Sunday, May 22, 2011

Junk & Jonathan: Part 4—Chapter 1

I received a copy of the book a few days ago and this is my first posting on its contents. For a list of other postings on this topic see the link to Genomes & Junk DNA in the "theme box" below or in the sidebar under "Themes."

This is a very small book. There's only 114 pages of text—it's more like a large pamphlet than a book. If I'd read it from front to back in one sitting it would only have taken an hour or so. But I couldn't read it in one go because nobody can put up with IDiot rhetoric for that long!

Chapter 1 is The Controversy over Darwinian Evolution. It has nothing to do with junk DNA.

Wells begins by telling his readers that evolution is a fact. By that he means "microevolution." Wells doesn't believe in macroevolution or common descent and he even challenges the evidence for speciation. As usual, he supports his claims with selected quotations from scientists.
Sixty year after Dobzansky wrote this, biologists had still not observed the origin of a new species ("speciation") by natural selection. In 1997, evolutionary biologist Keith Stewart Thomson wrote: "A matter of unfinished business for biologists is the identification of evolution's smoking gun," and "the smoking gun of evolution is speciation, not local adaptation and differentiation of populations."
Wells is telling his readers that as long as biologists have not directly observed a new species forming then speciation has not been demonstrated. This rules out all evidence from the fossil record and all evidence from molecular phylogeny. Nice trick.

Problem is, there's lots of lots of evidence for speciation, including some examples where speciation has been caught in the act. Wells, like most IDiots, doesn't understand how evolution works. He seems to think that new species will form overnight and that all biologist have to do is keep their eyes open and record the examples.

I don't know for sure whether Wells intends to emphasize speciation by natural selection when he claims that, "biologists had still not observed the origin of a new species ("speciation") by natural selection." If that's his intent then it's true that there are very few examples of true speciation (biological species concept) that can be attributed directly to natural selection. As Jerry Coyne points out, reproductive isolation is mostly due to accident (random genetic drift) and not natural selection [The Cause of Speciation]. That's in line with modern evolutionary theory and Coyne should know because he's one of the world's leading experts on speciation. [UPDATE: Coyne and some commenters have corrected me. Coyne actually does think that most speciation is due to natural selection. I'll stick with Futuyma as my authority. He's much more open to the idea of speciation by random genetic drift (Evolution 2nd ed. p. 447)]

There are two possibilities here. Either Wells is deliberately misleading his readers by emphasizing that speciation must occur by natural selection or he's ignorant of modern evolutionary theory. Since most IDiots have a concept of evolution that dates back to the nineteenth century, I'll go with the second explanation. However, there's almost certainly an element of deception in his remarks since Jonathan Wells has a long history of deliberately misrepresenting evolution.

Theme

Genomes
& Junk DNA
So, Wells is dead wrong about the first point in his book. There's abundant evidence of speciation (and macroevolution) and, furthermore, modern evolutionary theory does not attribute speciation exclusively to adaptation (i.e. there's more to evolution than Darwinism).

The importance of Wells' rejection of macroevolution will become obvious later on in the book when he argues that Intelligent Design Creationism does not rule out common ancestry. He agrees that someone like Michael Behe can believe in common descent and still be a card-carrying IDiot.

By the way, Wells is clever enough to cover his bases in case speciation is ever observed.
Of course, even if scientists eventually observe the origin of a new species by natural selection, the observation would not mean that natural selection can also explain the origin of significantly new organs or body plans. But the fact that scientists have not observed even the first step in macroevolution means that "evolution's smoking gun" is still missing.
The rest of the chapter (three pages) is a re-hash of arguments Wells made in Icons of Evolution and elsewhere.
  • The Cambrian Explosion "contradicts Darwin's theory that major differences should arise only after millions of years of evolution ...."
  • Molecular evolution isn't accurate: "molecular evidence is plagued with inconsistencies." The rejection of molecular evidence as unreliable is going to cause problems for Wells later on since he relies on it for some of his arguments about junk DNA. As usual, the IDiots want to have their cake and eat it too.
  • Homology is a circular argument, according to Wells, so you can't use homology as evidence for evolution. That's correct. Similarity is the evidence and homology is the conclusion. This flaw in Wells' reasoning has been pointed out to him repeatedly over the past decade but he ignores all criticism and continues to use arguments that have been refuted.
  • The Haeckel drawings were fakes and, "The truth is that vertebrate embryos start out looking very different from each other, then they converge somewhat in appearance midway through development before diverging as they mature." This has nothing to do with junk DNA so I won't discuss the massive amount of embryological evidence for evolution.
Wells closes with,
So microevolution is a fact, supported by overwhelming evidence, but macroevolution remains an assumption, illustrated with icons that misrepresent the evidence or rely on circular reasoning. The icons are not science, but myth.
This sets the tone for the rest of the book. Even though it is filled with references to the scientific literature there's never any discussion of alternative hypotheses or conflicting data. This is not a book where the author wants to inform his readers about the exciting controversies and conflicts within science. This is a book where the author wants to promote creationism by attacking and misrepresenting evolution using faulty logic and untruths.

The next paragraph is quite interesting. He invokes the beliefs of Americans as support for his claims. Apparently they're much more perceptive that the typical evolutionary biologist. (I wonder what he thinks of Australians and Europeans?)
This may be one reason why—despite the Darwinists' near-monopoly over science education—most Americans still reject the doctrine that human beings evolved from ape-like ancestors by unguided processes such as random variation and survival of the fittest.
I think this means that Wells also rejects common ancestry. If so, it will mean that he can't use it to support any of his arguments later on in the book, right?

Finally, at the very end of the chapter we get to the point,
In the 1950s, neo-Darwinists equated genes with DNA sequences and assumed that their biological significance lay in the proteins the encoded. But when molecular biologists discovered in the 1970s that most of our DNA does not code for proteins, neo-Darwinists called non-protein-coding DNA "junk" and attributed it to molecular accidents that have accumulated in the course of evolution. Like peppered moths, Galapagos finches, Darwin's Tree of Life, homology in vertebrate limbs, and Haeckel's embryos, "junk DNA" has become an icon of evolution. But is it science of myth?
I've discussed Wells' ignorance of history in previous postings but, for the record, here are the facts.
  • By the 1970s molecular biologist were well aware of the fact that non-protein coding genes existed (e.g. ribosomal RNA genes, tRNA genes etc.)
  • By the 1970s molecular biologists knew of several functions of DNA sequences that weren't genes. Origins of replication and regulatory sequences were well-known but there were others.
  • Even in the 1970s no knowledgeable molecular biologist could ever defend the idea that all non-coding DNA was junk. (It's true that there were some stupid scientists who weren't aware of tRNA genes and regulatory sequences and made silly statement because of their ignorance but they don't count.)
  • By the 1970s junk DNA was a fact. The scientific controversy was over how much of our genome is junk. Is it the majority or only a small percentage?
  • By the 1970s knowledgeable evolutionary biologists were well aware of the fact that most of our genome was mutating and evolving as though most changes were neutral (genetic load arguments). This didn't mean that most of our genome was junk but it did mean that the sequence couldn't be important or we would never be able to tolerate the genetic load. This was not common knowledge among biologists—still isn't.
  • By the 1970s most molecular biologists were aware of the so-called "C-value paradox" where very closely related species have very different genome sizes. They correctly interpreted this to mean that the species with the large genomes probably didn't need all that extra DNA. (Up until now, Intelligent Design Creationists have not offered a reasonable answer to The Onion Test. Wells tries on Chapter 8.)
  • The proponents of large amounts of junk DNA in our genome would hardly ever have referred to themselves as "Darwinist" or "neo-Darwinists." In fact, they tended to be among those evolutionary biologists who opposed adaptationism and favored Neutral Theory and random genetic drift. Pluralist concepts were much more compatible with the idea of significant amounts of junk DNA than strict "Darwinist" interpretations of genome evolution.


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