Sex-shift surprise

Estimates suggest that, although species become extinct naturally, the rate of human-induced loss is 100 to 1,000 times faster. Although the species identified in the study require immediate attention and may prove difficult to conserve, the authors believe their recovery is within reach. Indeed, several species that would have met all the researchers' criteria as endangered are now recovering as a result of successful conservation measures. These include the Seychelles warbler, the Seychelles magpie-robin and the Rodrigues Fody. " The 794 trigger species represent similar opportunities for conservation, " the researchers report. " Clearly, the primary response to avoid these impending extinctions will be to safeguard their sites through land purchase, conservation easements, community management, or protected area enforcement and to monitor their condition over time, " the researchers say. The researchers also point out that some species with wider geographical diversity, which were excluded from this study of locally distributed species, are also under serious threat and also in need of urgent conservation plans. The dramatic decline of the Asian Gyps vultures, is highlighted. " The sites we identify are a critical subset of global conservation priorities, complementing other efforts by focusing on relatively small scales and short time horizons: they are known places where extinctions are imminent unless immediate conservation action is taken, " the authors say. Mike Parr, secretary of the Alliance for Zero Extinction, the conservationist organisation that carried out the study, said: " At stake are the future genetic diversity of Earth's ecosystems and the global ecotourism economy worth billions of dollars per year. We have a moral obligation to act. " While most individuals in sexual species divide into either males or females, evolutionists face a challenge in explaining those species that do not conform to this type: hermaphrodites are the norm in some species and others show a more exotic mix of individuals with varying sexual identities. How these came about and what light they may throw on the evolution of separate sexes has been an intriguing question for both field and theoretical biologists. In a new study led by Stephen Weeks at the University of Akron, Ohio, reported in the Proceedings of the Royal Society (published online), researchers believe that one sexual system — males and hermaphrodites, that theoreticians believe to be evolutionary unstable — may actually be an ancient and enduring lifestyle in one group of freshwater shrimps. When evolution favours …