Posted by Carlos on April 23, 1998 at 11:23:51:
"The Beak of the Finch" by Jonathan Weiner (which I acquired and read because of the review on rpcman’s site) is largely an account of the work of Peter and Rosemary Grant, who have been studying finches in the Galapagos Islands since 1973. Darwin studied these finches during his travels, and wrote about them in "Origin of the Species".
The finch population of the Galapagos is perfect for a study of evolution in action because of the limited number of species and the closed nature of the ecosystem (since the one island where they focused most of their study is quite isolated).
The Grants have studied over 20 generations of finches, many thousands of individual birds. They caught virtually every bird, measured them and kept track of their progeny. The result is an empirical account of evolution in action. The inescapable conclusions from their work include: (1) evolution by natural selection does occur; (2) natural selection can occur at a much faster pace than most people realize; (3) we have a much better understanding of how speciation (the creation of new species) can occur (although the Grants did not observe this directly).
Weiner also discusses efforts by others to document evolution occurring in fish populations, where speciation was actually observed.
The last part of the book discusses evolution by natural selection among bacteria and viruses. Anyone who follows the news is aware of the emergence of resistant strains of bacteria. Many don’t understand how they become resistant - through natural selection. A given antibiotic may kill 99% of a bacteria, but because of mutations and subtle differences among the bacteria some will survive. Also, bacteria under stress (under attack by antibiotics) literally open their cell walls to envelope plasmids (strands of DNA) from other bacteria or even viruses in an attempt to survive. Sometimes those attempts are successful, and resistant strains of bacteria are born. Those strains become dominant and spread through society, and soon we can’t kill bacterial infections with certain antibiotics anymore. The same example can be made with insects and pesticides.
We frequently hear arguments from people who don’t "believe" in evolution. That is utter nonsense. The theory of evolution has been as rigorously proven as any scientific theory. Whether you believe in it or not, it is happening right now all around you.