Excerpt from Chapter 6

Genesis and Genes is now available in Israel, the UK and the USA. It is expected in South Africa in January 2013. In the meantime, I intend to post a number of sample passages. Here is an excerpt from chapter 6.

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To round out the picture, let’s look at other claims made by evolutionary biologists in the context of ornithology. Two of Nature‘s “evolutionary gems” looked at birds. The first showcased Differential dispersal in wild birds. First the hype: the findings illustrate “the large effect of immigration on the evolution of local adaptations and on genetic population structure” and that “evolutionary differentiation can be rapid and can occur over surprisingly small spatial scales.” Don’t try too hard to look for the rapid, large evolutionary changes that were allegedly discovered. In one study we learn that females of the bird species Parus major (commonly known as the great tit) bred on the western end of the Dutch island of Vlieland tend to lay 1.15 eggs per clutch more than females bred in populations on the east end of the islands.

The other study cited by Nature also came complete with orotund declarations: we’re supposed to see “marked evolutionary differentiation” at “small spatial and temporal scales.” To wit, the journal informs its readers that over a span of about 35 years, great tits from the eastern part of the Wytham woodland in southern England saw a decrease in adult body size that amounted to a net average change of about 1 gram (less than 10 percent of total body mass). Fledgling birds likewise saw a small change in body mass. Birds in the northern part of the wood did not experience such a change.

Evolutionary biologist Keith Stewart Thomson wrote in 1997 that “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.” Before Darwin, the consensus was that species can vary only within certain limits. Centuries of artificial selection had seemingly demonstrated such limits experimentally. “Darwin had to show that the limits could be broken,” wrote Thomson, “[and] so do we.”[1] Call me phlegmatic, but neither the Galapagos finches nor the birds in Nature’s evolutionary-gems publication excite me as evidence for the non-teleological development of life in all its glory. The fact that, on average, one population lays one more egg per clutch than the other population is hardly a riveting discovery. Is this reason to believe that birds evolved in the first place – with fantastically complicated flight feathers; with highly specialised lungs adapted to process a high through-flow of oxygen; with a neurological system able to control the myriad aspects of flight; with the ability to lay eggs; and countless other adaptations? This is hardly the stuff that’s calculated to get the editor-in-chief of Nature rushing to the printing plant bellowing S-t-o-p the pre-ss!

One remarkable aspect of the evolution debate is that as the confidence of some evolutionary biologists leaks away in the face of remarkable new discoveries, bombastic announcements to the public continue unabated. So you can have Nature producing a document specifically targeted at the broad public and proclaiming that evolution is as well established as the fact that Earth orbits the Sun, while thoughtful biologists seriously question the dogma. Here is the opinion of evolutionary theoretician Armin Moczek:

“Given its importance and pervasiveness, the processes underlying evolutionary innovation are, however, remarkably poorly understood, which leaves us at a surprising conundrum: while biologists have made great progress over the past century and a half in understanding how existing traits diversify, we have made relatively little progress in understanding how novel traits come into being in the first place.” [Emphasis added].[2]

What Moczek considers a conundrum was understood by the average peasant before Darwin, and has only been consolidated by the evidence accumulated since then. Biology has made progress by describing and explaining specific processes, phenomena, pathways and events when you already have an organism. When you have a bird, with its myriad fantastically-complicated arrays of systems, the methodology of biologists is capable of shedding light on those processes that characterise the life and activities of the bird. They can tell us, too, about the limited flexibility of the bird’s genome. But trying to explain the origin of the bird using these same principles is to push the gates of credibility until the hinges scream.

References:

[1]: Keith Stewart Thomson, “Natural Selection and Evolution’s Smoking Gun,” American Scientist 85 (1997): 516-518.

[2]: Moczek, Armin. 2008. On the origins of novelty in development and evolution. BioEssays 30:432-47.

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