英語聽力文摘 大滅絕
Coextinction
絕種是指生物群體逐漸消失的過程。物種和較大族群常態(tài)性的滅絕，并由更進(jìn)步的形式所取代，這是進(jìn)化的正常過程。然而，從化石的記錄來看，有時會出現(xiàn)整個科目的動物和植物都突然消失的情形，這種現(xiàn)象稱之為大滅絕。
Y:Down,you konw how when we think about species going extinct, we think of them as functioning separately from other species.
D:Oh!So we think about saving the whales, but don’t really think about any other species with which endangered whales interact.
Y:Right.Well,A study published in Science suggests that extinction is actually a lot more complicated. The problem is that extinction of one species can cause the extinction of a bunch of others.
Scientists call this process coextinction. For example, take hummingbird flower mites. If hummingbirds went extinct, the mites would go extinct too because they would have no way of getting from flower to flower. The same goes if the flowers on which these mites depend for nectar and pollen go extinct.
In fact, according to this study, if you add up all the affiliate species that are expected to go extinct if the species on the endangered list goes extinct, you’re looking at an additional sixty- three-hundred endangered species.
And also important to know as we try to focus conservation efforts, especially since some species have more affiliate species thann others. The army ant(行軍蟻), for example, is host to over one hundred affiliate organisms, ranging from beetles and mites to ant birds. These kinds of species are keystone species in an evolutionary sense, and so are extremely important from a conservationstandpoint.
Even if coextinction isn’t the main reason for species extinction, it certainly is an insidious process that we can’t (1)afford to ignore.
Notes:
(1)afford to(有條件)做;能承擔(dān);買得起某物;支付的起
One can afford to lose anything, but dignity.
可以承受失去任何東西，但有尊嚴(yán)。
