Rosemary Grant is an evolutionary biologist who picked up where Darwin left off by watching natural selection in action amongst Darwin’s finches in the Galapagos archipelago. She has shown how the interactions of genetics, ecology and behaviour can rapidly modify the sizes of bodies and beaks, even giving rise to new species through hybridisation.
From 1973 onwards, Rosemary — with her husband Peter — collected data on the four species of finches on the island of Daphne Major. This preeminent field study encompasses body size, variation in songs, developmental genetics, DNA sequences, and causes and consequences of introgressive hybridisation. Rosemary demonstrated that a combination of morphology and learned song can act as a barrier to interbreeding.
The writer Jonathan Weiner made the Grants the subject of his book The Beak of the Finch: A Story of Evolution in Our Time, which won a Pulitzer Prize in 1995. In 2008, Rosemary was among the recipients of the Darwin–Wallace Medal, awarded every 50 years by the Linnean Society of London. She and her husband have written four books.