Peter and Rosemary Grant

Peter R. Grant and B. Rosemary Grant, a married couple, are both evolutionary biologists at Princeton University. They are noted for their work on Darwin's Finches on the Galapagos Island named Daphne Major. The Grants spent six months of the year each year since 1973 capturing, tagging, taking blood samples, and releasing finches from the islands. Peter Grant also helped to discover that natural selection by itself is not evolution but a mechanism within the complex process.

They were the subject of the book The Beak of the Finch: A Story of Evolution in Our Time by Jonathan Weiner (Alfred A. Knopf, 1994), ISBN 0-679-40003-6, which won the Pulitzer Prize for General Non-Fiction in 1995.

They won the 2005 Balzan Prize for Population Biology. The Balzan Prize citation states:
 * "Peter and Rosemary Grant are distinguished for their remarkable long-term studies demonstrating evolution in action in Galápagos finches. They have demonstrated how very rapid changes in body and beak size in response to changes in the food supply are driven by natural selection. They have also elucidated the mechanisms by which new species arise and how genetic diversity is maintained in natural populations. The work of the Grants has had a seminal influence in the fields of population biology, evolution and ecology."

Rosemary Grant was made a Fellow of the Royal Society in 2007.