Flawed premise and dubious conclusion, but nice story
|
Well, it makes a great story. Peter Grant is a British evolutionary biologist who in appearance sounds like a cross between Charles Darwin and Rob Roy. His wife Rosemary wears Icelandic sweaters, Laura Ashley dresses and sandals. They have two daughters, Nicola and Thalia, and call each other darling. But for 20 years prior to the publication of this book the Grant family had been passing six months of each year on the Galapagos, on one of the most inaccessible and hostile islands, ostensibly to measure the beaks of many thousands of finches. But these aren't just any finches; these are Darwin's finches. They may have helped nurture the seeds of evolutionary thought in the great man's mind but he was not able, like the Grants, to study their variation over a protracted time. He saw them en passant and was so puzzled by the apparently random distribution of the species that he ignored them in the Origin of Species. It took the British biologist David Lack to begin the process of sorting out the effects of natural selection in determining niche specialisation among the different species eighty years later. Then along came the Grants.
So far, so good. Weiner's book is an interesting glimpse into the world of the field biologist and makes good reading. The research on Darwin's finches and its analysis is constantly being referred back to Darwin and his own theories. Unfortunately, the scientific premise is inaccurate. What the Grants have been meticulously observing over the years is not speeded-up evolution as Weiner claims but local adaptation in progress. Evolution requires novel genes, long periods of time and is irreversible. The process of speciation can happen relatively quickly with populations in isolation (cichlids in African lakes, tree snails on oceanic Pacific islands) but it still takes tens of thousands of years. What was happening on the Galapagos Islands over the twenty years of observation, as the numbers of big-billed and small-billed finches oscillated according to the availability of their specialised diets, was in effect a redistribution of gene frequencies, of genetic variation that was already present in the gene pool, in an attempt to adapt to changing conditions. It was not evolution in progress as claimed, but natural selection acting on environmental pressures. It is a good glimpse of how evolution comes about but what they were looking at were the results of evolution. In other words, it was the mechanism of evolution in progress rather than evolution itself. This misconception is the central premise of the book and continues to the end.
Having inundated the reader with pages on bill measurements - and to be fair it was an interesting insight into the nature and process of natural selection - the author spoils the effect with a confused final section which looks at many other examples of selective pressures, notably insecticide and antibiotic resistance. Once again he bangs on about how we can watch evolution in progress without stopping to think that myxamatosis-resistant rabbits (not an example the author uses but one that is familiar) are just that: rabbits that have developed a resistance to the myxamatosis virus. They have not evolved away from being rabbits into anything else. He then dangerously goes on to discuss cultural evolution. In a book for the layman a writer on evolution really should not stray into non-inheritable traits because the confusion of the two is a biological, social and racial minefield when extrapolated to humans. So, in inevitable and false conclusion, he states `...we have become the evolving animal. We are now evolving rapidly ourselves.' This is nonsense. The one thing we are not doing is evolving. For us that is all over. We will now be for all time Homo sapiens - even Jonathan Weiner.
|
|
Evolution for all
|
|
This is an excellent book I'd recommend it to anyone with even the slightest interest in biology, or evolution. It gives an excellent account of the Grant's work in the Galapagos islands on the finches that bear Darwin's name. As well as an apraisal and explanation of Darwin's thinking behind the theory of evolution. Highly recommended.
|
|
|
United States | 
United Kingdom | 
Canada