Can sea urchins ­survive the ­greenhouse effect? Using genetic analy­sis to determine how marine organisms respond to warmer and more acidic oceans, Gretchen ­Hofmann, a University of California, Santa Barbara, marine biolo­gist, is finding troubling indications that the answer may be no.

After growing urchins (left) in conditions that mimic possible future climates, Hofmann's group studied select sequences of DNA to determine which of the urchins' genes had been activated in response to their environment. ­Hofmann focused on heat-shock proteins, which help stressed organisms repair other proteins. Early results show that the proteins work fine when urchins are confronted by warming water, but not when they also face the acidification caused by even modest increases in carbon dioxide--suggesting that urchins may have trouble adapting. Hofmann has built a DNA microarray specific to urchins in order to study genetic effects of climate change in greater detail.