Two Local Events
The end of the summer holidays and the beginning of the school year create busy schedules with other activities filling in as well. And this year is not an exception. This coming week, for example, there will be two important meetings. On Wednesday at 7:00 p.m., Princeton University biologists Peter and Rosemary Grant will deliver the Vaughan Lecture at the Buffalo Museum of Science and on Saturday beginning at 9:45 a.m. a program at Times Beach will honor four local conservationists who fought for years to make that sanctuary possible.
Ten years ago I wrote about the book The Beak of the Finch: A Story of Evolution in Our Times by Jonathan Weiner. The following year it was awarded a Pulitzer Prize. Weiner's book is about the work of the Grants with birds often designated "Darwin's finches" over many years on the barren island of Daphne Major. That tiny uninhabited volcano peak is in the Pacific Ocean Galapagos archipelago off the west coast of Ecuador.
Many readers will recognize those finches for their contribution to Charles Darwin's thinking about evolution, thinking that finally led to his 1859 paradigm shifting On the Origin of Species. Darwin collected many of these finches when he visited the Galapagos in September 1835 on his world circumnavigation aboard HMS Beagle. The birds differed markedly in their characteristics. For example, some had thick bills like grosbeaks, others thin bills like warblers. He and later observers named 14 apparent species, among them warbler finch, woodpecker finch, cactus finch, ground finch and large tree finch.
Upon his return to England Darwin turned over his collections on the Beagle voyage to the Geological Society of London and the birds went to the famous British ornithologist, John Gould. Gould came to the unexpected conclusion that the finches were not as unrelated as their appearance led people to believe; rather, they belonged to a closely related group, new to mankind and apparently derived from a common ancestor. (Sibley and Ahlquist later used DNA evidence to associate these birds closely with our North American tanagers.) This unexpected relationship among birds that differed so strikingly from island to island in the Galapagos chain served as one more factor in Darwin's rethinking of the then generally accepted concept of fixed species.
But even the vast majority of scientists who believe in evolution consider it as taking place over millennia, hundreds of thousands of years. We may accept that we are related to apes but we don't think our great grandparents were apes.
It was this central idea that motivated the Grants' research. They trapped, marked and measured the finches on their tiny island over a period of 25 years.
Among other things, they documented the results of a 551 day period when the island received no rain whatsoever. As a result of this drought, plants withered and the tiny seeds which served as food for medium ground finches became scarce. Now bill size became important. The individuals of that species with larger bills could find alternate food sources, because their bills would crack open tougher seeds. Their nest mates with smaller bills were out of luck and died of starvation.
How, the Grants asked themselves, would this be reflected in subsequent generations of medium ground finches? And here is where their detailed measurements paid off. They compared measurements of birds before the drought with their grandchildren after it and found a difference of 3-4%. They had documented a small wobble in inheritance that represented natural selection in action.
Their work has won the Grants a series of awards: the Darwin Medal (2002), the Balzan Prize (2005), the Darwin and Wallace Medal (2008) and the Kyoto Prize (2009).
The Saturday Times Beach commemoration will honor four conservationists who fought through political inertia and Byzantine regulations over many years to lead to the protection and development of this important final passerine bird stop-over on Lake Erie before spring migrants reach urban Buffalo. These members of the Friends of Times Beach Nature Preserve are Robert Andrle, Paul MacClennan, George Arthur and Mike Hamilton.-- Gerry Rising