ANT 101 Lecture Notes - Lecture 7: Stabilizing Selection, Antimicrobial Resistance, Natural Selection
Document Summary
They captured every finch on the island and were able to tell the species names. They found that beak sizes was heritable. There was a severe drought in 1976, and a severe reduction of finches that had survived the drought. They had started with 1. 200 finches and by the end there were only 180 left in the course of 2 years. The seeds during this drought grew harder, stronger and larger than the seeds that were surviving previous to the drought and after that the seed size returned to normal. Larger beak sized birds were the ones that survived the drought better than the birds with smaller beaks. Previous to the drought- the majority of finches had smaller beaks but after the drought the average beak size remained larger. There was variation between the beak size but the average was larger beaks and after the drought the average break size increased and variation shrunk.
