Darwin’s Finches demonstrate Natural Selection but not Evolution
When Charles Darwin arrived at the Galápagos Islands in 1835, he came across something evolutionists have been popularizing ever since. Certain finches had varying beak sizes; some small and some large. But Darwin had failed to realize the full significance of his find. Only until 1947 did David Lack popularize the finches as evidence for adaption and natural selection when he published a book on the matter.
After the 1977 drought at the islands, Peter and Rosemary Grant showed that finch beaks increased in depth by one half of a millimetre and attributed this to evolution. Peter Grant estimated in Scientific American that only 20 selection events like this would create a new species.But the finch beaks returned to their original size after heavy rains in 1982-83 caused more small seeds to grow. So there was no net change.
Also, Grant fallaciously extrapolated cyclical change into evolutionary change — something the National Academy of Sciences also did. But just because beak sizes grew one half of a millimetre, it does not mean they will continue to grow indefinitely until a new species forms! Indeed, the evidence shows the opposite — cyclical change is all that is observed. The beaks grow and they shrink intermittently.
So does all this demonstrate evolution in action? No; Darwin’s finches only show natural selection (something creationists agree with). As we should all know, natural selection is the‘tendency for animals better suited to their environment to survive and reproduce’. Since finches with small beaks aren’t good at cracking large nuts, islands with only large nuts will not have finches with small beaks.
Here is the main point: the potential for large and small beaks already exists in the population, just like the potential for short and tall people exists in the human population. All that happened was natural selection kept the better suited animals — it did not create anything new and no new genetic information was added. So we can conclude, despite the hype, that Darwin’s finches are a wonderful example of natural selection and variation, but not evolutionary change.
- Peter R. Grant, “Natural Selection and Darwin’s Finches,” Scientific American 265:82-87, October 1991. Back to text
- H. Lisle Gibbs and Peter R. Grant, “Oscillating selection on Darwin’s Finches,” Nature327:511-513, 1987. Back to text
- Science and Creationism: A View from the National Academy of Sciences, Second Edition (Washington, DC: National Academy of Sciences Press, 1999), Chapter “Evidence Supporting Biological Evolution,” p.2. Back to text