PRIMITIVE pond-dwelling algae are helping to answer one of biology’s ultimate questions – why did sex evolve? It seems that combining genes with your pond-mates is all about repairing DNA when the going gets tough.
Sex is puzzling because many species, including some plants and reptiles, manage to reproduce perfectly well without it. Instead of combining their genes with another individual they simply churn out carbon copies of themselves.
Richard Michod and his colleagues from the University of Arizona in Tucson argue that sex started out as a way of repairing damage to DNA. A version of sex in bacteria backs…
