contends that "[t]he recurring discovery of persistently unresolved clades (bushes) should force a re-evaluation of several widely held assumptions of molecular systematics."115
Unfortunately, one assumption that these evolutionary biologists are not willing to consider changing is the assumption that neo-Darwinism and universal common ancestry are correct. Meanwhile, as far as the data are concerned, the New Scientist article admits, "Ever since Darwin the tree has been the unifying principle for understanding the history of life on Earth," but because "different genes told contradictory evolutionary stories," the notion of a tree of life is now quickly becoming a vision of the past -- as the article stated, it's being "annihilated."
The NCSE claims that the "orchard" concept of EE is "meaningless" but it would seem to predict the precise non-nested phylogenetic data reported in New Scientist and the non-nested biogeographic data reported in Part III above. Perhaps the reason why different genes are telling "different evolutionary stories" and "one group suggests one biogeographic pattern, and another group suggests another" is because the genes and organisms have wholly different stories to tell, namely stories that indicate that not all living organisms are ancestrally related, thereby fulfilling a testable prediction of the orchard model.
V. Holding EE to a Double Standard Compared to Similar Textbooks
EE was designed to provide a supplementary introductory unit on evolution, providing students with both the evidence for and against neo-Darwinism. The textbook would be most appropriate for an upper level high school course or an introductory college course. Thus, one would expect that any complaints that the NCSE would make about topics or sources discussed in EE would not apply to the average high school or college level biology textbook treatment of evolution. However, as seen below, many mainstream biology textbooks would be subject to the same complaints that the NCSE levels at EE. Strangely, the NCSE is silent about those textbooks. The NCSE is holding EE to a double standard.
A. Double Standard on EE's Discussion of Historical Ideas about the Fixity of Species
As noted in Part I, contrary to the NCSE's claims, EE does not advocate for the fixity of species. But like many textbooks EE does discuss the historical development of biological thought and the fact that before Darwin's day, many did believe in the fixity of species. The NCSE takes issue with EE for discussing the fact that Darwin used the evidence from biogeography to attack the concept of the fixity of species. The NCSE cites John Wilkins stating: "The idea that species were universally thought to be fixed prior to Darwin is simply wrong -- many creationist thinkers of the classical period through to the 19th century thought that species could change."
Wilkins is undoubtedly correct, but his words do not contradict EE. In the passage that mentions fixity of species, EE never claims that prior to Darwin, species were "universally thought to be fixed" (Wilkins' words). Rather, EE merely claims that the ideas about fixity of species were "popular in his [Darwin's] day." As EE states:
Darwin was using this evidence to challenge a theory that was popular in his day, but is almost unheard of now: the fixity of species. (EE, pg. 76)
The NCSE misrepresents EE, and EE's observation that the fixity of species was "popular" in Darwin's day is utterly uncontroversial. In fact nearly identical claims are found in numerous other mainstream biology textbooks. A few examples include:
Campbell, Reece, Mitchell, and Taylor's, Biology: Concepts and Connections (4th ed., 2003): "The Greek philosopher Aristotle, whose views had an enormous impact on Western culture, generally held that species are fixed, or permanent, and do not evolve. Judeo-Christian culture fortified this idea with a literal interpretation of the Book of Genesis, holding that all species were individually designed by a divine creator. The idea that all species are static in form and inhabit an Earth that is at most 6,000 years old dominated the intellectual and cultural climate of the Western world for centuries."116 "Aristotle and the Judeo-Christian culture held that species are fixed. Fossils suggested that life-forms change."117 Campbell and Reece's Biology (6th ed., 2002): "In this view of life, which prevailed for over 2,000 years, species are permanent, are perfect, and do not evolve."118 Campbell and Reece's Biology (7th ed., 2005): "Darwin's view of life contrasted sharply with traditional beliefs ... of life that had been created at the beginning and remained unchanged ever since. Darwin's book challenged a worldview that had been prevalent for centuries."119 Cecie Starr's Biology: Concepts and Applications (2006): "At one time Europeans viewed nature as a great Chain of Being extending from the 'lowest' forms of life to humans, and on to spiritual beings. Each kind of being, or species as it was called, was one separate link in the chain. All of the links had been designed and forged at the same time at one center of creation. They had not changed since. Once all the links were discovered and described, the meaning of life would be revealed."120 Kenneth Miller and Joseph Levine's Biology (2008): "Most Europeans in Darwin's day believed that ... [s]ince that original creation, they concluded, neither the planet nor its living species had changed. A robin, for example, has always looked and behaved as robins had in the past."121 Scott Freeman's Biological Science (2005): "When Darwin published his theory in 1859 ... the leading explanation for the diversity of organisms was a theory called special creation. ... The theory of special creation also maintained that species were immutable, or incapable of change, and thus had been unchanged since the moment of their creation."122 Sylva S. Mader's Essentials of Biology (2007): "Prior to Darwin, lay people had an entirely different way of looking at the world. They believed ... that since the time of creation, species had remained exactly the same. ... A noted zoologist at the time, Georges Cuvier, founded the science of paleontology, ... [Cuvier] believed in the fixity of species..."123
It seems clear that EE's statement that the fixity of species was "popular in [Darwin's] day" is utterly uncontroversial, and that the NCSE is nitpicking over a non-issue.
As a final note, the NCSE tries to paint EE as arguing for "fixity of something" due to "later arguments about the limits on the evolution of finches" claiming that EE is "merely following the lead of creationists like George MacReady Price in the 1930s, who replaced the notion of species fixity with fixity of Biblical 'kinds.'" EE makes no such claims. Once again the NCSE is trying to tie EE to creationists who have absolutely nothing to do with this textbook. Observing that there are limits to finch evolution does not make one a Biblical creationist. Regardless, if the NCSE objects to a position that claims there is "fixity of something," then perhaps EE would not be wrong if it were to characterize the views of neo-Darwinists as believing in "unlimited change." Otherwise, they too must believe in the NCSE's vaguely described position of "fixity of something," thereby mooting the NCSE's complaint. Indeed, in its response to EE on natural selection, the NCSE argues that there are limits to the amount of change that can be effected by natural selection. The NCSE's complaint here is moot.
B. Double Standards over the NCSE's Favorite Pet Citations
Oddly, while the NCSE protests EE's alleged overuse of examples of island biogeography, the NCSE also complains about EE's apparent failure to cite "seminal works like Macarthur and Wilson's Island Theory of Biogeography." Many high school or college-level introductory biology textbooks do not even list direct citations or references for points in the text, so the fact that EE lists such references at all places it a cut above many other comparable textbooks. However, even some college-level evolutionary biology textbooks do not cite the NCSE's apparently favorite book on island biogeography:
Strickberger's Evolution (4th ed., 2008, by Brian K. Hall and Benedikt Hallgrimsson) Evolution by Nicholas H. Barton, Derek E. G. Briggs, Jonathan A. Eisen, David B. Goldstein, Nipam H. Patel (Cold Spring Harbor Laboratory, 2007) Evolutionary Analysis, by Scott Freeman and Jon C. Herron (3rd ed., Pearson/Prentice Hall, 2004) Evolution: An Introduction by Stephen C. Stearns and Rolf F. Hoekstra (2nd ed., Oxford University Press, 2005) Even John C. Briggs' treatise Global Biogeography does not list MacArthur and Wilson's book in its references.
Macarthur and Wilson's Island Theory of Biogeography may be a great resource, but why isn't the NCSE nitpicking against these other textbooks for not citing to its preferred source?
C. Double Standard on "Biogeographic Provinces"
Likewise, the NCSE protests that EE does not mention the concept of the "biogeographic province." Again, a survey of current introductory biology and evolutionary biology textbooks shows that many recent textbooks also do not discuss the term "biogeographic province" nor related terms like "ecological region" or "bioregion."124 EE does not deviate from what is standard treatment of this issue in many introductory biology textbooks.
D. Double Standard on Tropical Biodiversity
The NCSE protests that "There is no discussion of forces driving tropical biodiversity" in EE. But it never elaborates on this charge to explain why tropical biodiversity should necessarily be included in EE, nor does it mention that other introductory biology textbooks also do not discuss this topic at all when covering biogeography.
E. Double Standard on EE's Definition of Macroevolution.
The NCSE nitpicks over EE's definition of macroevolution as "the origin of new large-scale features such as organs or body plans," calling it "idiosyncratically defined." EE's definition of macroevolution focuses on the origin of major new biological features. In fact, such an emphasis is found in the definitions for "macroevolution" found in many biology textbooks:
Kenneth Miller and Joseph Levine's Biology (2008): "large-scale evolutionary changes that take place over long periods of time." Saying that macroevolution entails the origin of "large-scale" features, this textbook uses some of the very same language in EE. Sylva S. Mader's Essentials of Biology (2007): "Large-scale evolutionary change, such as the formation of new species." Again, this textbook uses much the same language that EE does. Campbell and Reece's Biology (5th ed., 1999): "Evolutionary change on a grand scale, encompassing the origin of novel designs..." Again, this fits neatly with EE's definition--a definition that looks at substantive innovations of biological novelty. Belk & Maier's Biology: Science for Life (2010): "Large-scale evolutionary change, usually referring to the origin of new species." This is another example of a textbook using the same language about "large-scale evolutionary change" that EE does.
In sum, we see a double standard at work, for many other biology textbooks use highly similar definitions of macroevolution.
F. Double Standard on the Amount of Space EE Devotes to Biogeography
The NCSE charges that "Biogeography is a much larger topic than Explore Evolution makes it seem to be." It's not entirely clear what the NCSE would like to see changed. Nevertheless, this criticism also seems highly suspect. EE devotes an entire chapter (6 pages of text), to the topic of biogeography. Compared to the amount of space that many introductory biology textbooks devote to biogeography, it would seem that EE's treatment is highly similar, and in fact more expansive:
|Textbook||Number of Pages Listed in Index Under "Biogeography"|
|Glencoe's Biology: The Dynamics of Life (Florida Edition, 2006||0|
|Campbell, Reece, Mitchell, and Taylor's, Biology: Concepts and Connections (4th ed., 2003)||1|
|Kenneth Miller and Joseph Levine's Biology (2008)||1|
|Raven, Johnson, Losos and Singer's Biology (7th ed., 2005)||2|
|Sylva S. Mader's Essentials of Biology (2007)||3|
|Belk & Maier's Biology: Science for Life (2010)||5|
|Scott Freeman's Biological Science (2005)||5|
|Cecie Starr's Biology: Concepts and Applications (2006)||5|
|Campbell and Reece's Biology (7th ed., 2005)||5|
If the NCSE complains that EE allegedly devotes insufficient space to biogeography, then it seems to be holding EE to another double-standard. Not to diminish the importance of biogeography to the study of the evidence for and against neo-Darwinian evolution, but many textbooks seem to give it a more limited treatment than they do other topics.
VI. The NCSE Misrepresents EE's Attitude toward Inquiry in Biogeography
The NCSE accuses EE of "surrender[ing]" to ignorance: "Scientific inquiry takes empirically rooted disagreement as a starting point for further research, not as a chance to declare that 'there may not be much further debate' and 'the issue is likely to remain exactly where it is.'" Given that the NCSE's entire purpose for existence is to tell students that the topic of origins is fundamentally settled with the answer of neo-Darwinian evolution, its complaint here seems tremendously hypocritical. Regardless, the NCSE has omitted key parts of EE's text, creating a false impression. EE in fact says:
Frankly, at one level there may not be much further debate about biogeography. Unless somebody, somewhere, makes an astounding discovery on one side or the other, the issue is likely to remain exactly where it is. (EE, pg. 79)
EE here makes a plainly unobjectionable point: "Unless somebody, somewhere, makes an astounding discovery," this debate will not move forward. The implication of course is that students should be encouraged to be inspired go to out and do research to move the debate forward! The NCSE does not quote this portion of EE's text, as it would encourage students to engage in further research on the topic of biogeography, not stifle inquiry.
Indeed, EE has a purpose in explaining why biogeographical evidence is not the final arbiter of the debate over neo-Darwinism. Since the biogeographic data is compatible with the views of both proponents and critics of neo-Darwinism, EE tries to help students to ask the right questions in order to assess neo-Darwinian theory. The textbook thus asks:
How much creative power do evolutionary mechanisms possess? That is a key question in the current controversy about Darwinian evolution. Since understanding this mechanism is vitally important to our understanding of the history of life, and since Darwin and modern neo-Darwinists have claimed that natural selection can indeed produce large-scale biological change, the next part of this book will examine the arguments for and against the creative power of this mechanism. (EE, pgs. 79-80)
Thus, EE is actually teaching students how to engage in proper inquiry by asking the right questions that will yield the most important answers to fundamental questions about origins. This is an essential skill for scientists, who must learn to devise experiments and studies to answer the most fundamental questions. The chapter on biogeography helps students to understand how it does, or does not, answer key questions about neo-Darwinism.
In one final example where the NCSE misrepresents EE, it states: "Geologically recent adaptive radiations have often generated variations exceeding that seen within whole families, yet the authors call these 'only small-scale variations in existing traits.'" The NCSE made this statement in reference to a group of Hawaiian plants called silverswords, an example not even covered in EE. Thus, EE could not have said that silversword diversity represents "only small-scale variations in existing traits" because EE in fact said absolutely nothing about Hawaiian silverswords. The NCSE continues:
By making such a sweeping and imbalanced generalization, Explore Evolution misinforms students about the actual evidence at hand. By making the claims without explaining the basis for them, Explore Evolution makes it impossible for students to explore these ideas in any additional depth, once again hindering inquiry, rather than encouraging and supporting true scientific investigation.
But as we have seen, the NCSE identified no actual errors in the text of EE on biogeography, and repeatedly misrepresented or ignored what EE actually said on the subject. EE provides extensive documentation supporting its claims, and as discussed in this response to the NCSE, EE's claims are backed by credible authorities. The NCSE's critique of EE on biogeography seems to be an exercise in closing its eyes to any evidence that supports EE's case. The NCSE considers "true scientific investigation" to be only that which supports neo-Darwinism, but the NCSE has no right to criticize anyone for not sufficiently advocating inquiry-based science education. Thankfully, EE exists to provide students with credible alternative scientific viewpoints. The NCSE must resort to specious critiques and ignore contrary biogeographical data to prevent those viewpoints from being heard.
* All quotes of the NCSE in this document were downloaded from the NCSE website's response to EE on Biogeography on October 29, 2008.
[1.] The sciences, especially historical sciences like evolutionary biogeography, do not deal in 100 percent proof. But the term "standard of proof" is used here to recognize that all scientists do accept that scientific evidence can point in one direction or another, even if 100 percent proof is never attained.
[2.] Claudia A. M. Russo, Naoko Takezaki, and Masatoshi Nei, "Molecular Phylogeny and Divergence Times of Drosophilid Species," Molecular Biology and Evolution, Vol. 12(3):391-404 (1995).
[3.] Steve Olson, Evolution in Hawaii: A Supplement to Teaching About Evolution and the Nature of Science, pg. 15 (National Academy Press, 2004). See also Patrick O'Grady, and Rob DeSalle, "Out of Hawaii: the origin and biogeography of the genus Scaptomyza (Diptera: Drosophilidae)," Biology Letters, Vol. 4:195--199 (2008).
[4.] Kenneth Y. Kaneshiro, Rosemary G. Gillespie, and Hampton L. Carson, "Chromosomes and Male Genitalia of Hawaiian Drosophila," in Hawaiian Biogeography: Evolution on a Hot Spot Archipelago, pg. 59 (Smithsonian Institution, 1995).
[5.] Id. (quoting Throckmorton).
[6.] Claudia A. M. Russo, Naoko Takezaki, and Masatoshi Nei, "Molecular Phylogeny and Divergence Times of Drosophilid Species," Molecular Biology and Evolution, Vol. 12(3):391-404 (1995); Kenneth Y. Kaneshiro, Rosemary G. Gillespie, and Hampton L. Carson, "Chromosomes and Male Genitalia of Hawaiian Drosophila," in Hawaiian Biogeography: Evolution on a Hot Spot Archipelago, pg. 59 (Smithsonian Institution, 1995).
[7.] Walter Hackman, "The relation between the genera Scaptomyza and Drosophila (Diptera, Drosophilidae)," Ann. Ent. Fenn., Vol. 48:97-104 (1982).
[8.] Walter Hackman, "The relation between the genera Scaptomyza and Drosophila (Diptera, Drosophilidae)," Ann. Ent. Fenn., Vol. 48:97-104 (1982). See also the discussion of Titanochaeta in David A. Grimaldi, "A Phylogenetic Revised Classification of Genera in the Drosophilidae (Diptera)," Bulletin of the American Museum of Natural History, Vol. 197:1-144 (1990).
[9.] Claudia A. M. Russo, Naoko Takezaki, and Masatoshi Nei, "Molecular Phylogeny and Divergence Times of Drosophilid Species," Molecular Biology and Evolution, Vol. 12(3):391-404 (1995).
[11.] Patrick O'Grady, and Rob DeSalle, "Out of Hawaii: the origin and biogeography of the genus Scaptomyza (Diptera: Drosophilidae)," Biology Letters, Vol. 4:195--199 (2008).
[12.] Kenneth Y. Kaneshiro, Rosemary G. Gillespie, and Hampton L. Carson, "Chromosomes and Male Genitalia of Hawaiian Drosophila," in Hawaiian Biogeography: Evolution on a Hot Spot Archipelago, pg. 59 (Smithsonian Institution, 1995).
[13.] Claudia A. M. Russo, Naoko Takezaki, and Masatoshi Nei, "Molecular Phylogeny and Divergence Times of Drosophilid Species," Molecular Biology and Evolution, Vol. 12(3):391-404 (1995).
[14.] Steve Olson, Evolution in Hawaii: A Supplement to Teaching About Evolution and the Nature of Science, pg. 18 (National Academy Press, 2004).
[15.] "Darwin's mockingbirds knock finches off perch," at http://www.nhm.ac.uk/about-us/news/2008/november/darwins-mockingbirds-knock-finches-off-perch.html
[16.] Frank J. Sulloway, "Darwin and His Finches: The Evolution of a Legend," Journal of the History of Biology, Vol. 15(1):1-53 (Spring, 1982).
[17.] Collen Belk & Virginia Borden Maier, Biology: Science for Life, pg. 235 (Pearson / Benjamin Cummings, 2010).
[18.] Robert J. Whittaker, Island Biogeography: Ecology, Evolution, and Conservation, pg. 96 (Oxford University Press, 1998) (emphasis added).
[19.] Jeffrey Podos and Stephen Nowicki, "Beaks, Adaptation, and Vocal Evolution in Darwin's Finches," BioScience, Vol. 54(6):501-510 (June 2004).
[20.] EE, pg. 93, citing Peter R. Grant and B. Rosemary Grant, "Unpredictable evolution in a 30-year study of Darwin's finches," Science, Vol. 296:707-711 (2002).
[21.] Geerat J. Vermeij, "Island Life: A View from the Sea," in Frontiers of Biogeography: New Directions in the Geography of Nature, pgs. 240-241 (Edited by Mark V. Lomolino and Lawrence R. Heaney, Sinauer, 2004).
[22.] Id. at 241 (internal citations removed).
[23.] Britannica Concise Encyclopedia at http://www.answers.com/topic/darwin-s-finches and http://www.britannica.com/EBchecked/topic/223745/Galapagos-finch. Likewise, Wikipedia states, "The birds are all about the same size (10--20 cm)." http://en.wikipedia.org/wiki/Darwin's_finches
[24.] Jonathan Weiner, The Beak of the Finch, pg.43 (Vintage Books, 1994).
[26.] Robert J. Whittaker, Island Biogeography: Ecology, Evolution, and Conservation, pg. 96 (Oxford University Press, 1998) (internal citations removed).
[27.] Whittaker calls them the "Hawaiian equivalents to Darwin's finches." Robert J. Whittaker, Island Biogeography: Ecology, Evolution, and Conservation, pg. 97 (Oxford University Press, 1998).
[28.] James H. Brown and Mark V. Lomolino, Biogeography, pg. 247 (Sinauer, 1998).
[29.] C. Barry Cox and Peter D. Moore, Biogeography: An Ecological and Evolutionary Approach, pg. 160 (Blackwell Science, 1993).
[30.] Id. (emphasis added).
[31.] Id. at 161.
[32.] Cheryl L. Tarr and Robert C. Fleischer, "Evolutionary Relationships of the Hawaiian Honeycreepers (Aves, Drepanidinae)," in Hawaiian Biogeography: Evolution on a Hot Spot Archipelago, pg. 158 (Smithsonian Institution, 1995).
[33.] William Dembski and Jonathan Wells, The Design of Life, pg. 107 (FTE, 2008).
[34.] James H. Brown and Mark V. Lomolino, Biogeography, pg. 247 (Sinauer, 1998).
[35.] For example, the following biology textbooks do not mention cichlids in their discussions of biogeography: Kenneth Miller and Joseph Levine, Biology (Pearson / Prentice Hall, 2008); Collen Belk & Virginia Borden Maier, Biology: Science for Life, (Pearson / Benjamin Cummings, 2010); Sylva S. Mader's Essentials of Biology (McGraw Hill, 2007); Glencoe's Biology: The Dynamics of Life (Florida Edition, 2006); Campbell, Reece, Mitchell, and Taylor's, Biology: Concepts and Connections (4th ed., 2003).
[36.] See M.H.A. Keenleyside, Cichlid fishes Behaviour, ecology and evolution (Chapman Hall, 1991).
[37.] A. J. Ribbink, A. C. Marsh, & B. J. Sharp, "The zoogeography, ecology and taxonomy of the genus Labeotropheus Ahl, 1927, or Lake Malawi (Pisces: Cichlidae)," Zoological Journal of the Linnaean Society, Vol. 79:223-243 (1983).
[38.] Sylva S. Mader, Essentials of Biology, pg. 276 (Thomson Brooks/Cole, 2007) (emphases removed).
[39.] See Plate 7 in Christopher R. Scotese, "Cenozoic and Mesozoic Paleogeography: Changing Terrestrial Biogeographic Pathways," in Frontiers of Biogeography: New Directions in the Geography of Nature, pgs. 240-241 (Edited by Mark V. Lomolino and Lawrence R. Heaney, Sinauer, 2004).
[40.] C. Barry Cox & Peter D. Moore, Biogeography: An Ecological and Evolutionary Approach, pg. 186 (Blackwell Science, 1993).
[41.] Zhe-Xi Luo, Qiang Ji, John R. Wible, Chong-Xi Yuan, "An Early Cretaceous Tribosphenic Mammal and Metatherian Evolution," Science, Vol. 302:1934-1940 (December 12, 2003).
[42.] Bob Beale, "World's oldest marsupial found in China," ABC Science (December 12, 2003), at http://www.abc.net.au/science/articles/2003/12/12/1008521.htm
[43.] Randolphe E. Schmid, "Oldest Marsupial Remains Found in Northeast China," RedOrbit, December 11, 2003 at http://www.redorbit.com/news/science/33864/oldest_marsupial_remains_found_in_northeast_china/
[44.] C. Barry Cox & Peter D. Moore, Biogeography: An Ecological and Evolutionary Approach, pg. 186 (Blackwell Science, 1993).
[45.] Id. at 187.
[46.] Id. at 188.
[47.] John P. Hunter and Christine M. Janis, "'Garden of Eden' or 'Fool's Paradise'? Phylogeny, dispersal, and the southern continent hypothesis of placental mammal origins," Paleobiology, Vol. 32(3):339--344 (2006).
[48.] C. Barry Cox & Peter D. Moore, Biogeography: An Ecological and Evolutionary Approach, pg. 185 (Blackwell Science, 1993).
[50.] The NCSE uses this tactic so much that Paul Nelson devoted an entire response to refuting the NCSE on this one fallacious argument. See Paul Nelson, "The Creationism Gambit" at http://www2.exploreevolution.com/exploreEvolutionFurtherDebate/2009/03/the_creationism_gambit_1.php
[51.] Simon Conway Morris, Life's Solution: Inevitable Humans in a Lonely Universe, pg. 127 (Cambridge University Press, 2003).
[52.] Id. at 127-128 (emphasis added).
[53.] Laurie J. Witt & Janalee P. Caldwell, Herpetology, pg. 26 (3rd ed., Elsevier, 2009).
[54.] Guillaume Lecointre & HervÃ© Le Guyader, The Tree of Life: a Phylogenetic Classification, pg. 16 (Harvard University Press, 2006) (emphasis added).
[55.] Olivier Rieppel, "What Happens When the Language of Science Threatens to Break Down in Systematics: A Popperian Perspective" in Milestones in Systematics, pg. 78 (David Malcolm Williams, Peter L. Forey, CRC Press, 2004).
[56.] David R. Begun, "Hominid family values: morphological and molecular data on relations among great apes and humans," in The Mentalities of Gorillas and Orangutans: Comparative Perspectives, pg. 8 (Sue Taylor Parker, Robert W. Mitchell, H. Lyn Miles eds., Cambridge University Press, 1999).
[57.] Alan de Queiroz, "The resurrection of oceanic dispersal in historical biogeography," Trends in Ecology and Evolution, Vol.20(2):68-73 (February 2005).
[61.] See John C. Briggs, Global Biogeography, pg. 124 (Elsevier Science, 1995); Alain Houle, "The Origin of Platyrrhines: An Evaluation of the Antarctic Scenario and the Floating Island Model," American Journal of Physical Anthropology, Vol. 109:541--559 (1999).
[62.] Carlos G. Schrago and Claudia A. M. Russo, "Timing the origin of New World monkeys," Molecular Biology and Evolution, Vol. 20(10):1620--1625 (2003); John J. Flynn and AndrÃ© R. Wyss, "Recent advances in South American mammalian paleontology," Trends in Ecology and Evolution, Vol. 13(11):449-454 (November, 1998); C. Barry Cox & Peter D. Moore, Biogeography: An Ecological and Evolutionary Approach, pg. 185 (Blackwell Science, 1993).
[63.] Carlos G. Schrago and Claudia A. M. Russo, "Timing the origin of New World monkeys," Molecular Biology and Evolution, Vol. 20(10):1620--1625 (2003).
[64.] Anthony Hallam, An Outline of Phanerozoic Biogeography, pg. 166 (Oxford University Press, 1994). See also Walter Carl Hartwig, "Patterns, Puzzles and Perspectives on Platyrrhine Origins," in Integrative Paths to the Past: Paleoanthropological Advances in Honor of F. Clark Howell, pg. 80 (Edited by Robert S. Corruccini and Russell L. Ciochon, Prentice Hall, 1994).
[65.] Walter Carl Hartwig, "Patterns, Puzzles and Perspectives on Platyrrhine Origins," in Integrative Paths to the Past: Paleoanthropological Advances in Honor of F. Clark Howell, pg. 69 (Edited by Robert S. Corruccini and Russell L. Ciochon, Prentice Hall, 1994).
[66.] John G. Fleagle and Christopher C. Gilbert, "The Biogeography of Primate Evolution: The Role of Plate Tectonics, Climate and Chance," in Primate Biogeography: Progress and Prospects, pgs. 393-394 (Shawn M. Lehman and John G. Fleagle, eds., Springer, 2006) (emphasis added).
[67.] Adrienne L. Zihlman, The Human Evolution Coloring Book, 4-11 (Harper Collins, 2000).
[68.] John G. Fleagle and Christopher C. Gilbert, "The Biogeography of Primate Evolution: The Role of Plate Tectonics, Climate and Chance," in Primate Biogeography: Progress and Prospects, pg. 394 (Shawn M. Lehman and John G. Fleagle, eds., Springer, 2006).
[69.] Id. at 394-395 (emphasis added).
[70.] Id. at 394.
[71.] Id. at 404.
[72.] Id. at 404 (emphasis added).
[73.] Id. at 403.
[74.] Walter Carl Hartwig, "Patterns, Puzzles and Perspectives on Platyrrhine Origins," in Integrative Paths to the Past: Paleoanthropological Advances in Honor of F. Clark Howell, pg. 76 (Edited by Robert S. Corruccini and Russell L. Ciochon, Prentice Hall, 1994).
[75.] Id. at 84 (emphasis added). Note: "waif dispersal" in this case refers to "island-hopping."
[76.] John G. Fleagle and Christopher C. Gilbert, "The Biogeography of Primate Evolution: The Role of Plate Tectonics, Climate and Chance," in Primate Biogeography: Progress and Prospects, pg. 395 (Shawn M. Lehman and John G. Fleagle, eds., Springer, 2006) (emphases added).
[77.] Anthony Hallam, An Outline of Phanerozoic Biogeography, pg. 166 (Oxford University Press, 1994).
[78.] John C. Briggs, Global Biogeography, pg. 93 (Elsevier Science, 1995).
[79.] Id. at 124.
[80.] Susan Fuller, Michael Schwarz, and Simon Tierney, "Phylogenetics of the allodapine bee genus Braunsapis: historical biogeography and long-range dispersal over water," Journal of Biogeography, Vol. 32:2135--2144 (2005).
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[82.] Philip D. Rabinowitz & Stephen Woods, "The Africa--Madagascar connection and mammalian migrations," Journal of African Earth Sciences, Vol. 44:270--276 (2006); Anne D. Yoder, Melissa M. Burns, Sarah Zehr, Thomas Delefosse, Geraldine Veron, Steven M. Goodman, & John J. Flynn, "Single origin of Malagasy Carnivora from an African ancestor," Nature, Vol. 421:734-777 (February 13, 2003).
[83.] Michael Veith, Christian Mayer, Boudjema Samraoui, David Donaire Barroso, and Serge Bogaerts, "From Europe to Africa and vice versa: evidence for multiple intercontinental dispersal in ribbed salamanders (Genus Pleurodeles)," Journal of Biogeography, Vol. 31:159--171 (2004).
[84.] S. Carranza, D. J. Harris, E. N. Arnold, V. Batista and J. P. Gonzalez de la Vega, Phylogeography of the lacertid lizard, Psammodromus algirus, in Iberia and across the Strait of Gibraltar, Journal of Biogeography, Vol. 33:1279--1288 (2006).
[85.] Alan de Queiroz, "The resurrection of oceanic dispersal in historical biogeography," Trends in Ecology and Evolution, Vol.20(2):68-73 (February 2005).
[86.] Richard John Huggett, Fundamentals of Biogeography, pg. 60 (Routledge, 1998).
[87.] G. John Measey, Miguel Vences, Robert C. Drewes, Ylenia Chiari, Martim Melo, and Bernard Bourles, "Freshwater paths across the ocean: molecular phylogeny of the frog Ptychadena newtoni gives insights into amphibian colonization of oceanic islands," Journal of Biogeography, Vol. 34:7--20 (2007).
[88.] Miguel Vences, Joachim Kosuch, Mark-Oliver RÃ¶del, Stefan LÃ¶tters, Alan Channing, Frank Glaw and Wolfgang BÃ¶hme, "Phylogeography of Ptychadena mascareniensis suggests transoceanic dispersal in a widespread African- Malagasy frog lineage," Journal of Biogeography, Vol. 31:593--601 (2004).
[89.] Ellen J. Censky, Karim Hodge, & Judy Dudley, "Over-water dispersal of lizards due to hurricanes," Nature, Vol. 395:556 (October 8, 1998).
[90.] C. Amedegnato 1993. African-American relationships in the Acridians (Insecta, Orthoptera). In: George W, Lavocat R, editors. The Africa-South America connection. Oxford: Clarendon Press. p 59--75, cited in Alain Houle, "The Origin of Platyrrhines: An Evaluation of the Antarctic Scenario and the Floating Island Model," American Journal of Physical Anthropology, Vol. 109:541--559 (1999).
[91.] C. J. Raxworthy, M. R. J. Forstner, & R. A. Nussbaum, "Chameleon radiation by oceanic dispersal," Nature, Vol. 415, 784--787 (February 14, 2002).
[92.] Nichols SW. 1988. Systematics and biogeography of West Indian Scaritinae (Coleoptera: Carabidae) (Florida, Mexico). Ph.D. thesis, Cornell University, cited in Alain Houle, "The Origin of Platyrrhines: An Evaluation of the Antarctic Scenario and the Floating Island Model," American Journal of Physical Anthropology, Vol. 109:541--559 (1999).
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[100.] Gill BJ. 1993. The land reptiles of western Samoa. J R Soc N Z 23:79--89, cited in Alain Houle, "The Origin of Platyrrhines: An Evaluation of the Antarctic Scenario and the Floating Island Model," American Journal of Physical Anthropology, Vol. 109:541--559 (1999).
[101.] Stewart SG. 1990. Karyotypes of six rattlesnake (Crotalus) taxa of Baja California and selected Gulf Islands. Ph.D. thesis, California State University, Dominguez Hills, cited in Alain Houle, "The Origin of Platyrrhines: An Evaluation of the Antarctic Scenario and the Floating Island Model," American Journal of Physical Anthropology, Vol. 109:541--559 (1999).
[102.] Alan de Queiroz, "The resurrection of oceanic dispersal in historical biogeography," Trends in Ecology and Evolution, Vol.20(2):68-73 (February 2005).
[103.] Bruce S. Lieberman, Paleobiogeography: Using Fossils to Study Global Change, Plate Tectonics, and Evolution, pg. 114 (Kluwer Academic Press, 2000) (emphasis added).
[104.] Id. at 124.
[105.] Id. at 135.
[106.] Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009) (emphasis added).
[108.] W. Ford Doolittle, "Phylogenetic Classification and the Universal Tree," Science, Vol. 284:2124-2128 (June 25, 1999).
[109.] Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009).
[110.] Antonis Rokas, Dirk Krueger, Sean B. Carroll, "Animal Evolution and the Molecular Signature of Radiations Compressed in Time," Science, Vol. 310:1933-1938 (Dec. 23, 2005).
[111.] Carl Woese "The Universal Ancestor," Proceedings of the National Academy of Sciences USA, Vol. 95:6854-9859 (June, 1998) (emphasis added).
[112.] Lynn Margulis, "The Phylogenetic Tree Topples," American Scientist, Vol 94 (3) (May-June, 2006).
[113.] Antonis Rokas & Sean B. Carroll, "Bushes in the Tree of Life," PLoS Biology, Vol 4(11): 1899-1904 (Nov., 2006) (internal citations and figures omitted).
[116.] Neil A. Campbell, Jane B. Reece, Lawrence G. Mitchell, and Martha R. Taylor, Biology: Concepts and Connections, pg. 258 (4th ed., Benjamin Cummings, 2003) (emphasis added).
[117.] Id. at 278.
[118.] Neil A. Campbell & Jane B. Reece, Biology, pg. 429 (6th Ed., Benjamin Cummings, 2002).
[119.] Neil A. Campbell & Jane B. Reece, Biology, pg. 439 (7th Ed., Benjamin Cummings, 2005).
[120.] Cecie Starr, Biology: Concepts and Applications, pg. 238 (6th ed., Thomson Brooks/Cole, 2006) (emphasis added).
[121.] Kenneth R. Miller and Joseph S. Levine's Biology, pg., 373 (Prentice Hall, 2008) (emphasis added).
[122.] Scott Freeman, Biological Science, pg. 494 (2nd Ed., Pearson/Prentice Hall, 2005) (emphasis added).
[123.] Sylva S. Mader, Essentials of Biology, pg. 217 (McGraw Hill, 2007) (emphasis added).
[124.] Some textbooks include: Evolution: An Introduction by Stephen C. Stearns and Rolf F. Hoekstra (2nd Ed., Oxford University Press, 2005); Campbell, Reece, Mitchell, and Taylor, Biology: Concepts and Connections (4th ed., Benjamin Cummings, 2003); Kenneth Miller and Joseph Levine, Biology (Pearson / Prentice Hall, 2008); Collen Belk & Virginia Borden Maier, Biology: Science for Life, (Pearson / Benjamin Cummings, 2010); Cecie Starr, Biology: Concepts and Applications (Thompson Brook/Cole, 2006); Sylva S. Mader, Essentials of Biology (McGraw Hill, 2007); Glencoe's Biology: The Dynamics of Life (Florida Edition, 2006).
[124.] Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009) (emphasis added).