Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, August 21, 1994 TAG: 9408210111
SECTION: HORIZON PAGE: D-4 EDITION: METRO
SOURCE: Reviewed by LARRY SHIELD
DATELINE: LENGTH: Medium
During his journey through the Galapagos Islands on the Beagle, Charles Darwin noted in his diary that the finches present on the islands had no fear of man.
This was not an extraordinary observation as he also noted that all animals on the islands had no intrinsic fear of man. Being the scientist he was, Darwin collected specimens from both islands on the chain and thought little about them until he returned to England. As is common in the history of science, this seemingly insignificant incident buttressed what is arguably the most debated scientific theory in history.
Subtitled `A Story of Evolution in Our Time,` this well written, fascinating book shows how these few birds have given great support for Darwin's theories of evolution and natural selection. The book chronicles the 20-year work of Peter and Rosemary Grant who have observed and examined generations of finches found on Daphne Major, one of the smallest islands in the Galapagos chain.
The Grants have observed the small universe of finches during feast and famine, flood and drought, and watched natural selection modify the surviving birds to a physiognomy able to best adapt to current conditions.
When the conditions changed, so did the birds.
During times of feast and rain, large birds with small beaks were dominant. Small beaks were able to process the abundance of small diameter seeds available. As food became scarce, large birds with large beaks moved up the order as the large beaks are able to break the large, tough seeds which were untouched during times of plenty.
When the supply of large seeds dwindled, small finches with large beaks became dominant as they were able to better utilize the smaller amounts of food available. When food once again became available, small birds with small beaks dominated as they could better utilize the smaller seeds produced during flush times.
Not taking the millennia normally thought of by evolutionary scholars, these cycles have been documented by the Grants' in as little as 18 months.
This classic of science writing deserves to be as widely read as any Tom Clancy thriller. When the National Book Award for science is awarded, `The Beak of the Finch` must be considered, and, judging from previous year's awards, should win.
- Larry Shield trains dogs and horses in Franklin County.
by CNB