News FocusORIGINS

On the Origin of Sexual Reproduction

Science  05 Jun 2009:
Vol. 324, Issue 5932, pp. 1254-1256
DOI: 10.1126/science.324_1254

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Summary

Why sex? Why should so many species take such a labyrinthine path to reproduction, when straightforward routes are available? In the sixth essay in Science's series in honor of the Year of Darwin, Carl Zimmer describes new hints about how sex first emerged some 2 billion years ago and about the forces that have made it so widespread. The studies bolster a handful of hypotheses: Sex may speed up evolution, for example, or it may provide a better defense against parasites. In the past, scientists have focused on just one of these hypotheses at a time, but today many argue that several forces may be at work at once.