The Joseph Grinnell Medal 2005

On August 31st 2005, Peter and Rosemary Grant were awarded the Joseph Grinnell Medal, and gave the Joseph Grinnell Memorial Address at 5 PM in 1 LeConte Hall on the Berkeley campus. The public was invited to this free lecture, the title of which is “Evolution of Darwin’s Finches”(see abstract below).

The Joseph Grinnell Medal was instituted in 1983 to memorialize the original director of the Museum of Vertebrate Zoology. In his tenure, Joseph Grinnell established a scientific ethos that demanded the highest standards of field, laboratory and museum research in the natural history of vertebrates. His model was both flexible and progressive, and under his leadership the MVZ flourished and grew to become one of the foremost university-based natural history museums in the world. Grinnell’s goal was not simply to build a collection of specimens, but to design an institution focused on an understanding of vertebrate communities – a museum that would be a storehouse of facts relating organisms, environments, and evolution. These resilient founding principles have continued to provide guidance throughout the history of the Museum. In addition to being a systematist, Grinnell was a founder of what is now called Evolutionary Ecology, and he is widely credited with the development of the ecological niche concept.

Every five years, the faculty of the Museum elects a recipient of the Joseph Grinnell Medal, based on career-long work in the field of vertebrate natural history with an emphasis on evolutionary ecology. Past winners included George Bartholomew, James Brown and David Wake. This year we honor two evolutionary biologists, Peter Grant and Rosemary Grant. Their work on Darwin’s Finches in the Galápagos Islands, spanning over three decades, enabled them to quantify and demonstrate evolutionary adaptations in “real-time” (as short as a single generation). Their meticulous recording of complete life-histories and morphometrics of virtually every Geospiza finch on one of the islands have shed significant light on some evolutionary debates. Specifically, the debates that parse the relative importance of genetic variation, behavior, and learning as factors in the formation of reproductive barriers to gene flow between closely related sympatric species, and whether or not speciation can occur in sympatry.


Joseph Grinnell Memorial Address for 2005
Evolution of Darwin’s Finches

Abstract: The problem of explaining the origin of species has remained with us since Darwin’s time. There is no shortage of ideas about how speciation occurs, but there is a lack of empirical information from nature that can be used to distinguish between alternative mechanisms. A fruitful source of information is the adaptive radiation of certain groups of organisms, especially those that have diversified relatively rapidly and recently and continue to occupy the environment in which they evolved. In this lecture I will discuss the findings from long-term research into the biology of populations of Darwin’s finches on the Galápagos islands. Fourteen species have been derived from a common ancestor in the last two to three million years, none has become extinct as a result of human activities and part of their environment is still in a natural state. I will discuss the ecological factors promoting diversification, how evolution occurs when the environment changes, what the barriers are to interbreeding, how they are inherited and what happens when they break down.

Learn more about Peter Grant.
Learn more about Rosemary Grant.