SSS 2009-07-24(在线收听) |
This is Scientific Ameican's 60-Second Science. I'm Karen Hopkin. This will just take a minute? Forget the meek. If the Earth keeps getting warmer, a recent study shows that it’s the small that are gonna come out on top—at least in the world’s oceans. With global temperatures on the rise, scientists are trying to figure out what a warmer earth will mean for worldwide ecosystems. In aquatic environments it seems two responses have already come into play. First, species are seeking higher altitudes and latitudes so they can stay in their comfort zones. Second, organisms are shifting key events in their life cycles, like when algae bloom or fish spawn. Now researchers writing in the Proceedings of the National Academy of Sciences have discovered a third rule, if you will, that governs how fish and other ocean-dwelling critters are working to beat the heat: they’re shrinking. Makes sense because a smaller body means a bigger surface area to body volume and more efficient heat dumping. The researchers reviewed long-term surveys and other published results and found that the number of smaller-sized species is on the rise. And that within each species, fishes of every age are just a little bit littler than they used to be. Holy miniature mackerel. |
原文地址:http://www.tingroom.com/lesson/sasss/2009/7/99110.html |