More than 20 years of annual sampling of stickleback populations in the Alaska has enabled us to detect multiple, fascinating cases of contemporary evolution. Over a 10 yr period (five generations) we have documented evolutionary decline in egg size that was among the fastest cases of contemporary evolution ever recorded, and it was coincident with other life history changes predicted by theory. The change in egg size moved the population mean from one of the two largest in the region to the bottom percent. Other populations appear to exhibit cyclic changes in life history features, or to be responding to directional selection (primarily induced by increased productivity) with different changes in life history features (Baker). We have also observed rapid re-evolution of pelvic armoring in some, but not all populations historically devoid of piscine predators, to which predatory fish have been introduced (Kindinger). We are currently working to explain causes for the variation in patterns of contemporary evolution of life history and armor traits, and to determine whether anti-predator behavior has evolved in concert with armor (Wund, Golub).
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