How did the finch beak change during after the drought?Because the drought reduced the number of seeds and finches with bigger beaks were able to eat the larger and harder seeds so more of them survived.
How did the beak size of the ground finch change during the 1977 drought?In 1978 the Grants returned to Daphne Major to document the effect of the drought on the next generation of medium ground finches. They measured the offspring and compared their beak size to that of the previous (pre-drought) generations. They found the offsprings' beaks to be 3 to 4% larger than their grandparents'.
How did the finch beaks change between 1976 and 1978?1: Finches of Daphne Major: A drought on the Galápagos island of Daphne Major in 1977 reduced the number of small seeds available to finches, causing many of the small-beaked finches to die. This caused an increase in the finches' average beak size between 1976 and 1978.
What happened to many birds with small beaks during the 1977 drought?Now the next step: evolution. The Grants found that the offspring of the birds that survived the 1977 drought tended to be larger, with bigger beaks. So the adaptation to a changed environment led to a larger-beaked finch population in the following generation.
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What change occurred in the average beak size of the finch population after the drought of 1977?
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