<Tr> <Th> Thesis </Th> <Td> (1985) </Td> </Tr> <Tr> <Th> Doctoral advisor </Th> <Td> Staffan Ulfstrand </Td> </Tr> <P> Peter Raymond Grant, FRS, FRSC, and Barbara Rosemary Grant, FRS, FRSC, are a British 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 . The Grants have shown that these changes in populations can happen very quickly . </P> <P> In 1994, they were awarded the Leidy Award from the Academy of Natural Sciences of Philadelphia . 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 . </P>

Who were the grants and what did they tell us about the galapagos
find me the text answering this question