Peter and Rosemary Grant bags Kyoto Prize for demonstrating rapid evolution in Darwin’s Finches
The script could not have got any better than this for the Grant’s who spent major part of their life studying Darwin finches evolutionary responses to environmental changes on islands of Galapagos. In this special year of evolution which celebrates 200th year of Darwin’s Birth and 150 years of publication of Darwin’s magnum opus “Origin of species”, Peter Raymond Grant and his wife Barbara Rosemary Grant won the prestigious Kyoto prize for their work “Demonstrating Rapid Evolution Caused by Natural Selection in Response to Environmental Changes”in basic sciences category. The Kyoto Prize is a Japanese award considered as equivalent to the Nobel Prize and the couple share $515,000 prize money.
Its indeed well deserved honor for two brilliant scientists , who have been traveling regularly since 1973 to the Galapagos to study their favorite finches.The Grants have spent six months of the year each year since 1973 capturing, tagging, taking blood samples, and releasing finches from the islands. Charles Darwin studied these birds for the first time during his famous Voyage of Beagle to the Galapagos Islands in 1835. Peter and Rosemary Grant provided some very valuable insights about origin and evolution of new species by studying Finches made famous by the great man – Charles Darwin.
The Grants spent nearly four decades studying Galapagos Finches and how fluctuations in environment changed the species within the population. The work by Grants is a perfect example to demonstrate natural selection in action. One of their most famous study is how the size and shape of finches changes depending upon the availability for food – seeds in this instance. Studying in a natural laboratory of some 100 acres island called Daphne Major , Grants observed something which could have made even Charles Darwin proud. They literally saw Darwin’s theory of evolution unfolding in front of their eyes. Darwin was of the opinion that natural selection operated over vast periods of time and couldn’t be observed.
When they began their research four decades ago, Grants wanted answers for some fundamental questions : Do members of different species compete with each other for food? If so, what might the evolutionary significance of that be? How are species formed, and why are some populations so much more variable than others? The Grants started studying Darwin finches for answers and main reason for the selecting this model is due to the fact that It’s a group of species that has evolved from a common ancestor in the Galapagos fairly recently and rapidly, making them well-suited to research.
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. The food source for the Finches (different kinds of seeds ) was the major cause for worry on Galapagos which largely depended on the changes in weather conditions. During their study they showed brilliantly how, in just a few generations, the beak size and shape of finches transformed as a result of the availability of different sized seeds, this again depended on the changes in weather conditions on the island. That particular study published in March 1996 issue of Ecology journal happen to be one of the highly cited work of Grant’s.
In the year 1977 there was a severe drought and vegetation was affected drastically leaving all kinds of seeds in scarcity. The small and soft seeds were quickly consumed leaving only large , hard seeds that the finches normally tend to ignore. In this harsh conditions birds with deep, strong beaks survived by gaining an advantage over smaller finches with less-powerful beaks. The Grants observed that smaller finches perished as they failed to come to terms of environment changes and finches with hard deep beaks won the battle of natural selection lived to reproduce. The offspring of the birds that survived the 1977 drought tended to be larger, with bigger beaks. So the adaptation to a changed environment has led to a larger-beaked finch population in the subsequent generation. However adaptation is not just one way traffic as it can go either direction also as observed in rainy weather in 1984-85. This resulted in more small, soft seeds on offer than fewer of the large, tough ones. Obviously the birds best adapted to eat those seeds because of their smaller beaks were the ones that survived and produced the most offspring.
The most exciting thing is that natural selection occurs strongly and repeatedly in environments like the Galapagos, where the climate fluctuates from very wet to very dry.
From these measurements they have told the story of how the process of evolution unfolds, publishing in the world’s leading scientific journals.
As the weather varied from year to year, causing sharp changes in the types of seeds and other food available, birds with different beak sizes were more or less able to eat the food at hand.
Those that could eat survived to reproduce – and over the centuries, the natural variations in beaks became some of the characteristics that distinguish one species from another. — Tom Avril
The couple authored a book ” How and Why Species Multiply: The Radiation of Darwin’s Finches” which narrates their experience with Finches at Galapagos islands.
Update : Read the related press release
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