At the Ecological Society of America's annual meeting this week, the University of Chicago in Illinois' Tim Wootton and Cathy Pfister told attendees that they suspect that sheer numbers are more important than genetic diversity to species threatened with extinction, says Ed Yong at the Nature News blog. The husband-and-wife team's results come from a 12-year-long experiment conducted on extinction and conservation. "Understanding the relative importance of these two factors is key to designing effective conservation strategies," Yong says. "It may be common sense to focus on boosting numbers if demographics matter more, and to put together breeding programs that expand the remaining gene pool if genetics rule."
Wootton and Pfister studied the sea palm Postelsia, breeding several populations of the plant with varying degrees of genetic diversity, and then transplanting them onto patches of shoreline in groups of different sizes. "After 12 years, smaller populations were less likely to have survived than larger ones, and, among the populations that did disappear, smaller ones did so more quickly," Yong says. "Crucially, genetic diversity did not influence the odds of a population's survival." However, it's still unknown whether the results will apply to other species, particularly as the sea palm is a stationary plant, whereas other species like the cheetah are mobile, Yong adds.