Peter and Rosemary Grant

Peter and Rosemary Grant studying birds in 2007

Peter Raymond Grant FRS FRSC (born October 26, 1936) and Barbara Rosemary Grant FRS FRSC (born October 8, 1936) are a British married couple who are evolutionary biologists at Princeton University. Each currently holds the position of emeritus professor. They are known for their work with Darwin's finches on Daphne Major, one of the Galápagos Islands. Since 1973, the Grants have spent six months of every year capturing, tagging, and taking blood samples from finches on the island. They have worked to show that natural selection can be seen within a single lifetime, or even within a couple of years. Charles Darwin originally thought that natural selection was a long, drawn out process but the Grants have shown that these changes in populations can happen very quickly.

In 1994, they were awarded the Leidy Award from the Academy of Natural Sciences of Philadelphia.^[1] The Grants were the subject of the book The Beak of the Finch: A Story of Evolution in Our Time by Jonathan Weiner, which won the Pulitzer Prize for General Non-Fiction in 1995.

In 2003, the Grants were joint recipients of the Loye and Alden Miller Research Award. They won the 2005 Balzan Prize for Population Biology.^[2] 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.^[2]

The Grants are both Fellows of the Royal Society, Peter in 1987, and Rosemary in 2007. In 2008, the Grants were among the thirteen recipients of the Darwin-Wallace Medal, which is bestowed every fifty years by the Linnean Society of London. In 2009, they were recipients of the annual Kyoto Prize in basic sciences, an international award honouring significant contributions to the scientific, cultural and spiritual betterment of mankind.^[3] In 2017, they received the Royal Medal in Biology "for their research on the ecology and evolution of Darwin’s finches on the Galapagos, demonstrating that natural selection occurs frequently and that evolution is rapid as a result".^[4]