The world’s single most important marine calcifying organism, Emiliania huxleyi, may be able to evolve in response to ocean acidification conditions, reports a paper published online in Nature Geoscience this week.
The acidification of the world’s oceans, due to oceanic uptake of atmospheric carbon dioxide, could seriously impair marine calcifying organisms. Until now, studies looking at the effects of acidification on marine organisms have focused on physiological responses within the lifetime of individuals, and have largely ignored the potential for evolution. In a series of laboratory experiments, Thorsten Reusch and colleagues exposed populations of E. huxleyi to elevated concentrations of carbon dioxide, and around 500 asexual generations later they assessed their fitness under ocean acidification conditions. Although all populations fared worse when under ocean acidification conditions, they found that populations selected under elevated carbon dioxide conditions exhibited higher growth rates and a partial restoration of calcification, compared with populations kept under control conditions.
The researchers suggest that contemporary evolution could help to maintain marine microbial function in the face of global change.