Cornelia Dean makes note of a fact I had not thought much about. Conservation regulations that specify the minimum size of individuals that can be harvested, whether they be fish, bighorn sheep, or ginseng plants, increase the rate of evolution to favor smaller individuals that reproduce at an earlier age. This works against species health. Humans are harvesting mature adults, whereas natural predators would target smaller or weaker (old) individuals. Rates of evolutionary change are three times higher in species subject to “harvest selection” than in other species. Here is the abstract of Darimont et al.'s work.
Tuesday, January 20, 2009
Species conservation - how being helpful hurts
Cornelia Dean makes note of a fact I had not thought much about. Conservation regulations that specify the minimum size of individuals that can be harvested, whether they be fish, bighorn sheep, or ginseng plants, increase the rate of evolution to favor smaller individuals that reproduce at an earlier age. This works against species health. Humans are harvesting mature adults, whereas natural predators would target smaller or weaker (old) individuals. Rates of evolutionary change are three times higher in species subject to “harvest selection” than in other species. Here is the abstract of Darimont et al.'s work.
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There are many examples of perverse incentives resulting from government regulations to save species.
ReplyDeleteIn an attempt to save a rare species of bird in the North Carolina mountains, the government prevented the cutting down of trees within a 50 mile radius of where a bird was spotted. As a result, a small group of people with interest in the land hunted and killed the birds. Crazy, but true.