Reading Comprehension

[Reading Comprehension] 试题详情

The passage suggests that if a grass-dwelling anole lizard species evolved on one island and then traveled over water to colonize a second island, the grass-dwelling anoles on the two islands would eventually

Options:

develop very different DNA sequences
develop into different species that are more distantly related to each other than to tree- and twig-dwelling anoles on their own islands
come to differ significantly from one another in habitat use
develop into different, but closely related, species
evolve significant morphological differences

Correct:

D

Reading Comprehension

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[点此查看答疑][GWD]Reading Comprehension

老师好,做这题的时候定位好混乱,感觉整篇都是在讲同一物种在不同地方的进化,这题是考整体的题目吗? 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 differences are common among closely related sympatric species), but that the same three types of habitat specialists occur on each of four islands: Puerto Rico, Cuba, Hispaniola, and Jamaica.Moreover, the Puerto Ricantwig 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 traveled 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 may once have been. After the islands separated, the isolated lizard populations would have become distinct species while also retaining their ancestors' niche adaptations. Both of these scenarios imply that specialization to each niche occurred only once. Alternatively, each specialist could have arisen independently on each of the is lands. If each type of specialist evolved just once, then 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 related 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 researchers to conclude that habitat specialists on one island are not closely related to the same habitat specialists elsewhere, indicating that specialists evolved independently on each island. The passage suggests that if a grass-dwelling anole lizard species evolved on one island and then traveled over water to colonize a second island, the grass-dwelling anoles on the two islands would eventually A.develop very different DNA sequences B.develop into different species that are more distantly related to each other than to tree- and twig-dwelling anoles on their own islands C.come to differ significantly from one another in habitat use D.develop into different, but closely related, species E.evolve significant morphological differencs
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[点此查看答疑][GWD]Reading Comprehension

当初选对D,改错A是看了原文定位的问题,然后根据原文杀了D。L74-79文中说了,DNA相似的是,closely related的关系,DNA不同的,是不closely related。而根据L 80-结尾,不同的岛上分别进化,habitat specialists on one island are not closely related to the same habitat specialists (85) elsewhere 所以看到了分别独立进化且not closely related,就得出了错误答案A了
0评分
97浏览

[点此查看答疑][GWD]Reading Comprehension

老师好,做这题的时候定位好混乱,感觉整篇都是在讲同一物种在不同地方的进化,这题是考整体的题目吗? 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 differences are common among closely related sympatric species), but that the same three types of habitat specialists occur on each of four islands: Puerto Rico, Cuba, Hispaniola, and Jamaica.Moreover, the Puerto Ricantwig 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 traveled 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 may once have been. After the islands separated, the isolated lizard populations would have become distinct species while also retaining their ancestors' niche adaptations. Both of these scenarios imply that specialization to each niche occurred only once. Alternatively, each specialist could have arisen independently on each of the is lands. If each type of specialist evolved just once, then 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 related 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 researchers to conclude that habitat specialists on one island are not closely related to the same habitat specialists elsewhere, indicating that specialists evolved independently on each island. The passage suggests that if a grass-dwelling anole lizard species evolved on one island and then traveled over water to colonize a second island, the grass-dwelling anoles on the two islands would eventually A.develop very different DNA sequences B.develop into different species that are more distantly related to each other than to tree- and twig-dwelling anoles on their own islands C.come to differ significantly from one another in habitat use D.develop into different, but closely related, species E.evolve significant morphological differencs
0评分
65浏览

[点此查看答疑][GWD]Reading Comprehension

当初选对D,改错A是看了原文定位的问题,然后根据原文杀了D。L74-79文中说了,DNA相似的是,closely related的关系,DNA不同的,是不closely related。而根据L 80-结尾,不同的岛上分别进化,habitat specialists on one island are not closely related to the same habitat specialists (85) elsewhere 所以看到了分别独立进化且not closely related,就得出了错误答案A了

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