To Olley and Rubinstein
Over on the Social Affairs Unit page there is a post by a Dr. Rubinstein that takes evolution to task using a selection of arguments from the antievolutionist ensemble of arguments. There have been a number of, ahem, abrupt disagreements with Rubinstein posted on that blog. A Dr. Olley (who I unfortunately referred to as “Dr. Oller” there) took some exception to the tone of the responses and suggested that the theory of evolution was not “intuitive” and suggested some historical reflection for people. I left aside problems in Olley’s text in my response to him, taking up Rubinstein’s arguments.
Dr. Olley,
It is a certainty that the tone of the discussion could be improved. So, perhaps a review of the evidence concerning Dr. Rubinstein’s claims would be in order. Was Rubinstein right or wrong in what he wrote?
Is common sense a guide to scientific accuracy? I would think not. To point out an example that does not have to do with the current topic, consider quantum mechanics and such counterintuitive items as the two-slit experiment.
Are there a growing number of doubting scientifically trained commentators? Actually, this claim of Rubinstein’s is ill-formed. One could have a point of view whose “market share” in the marketplace of ideas was monotonically decreasing while the absolute numbers of people involved was increasing. The interesting fact about the claim that “more and more” scientists are doubting the theory of evolution is that it predates Darwin’s Origin of Species and comes close to predating Darwin himself. See Glenn Morton’s essay for the details. Surely it is an odd sort of movement which has been continuously growing a century and three-quarters and yet still only incorporates a tiny fraction of the scientific community?
What of the claim that scientists have “failed to challenge” evolution? I direct your attention to Peter Bowler’s “Evolution: The History of an Idea”, in which the author describes a substantial number of theories in evolutionary biology which were proposed, challenged by scientists, and discarded as being at odds with the evidence.
Certainly Niles Eldredge and Stepehen Jay Gould considered punctuated equilibria to be a challenge to the view of “phyletic gradualism”, and I do not recall anyone calling either of them a “creationist”. A witticism comes to mind, but since the topic was a kinder, gentler exchange I will forego using it.
I want to quote Rubinstein here… “Nevertheless, there are so many deep implausibilities in the Theory of Evolution as it is commonly understood that it seems to me, as a non-scientist, that something must surely be radically wrong.” This is something upon which I can wholeheartedly agree with Rubinstein. The common understanding of evolution is, as is demonstrated by Rubinstein’s further text, composed of common misunderstandings of evolution. Certainly a part of what is wrong is the lack of effective education in this regard.
The claim that “evolution is impossible” and that speciation cannot happen is simply at odds with the scientific literature. See also the FAQs on observed speciation, more speciation events, and common descent. Beyond the insistence of evolution-deniers upon videotaped species transitions, there is an absolutely huge chunk of scientific literature on the topics of incipient speciation and analysis of reproductive isolating mechanisms. As for when one figures out that speciation has occurred, there can be difficulties, as in the cryptic speciation of populations of Cordylochernes scorpioides which look alike, but have genetically diverged such that there is postzygotic reproductive isolation. That sort of situation means that the number of speciation events that are observed in the next few years may be a serious underestimate of the true number of speciations that take place. Another point to be taken is that we can hardly be said to have a handle on knowing what species are in existence right now. The knowledge of populations in regions like the Amazon basin is still pretty sketchy, and yet there is immense biodiversity there (or was, given the habitat loss going on there).
When Rubinstein says that no one expects evolution to occur, he apparently means people who are not biologists and who are not looking at populations in nature. For biologists, though, the view is different. From studies of guppies in tropical streams to finches in the Galapagos to peppered moths to anolis lizards on Caribbean islands, researchers are doing work on characterizing the evolution that does, in fact, happen. Medical researchers are keenly aware of the expectation of evolution in HIV virus strains, and even forensic investigators have used that evolution in their casework. Agricultural researchers deal with evolutionary processes, too, in trying to reduce problems with pests and disease in crops and livestock.
Rubinstein then returns to speciation, and claims that no one has seen one species give rise to another in one generation. This would be a saltational change, and is something that Darwin thought did not happen. Biology is such a confounder of neat principles, though, that biologists have been privileged to see or detect saltational speciation. This is a pretty common occurrence in certain plant taxa, such as orchids. Consult the American Orchid Society list of species and note how many of those say “tetraploid”. Each one is an existence proof to throw light on Dr. Rubinstein’s essential ignorance of the topic. My genetics professor of many years back, Dr. Wallbrunn, was particularly interested in those tetraploid orchid species. Tetraploidy is known to have happened within animal species, too. Consider Hyla versicolor, a tetraploid daughter species of Hyla chrysoscelis. There are systems of differing ploidy in lizards to make your head spin. Speciation in mammals via differing karyotypy is something suggested by the evidence in the Suidae. That would likely take two or three generations to accomplish, but still comes pretty close to Rubinstein’s demand for existing saltation to liven up more staid means of achieving speciation.
The claim that most examples of evolution are “highly dubious” doesn’t stand up to scrutiny. Peppered moths were never claimed to have speciated. The point at issue in that research was whether it was a case of natural selection acting on a population. That’s a different issue than speciation. And those researchers who actually work on peppered moths are quite clear that natural selection has been at work there. Please see Alan Gishlick’s essay on the antievolution objections to peppered moth research.
Rubinstein claims that fossil evidence is arguable or “logically fallacious”. While it certainly is the case that one usually cannot tell from a fossil whether it had offspring and produce a pedigree, one doesn’t see antievolutionists taking this objection to its logical reductio ad absurdum conclusion and say that each foram in the white cliffs of Dover was a special creation of God thereby. While Rubinstein dismisses the fossil record for horse evolution, actual paleontologists say differently. Niles Eldredge says that the fossils are all found in the geologic record just as predicted by evolution in the correct temporal order, and says that these fossils are “every creationist’s nightmare” (see his “Triumph of Evolution” around page 130 for the discussion). Bruce McFadden is a paleontolgist who has specialized in fossil horses (and was also one of my professors a long time ago). His take is the same, that the horse fossil record is a brilliant illustration of historical evolution.
When antievolutionists, and Dr. Rubinstein, claim that there are no transitional fossil sequences, I point them to a gradual and sympatric divergence in foraminifera and ask them to give their technical reasons for saying that that doesn’t count as a transitional sequence. Dr. Rubinstein’s objection falls into a category of responses that I call “non-evidentiary response items” or NERI. The neat thing about issuing a NERI is that one is relieved of the burden of actually looking at the evidence and making an effort to understand what one is looking at. The evidence is completely irrelevant to a NERI, which makes it easy to figure out whether someone is deploying one. If different evidence would not change the effectiveness of the argument, it is a NERI. Does it matter exactly what those horse fossils are to Rubinstein’s argument? No, of course not. However, paleontologists have yet to be convinced of the superiority of simply stating a NERI as opposed to actually studying fossils and making inferences from what one finds there. I’m sorry, I seem to have let some rhetorical content slip into this response. As to the number of expected transitions, I made an estimate based on Charles Darwin’s famous passage and came up with a number fully in accord with what we see today. If Dr. Rubinstein would care to turn his assertion into a quantitative form, we could then compare the two. I find it interesting that Rubinstein relies on Corliss as a source for a grand sweeping negative claim. Botany is not my field, so I will check on that.
Rubinstein repeats the old antievolution claim about organs needing to appear all at once and be integrated into systems. Eyes are certainly interesting examples, coming, as it were, in all forms of differing complexity from simple patches of light-senstive material through “cup” eyes to closed camera-style eyes. Even within a morphological form, one can find examples of differing structure, as in the differences between camera eyes in mammals and those in squid. Evolutionary biology does not hold that an organ like the eye has to appear “all at once”. The critique as given by Rubinstein is an indictment of creationism, not evolution. Evolution posits that new organs are derived from existing organs. Rather than the eye, which is generally soft tissue and unlikely to fossilize, consider the mammalian middle ear and its three-bone impedance matching system. If any of those parts is missing, impedance is not matched and in humans that results in about a 30dB reduction in hearing senstivity. But there is a good fossil record of stages in the development of the mammalian middle ear showing that the middle ear did not “poof” into existence somewhere along the way, but rather was the result of a process that took millions of years in incremental steps.
Rubinstein has a certain fascination for the phrase “survival of the fittest”. There is a historical connection to evolutionary biology, to be sure, but no evolutionary biologist nowadays considers it as anything but historical trivia, and certainly not a regulative principle in evolutionary theory. The role of contingency in historical evolution is widely appreciated in evolutionary biology. Others have already commented on the gap between Rubinstein’s description of ecology and what actually obtains.
Rubinstein’s claim that increasing complexity requires a “guiding hand” is noticeable for the complete lack of scientific research cited in its support. The assertion that “saltation” has any part in “punctuated equilibria” would come as a surprise to Gould, Eldredge, or even Ernst Mayr, whose theory of allopatric speciation forms the basis of PE. Allopatric speciation has nothing to do with saltation. The notion that something does or does not accord with the facts, coolly considered, implies that the person making the decision has actually taken the time to look at “the facts”. It is by no means apparent that Dr. Rubinstein has taken the time to acquaint himself with a sufficient sampling of biological facts to make pronouncements within that field.
