Flatfish Evolution Revealed 07/11/2008 July 11, 2008 — Darwin has been vindicated again, to hear the media reports. Science Daily said, “Flatfish Fossils Fill in Evolutionary Missing Link.” National Geographic News ruled out the competition by saying, “Odd Fish Find Contradicts Intelligent Design Argument.” In a nutshell, Science Daily said, “Hidden away in museums for more that 100 years, some recently rediscovered flatfish fossils have filled a puzzling gap in the story of evolution and answered a question that initially stumped even Charles Darwin.” By implication, anything that would stump Darwin would stump all the brightest minds in history. The case concerns two species of flatfish fossils from Italy, locked in away a French museum, that were re-evaluated by Matt Friedman (U of Chicago and Chicago Field Museum). In his report in Nature,1 he claims that the fossils clearly show mature forms of flatfish with eyes only partially migrated to the top. That’s the transitional-form claim. He also claimed they were the right age to precede the later flatfish with fully migrated eyes. Then he speculated on how the partially-migrated eyes might have been adaptive to the fish. That’s the thing that puzzled Darwin. Apparently, Darwin was tempted to resort to Lamarckian mechanisms to explain it. Not necessary, Friedman explained: “The discovery of stem flatfishes with incomplete orbital migration refutes these claims and demonstrates that the assembly of the flatfish bodyplan occurred in a gradual, stepwise fashion,” he said. “Thus, the evolutionary origin of flatfish asymmetry resembles its developmental origin, with increasing degrees of orbital migration transforming a symmetrical precursor into a fully asymmetrical form.” Friedman is not resurrecting Haeckel’s idea that “ontology recapitulates phylogeny,” is he? Friedman noted that modern flatfish sometimes prop their bodies up using their fins. This might have allowed the half-evolved forms to use both eyes, he speculated. It’s not clear why this would be beneficial to a fish. It would seem a lot of work for an upright fish to lie on its side with one eye up, occasionally struggling to get its other eye up for a better look. The flatfish-to-be would certainly not be able to look ahead to the day, perhaps hundreds of thousands or millions of years in the future, when its descendents would get both eyes to the top and life would be sweet. And why do living flatfish exhibit this behavior when both eyes are already on top? Whether or not this makes any evolutionary sense, the bulk of Friedman’s argument that the alleged transitional forms were adaptive was that they existed. This begs the question that existence proves adaptation – let alone a process of evolution. How could one know that extinct life forms were not maladapted? Maybe that is why some went extinct. It does not necessarily prove they were evolving toward a more adapted state. Some damaging admissions about the evolutionary story showed up in the final paragraph – after the pro-Darwin claims had been made.
Inferring interrelationships between higher groups in this explosive radiation has proved difficult, and an unresolved bush persists. Documenting the origin of these clades is vital to understanding the roots of modern biodiversity, because acanthomorph fishes comprise nearly one-third of living vertebrate species. Stem representatives—such as Amphistium and Heteronectes [the two fossils discussed in the paper] in the case of pleuronectiforms [flatfish]—have yet to be identified for many acanthomorph clades, but their recognition might prove invaluable in delivering a stable hypothesis of interrelationships for this exceptional vertebrate radiation.
What this seems to imply is that this “transitional form” is too little too late. Why have these fossils been sitting in museums for 100 years, only now to be reclassified as missing links? And where are the missing links for the numerous other acanthomorph fishes (1/3 of all living vertebrates), that so far as is known at this time, comprise an “unresolved bush” instead of a phylogenetic tree? Did not Darwin envision a gradually branching tree, not a picture of “explosive radiation”? According to Friedman, the bulk of missing links are in the future. It will be up to future biologists to find them. He implied there is not now, nor ever has been, a “stable hypothesis of interrelationships” about vertebrate evolution. This can only mean that the current evolutionary story is unstable. Admitting an “exceptional vertebrate radiation” undermines a natural law of evolution. It’s an exception, not an instance. In addition, Friedman admitted to the National Geographic reporter that “Fossils from excavations in northern Italy and Paris revealed that the intermediate specimens once lived together with flatfishes having both eyes on one side of the skull.” The ancestor and descendent lived side by side. Doesn’t that make it a little questionable to conclude an ancestral relationship? His assertion that these two fossils with partially-migrated eyes demonstrate that “the assembly of the flatfish bodyplan occurred in a gradual, stepwise fashion” seems exaggerated – to say nothing of the claim it vindicates Darwinism. The National Geographic write-up took the unusual step of asking the opinion of a creationist. After opening with a line that the discovery of this missing link “could give intelligent design advocates a sinking feeling,” and stating without a reference that “Intelligent design advocates have seized on the idea of instant flatfish rearrangement as evidence of God or another higher being intentionally creating new animal forms,” NG asked Frank Sherwin of ICR for his response.2 The query was preceded by the qualifier, “The new discovery, however, is unlikely to change the minds of many creationists.” Sure enough, Sherwin found the evidence “underwhelming.” He did not deny that rearrangements of parts was possible within created kinds. “What we’re asking is, Show me how a fish came from a nonfish ancestor.” After all, the putative flatfish ancestor and its sole descendents already had eyes, fins, gills, scales and all the equipment of a fish. Moreover, flatfish and upright fish have the same vertebrate body plan. The parts only got rearranged, if they “evolved” in a Darwinian sense. Though the rearrangement seems to help the flatfish with its camouflage, obviously most fish get by just fine without flatness. It could not be argued, therefore, without floundering for the halibut, that the environment pushed fish to adopt this posture. Interesting facts about flatfish were stated in the NG article. There are 500 species with this lifestyle. They vary from four inches to seven feet in size. Surprisingly, the fish are not born that way. The embryonic fish start out life with eyes on both sides of the skull, as with normal fish. “As a flatfish develops from a larva to a juvenile, one eye migrates up and over the top of the head, coming to rest in its adult position on the opposite side of the skull.” The young adults apparently have to spend some time learning to cope with this biological rearrangement that takes place as they grow up. Biologist Richard Palmer (U of Alberta) confessed that the mystery of flatfish development has “really been a major, major puzzle to evolutionary biologists.” Has it been resolved? The answer must be evaluated in context of Friedman’s own admission that the big picture of acanthomorph fish evolution remains unresolved and current theories are unstable. Evolution News, meanwhile, exposed numerous inaccuracies in the National Geographic write-up. Despite the empirical doubtfulness of the claims, evolutionists seem in ecstasy with the spirit of Darwin. Philippe Janvier, in the same issue of Nature,3 could not resist eloquence: “In the case of the fossils described by Friedman ... one cannot but admire the vindication of a prediction, made by Darwin, of a gradual eye migration during flatfish evolution that mirrors the metamorphosis of the living forms.” Janvier is not resurrecting Haeckel’s idea that “ontology recapitulates phylogeny,” is he? Evolution in action: it’s all over the place, claimed Jonathan Weiner of Natural History Magazine. Writing for Live Science, he said, “Finches, monkeyflowers, sockeye salmon, and bacteria are changing before our eyes.” He launched into a paean of praise for Darwin’s gradualism against a backdrop of his wife Emma’s religious concern for his soul. “For most of the twentieth century the only well-known example of evolution in action was the case of peppered moths in industrial England,” he said. He may have revealed more than he wished about the state of evolutionary theory. Did he really intend to suggest that during a whole century, with the Scopes Trial and all the propaganda of the Darwin Centennial, only shifting populations of one species of moth provided a well-known example of evolution in action? Undoubtedly he will be happy to add the flatfish story to the score. He needs to show the other side of America’s “house divided” over evolution that by “peering over the shoulders of biologists,” one can “actually watch Darwin’s process in action.”
1. Matt Friedman, “The evolutionary origin of flatfish asymmetry,” Nature 454, 209-212 (10 July 2008) | doi:10.1038/nature07108. 2. Sherwin is a Biblical creationist, not a member of the intelligent design community per se, although he would accept some of their principles. 3. Philippe Janvier, “Palaeontology: Squint of the fossil flatfish,” Nature 454, 169-170 (10 July 2008) | doi:10.1038/454169a.
We peer over the shoulders of biologists all the time and find them exaggerating. They talk about evolution in action, but what is observed is evolution inaction (01/01/2007). They need to get busy and find the vast majority of missing links they claim must exist if they expect reasonable people to accept their myth. Finding explosive radiations and unresolved bushes is only helping their sworn enemies, the creationists. No wonder this discovery is “unlikely to change the minds of many creationists.” They have too much respect for evidence and logic. To watch Darwin’s process in action – you mean his propensity for just-so storytelling? Why yes, we see that very clearly. One of our readers asked a good question. How do we know that these fossils were not mutants, or were not de-evolving from flatfish back to the upright position? After all, blind cave fish can re-evolve eyes under the right circumstances (see 01/08/2008). Maybe in these rare cases the developmental process got stopped in the middle. If the proposed intermediate and the full flatfish lived side by side, it seems these possibilities are just as warranted by the evidence. Even if an independent panel of philosophers and logicians were to judge that the evidence in this paper is sufficient to justify the claims that the fossils were (1) ancestral and (2) intermediate and (3) adaptive (conclusions one should not assume based on the exaggerated claims of its supporters), creationists can handle a few rearrangements of existing parts without a whelm. Sherwin is right about the real issue: “Show me how a fish came from a nonfish ancestor.” That goes for the entire panoply of life. Show us how a human came from a bacterial ancestor. Systematic gaps, explosive radiations and uresolved bushes put the burden on the evolutionists, not the creationists. Stop the BAD science (bluffing assertions of dogmatism). Get back to the intellectual restraint that scientists are supposed to exhibit.