Back to index of science pages by Donald Sauter. So here goes. Getting through this one was a chore. I had to renew the book from the library twice - the maximum - and even then it went overdue before I could force myself to finish it and write up this report.

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Back to index of science pages by Donald Sauter. So here goes. Getting through this one was a chore. I had to renew the book from the library twice - the maximum - and even then it went overdue before I could force myself to finish it and write up this report.

If you expect to find any description or explanation of the evolution of new body parts, these pages will be a waste of your time. Don't expect to read of evidence - or speculation, even - of how the 13 Galapagos finch species got their different beak shapes. All of the so-called evolution which the author and the main characters gush over is limited to tiny shifts within the bounds of variations that already exist within a species.

Peter and Rosemary Grant and other members of their team have been making detailed observations of finches on one island in the Galapagos since The main measurements they take are dimensions of the finch beaks. They are very precise measurements, indeed: Page 5 "Beak length, Beak depth, 8. Beak width, 8 millimeters. As in all writings on evolution, it seems, you will find loads of ammo from the skeptics' camp.

Here are some passages early in the book; there are more further down. Page 6 The Origin Of Species says very little about the origin of species. Yet the book does not document the origin of a single species, or a single case of natural selection, or the preservation of one favored race in the struggle for life.

Page 7 Fossils argued that evolution has happened. Logic argued that natural selection can make it happen. But neither bones nor logic could demonstrate the one leading to the other, natural selection causing evolution. In , in an essay entitled "The All-Sufficiency of Natural Selection", the German biologist August Weismann confessed "that it is really very difficult to imagine this process of natural selection in its details ; and to this day it is impossible to demonstrate it in any one point.

Its action is neither rare nor slow. It leads to evolution daily and hourly, all around us, and we can watch. Page 16 With the conditions of life on this planet changing everywhere faster and faster, the pressures of natural selection are everywhere increasing in intensity, daily and hourly, even on islands as remote as the Galapagos.

Whether or not we choose to watch, evolution is shaping us all. Only one in 7 finches survived the drought, with more of the smaller finches getting killed off. The larger finches - with larger beaks - survived better. Their offspring also had larger beaks Natural selection! In Weiner's words: Page 78 And what made the difference between life and death was often "the slightest variation," an imperceptible difference in the size of the beak, just as Darwin's theory predicts.

Something tells me you'd get much the same result if you put human beings on a thousand mile forced march.

I'll bet you the offspring of the hardier humans who survived would have bigger noses. It had the opposite effect of the drought; the larger finches died. The explanation of why the big birds had a rough time with a superabundance of small seeds sounded strained to me. My mouth handles potatoes, and it handles rice grains, too. In any case, the net effect was to undo the effects of the drought.

The author enthuses: Page Not only can evolution push a species fast in one direction. Evolution can reverse directions and push it back just as swiftly.

As for me, I'm disappointed that we don't seem to be getting anywhere. Page The width of the [medium ground finch] beak That does not take [medium ground finches] back where they were at the start of the Grants' watch, but nearly so. The author unwittingly details another recent, major catastrophe in the lives of the finches. Page To find out what the [Galapagos] finches were eating, [American ornithologist Robert] Bowman shot them by the hundreds and inspected the contents of their stomachs.

But, no, there isn't a single word about how evolution responded that upheaval. Another instance of a major change for one of the finch species was a big decrease in the number of cacti. Page In spite of all this selection pressure [that is, diminished numbers of cacti], the cactus finches have not changed in the last ten years.

By all the Grants' measures, their beaks and bodies are the same now, on the average, as before the flood. This too makes sense in terms of the adaptive landscape, because in evolutionary terms these birds have nowhere to go. Very convenient It makes perfect sense when a species evolves in response to such changes; and it makes perfect sense when it doesn't.

Given the fuzziness of the notion of species in general, it's no surprise that there is some fuzziness as to whether the 13 Galapagos finch species are really separate species. The Grants have focused on the ground finches because they are easy to watch.

Three species of the ground finches are the large, medium and small ground finches. They have, respectively, large, medium and small beaks surprise! Page "Within each of these three species, the beaks of the individual birds are variable. Likewise, with the largest medium ground finches and the smallest large ground finches.

How they can tell themselves apart is a good question, one which the Grant team devoted some effort to. Still, the 13 species rarely interbreed. At least that was the case before the floods of For some reason, after the floods, there has been much more interbreeding. The extent of this hybridization caused a gear shift in the thinking of the finch watchers. Where natural selection had been the be-all-and-end-all up to that point, now they think hybridization is a big part of the evolutionary picture.

Page As [the Grants] contemplate the rise of the hybrid finches, they are beginning to suspect that selection and crossing [between existing species] work together as part of the same creative process. Besides giving the impression of another "theory du jour", this all remained a little unclear to me - partly because I wonder how you can have hybrids until you've developed different species or breeds in the first place.

In any case, it sounds like hybridization is undoing a lot of evolution: Page Roughly one out of ten birds born on [the island] now are hybrids, and the hybrids are doing better than any of the others on the island.

In a blink of evolutionary time, all of Darwin's finches could run together and congeal Again, it would have been a lot more fascinating to read about the appearance of new and fantastic finches on the island.

I liked this little typo: Page [Darwin's] vision had nothing to do with I think it can be claimed that the [Grant group's] work as a whole give the most detailed unified support to the Neo-Darwinian view of evolution that the theory has yet received.

As I've expressed elsewhere, it seems that evolutionists won't hang up a stationary target. He wondered why, if his thinking was right, we see any species at all. Why not a continuous spectrum from tiny individuals right on up the scale to kingdoms?

Why for instance do we find a vampire finch and a vegetarian finch? Why not a whole smooth series of omnivores between the two, with a perfect series of intermediate beaks? Why not a blur, a chaos, an infinite web Remember that there are those in talk.

Weiner explains it this way: Page 39 When we look around us Varieties in between them have died off and disappeared Does that work for you? There was a discussion page 91 of a study of the colorful spots on guppies. The guppy spots attract mates and predators. Over the course of generations the spots "evolve" to more or less gaudy depending on the type of predators around, and the mottling of the stream bed.

That's all very interesting, but I still wonder why Darwinism wouldn't give rise to a thousand other solutions. Why wouldn't females start to prefer the drabbest males? Why don't the males evolve shells, poisons, or killer teeth? There is a story page which seems to me another example of what I call the "ouija board" effect in science - an unconscious massaging of the data until it says what you want it to. Jamie Smith observed natural selection in song sparrows over a period of years.

He analyzed the data and concluded there was no evolution. But Dolph Schluter was determined to find evolution - and he did! Even though the birds ended up the same as when they started, he managed to find tiny variations year by year. Page Dolph says, "A species looks steady when you look at it over years - but when you actually get out the magnifying glass you see that it's wobbling constantly.

So I guess it's evolution in action. The world is not as stable as you think! Well into the book there is more ammo for the skeptics. I was more than a little surprised myself to see how badly Darwinism had fallen out of favor earlier in this century. Made me wonder if talk.

Page After Darwin's death, many biologists found it easy to accept evolution and impossible to accept Darwin's chief explanation for it. Evolution, yes; selection, no. William Bateson, the founder of modern genetics, wrote an elegy for Darwinism in , calling it "so inapplicable to the facts that we can only marvel At the time, however, it was an extremely stimulating suggestion.


The Beak of the Finch

Look Inside. Winner of the Pulitzer Prize Winner of the Los Angeles Times Book Prize On a desert island in the heart of the Galapagos archipelago, where Darwin received his first inklings of the theory of evolution, two scientists, Peter and Rosemary Grant, have spent twenty years proving that Darwin did not know the strength of his own theory. For among the finches of Daphne Major, natural selection is neither rare nor slow: it is taking place by the hour, and we can watch. With a new preface. It is the best exploration of evolution written in recent years. It conveys a powerful insight into life that helps us to understand the fundamental forces of nature and our relationship to the world about us. Highly recommended.


The Beak of the Finch: A Story of Evolution in Our Time

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