He did it all for the finches (and their beaks).
Here's wishing everyone a Happy Darwin Day for 2015 (Darwin's 206th posthumous birthday)! Here is a short pictoral profile. And check out the hashtag #darwinday on Tumblr for more features and events. And, as a bonus, here is a new paper in Nature  that uses genome resequencing to better understand the adaptive variation in finch beaks.
Old Man Darwin
 Lamichhaney, S. Evolution of Darwin’s finches and their beaks revealed by genome sequencing. Nature, doi:10.1038/nature14181 (2015).