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楼主，有一个JJ跟我做的PREP很像，但是不敢肯定，因为PREP讲的是蜥蜴，JJ提供者说得是，RHYONS， 好像名字恨不一样的说，不过结构内容看起来很类似，想想还是贴出来好了
版本一、傍水 710 Rhynos（单词貌似不对）在不同的岛却很多相似，有四种这个rhynos（好像是叫这个），体表特征各不相同，最后发现时基因有所决定，然后应该是暗示，几个岛之前是一体的，后来才分开，因为那四种在同一个岛上的并不是一个种类，反而是跟其他几个岛的对应种类有相似，而基因应该要考同一个栖息地决定的 下面是PREP上的原文 Anole lizard species that occur together
(sympatrically) on certain Caribbean islands occupy different habitats: some
live only in the grass, some only on tree trunks, and some only on twigs. These
species also differ morphologically: grass dwellers are slender with long
tails, tree dwellers are stocky with long legs, twig dwellers are slender but
stubby-legged. What is striking about these lizards is not that coexisting
species differ in morphology and habitat use (such difference are common among
closely related sympatric species), but that the same tree types of habitat
specialists occur on each of four islands: Puerto Rico, Cuba, Hispaniola, and
Jamaica. Moreover, the Puerto Rican twig species closely resembles the twig
species of Cuba, Hispaniola, and Jamaica in morphology, habitat use, and
behavior. Likewise, the specialists for other habitats are similar across the
islands. The presence of similar species on
different islands could be variously explained. An ancestral species might have
adapted to exploit a particular ecological niche on one island and then travel
over water to colonize other islands. Or this ancestral species might have
evolved at a time when the islands were connected, which some of these islands
my once have been. After the islands separated, the isolated lizard populations
would have become distinct species while also retaining their ancestors’ niche
adaptation. Both of these scenarios imply that specialization to each niche
occurred only once. Alternatively, each specialist could have arisen
independently on each of the islands. If each type of specialist evolved just
once, the similar specialists on different islands would be closely related.
Conversely, if the specialists evolved independently on each island, then a specialist
on one island would be more closely to other types of anoles on the same
island-regardless of their ecological niches-than it would be to a similar
specialist on a different island. Biologists can infer how species are
related evolutionarily by comparing DNA sequences for the same genes in
different species. Species with similar DNA sequences for these genes are
generally more closely related to each other than to species with less-similar
DNA sequences. DNA evidence concerning the anoles led to each other than to
species with less-similar DNA sequences. DNA evidence concerning the anoles led
researchers to conclude that habitat specialists on one island are not closely
related to the same habitat specialist elsewhere, indicating that specialists
evolved independently on each island. | 
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发表于 2009-9-1 05:35:00
祝楼主考试顺利!~ 