690-730-790三战分手放方法放经验放感悟放建议

KhoiHoHOHo

今天要二刷了 求楼主分点人品和运气

阿尔的阳光

宋痂岛__ 发表于 2018-6-13 11:33
加你啦 看一下~

小岛我来烦你啦~~
这篇文章不知道你还有印象吗，有一道题目很迷想了很久。。。
你有空的时候再回我把。。估计看题要花一点时间。
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 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 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 islands.
    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 differences

我仔细比较过文中几个定位，前面是解释和假设，后面是推论和DNA验证。大意就是不同岛上的同一栖息地的specialists用DNA匹配之后发现确定演化成了不同物种，且假设中有这样一句话
“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.”
所以我选了B, 答案是D。。
求助你帮忙理理思路

宋痂岛__

阿尔的阳光 发表于 2018-6-15 11:13
小岛我来烦你啦~~
这篇文章不知道你还有印象吗，有一道题目很迷想了很久。。。
你有空的时候再回我把。。 ...

好我待会看一下

KayLin1704

谢谢楼主！！！

maggiezhang5

分析的太好了，谢谢小岛

猪小王

刚考完，V29，好像这个瓶颈怎么都突破不了。lz愿意在线辅导吗？

maggiezhang5

小岛你说的chase群号是多少呢？谢谢

nddddo

小岛，你发的SC 700-800 questions在哪里找的？我想去下载CR和RC的

谢谢~~

billyisfragile!

阿尔的阳光 发表于 2018-6-15 11:13
小岛我来烦你啦~~
这篇文章不知道你还有印象吗，有一道题目很迷想了很久。。。
你有空的时候再回我把。。 ...

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 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 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 islands.

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 differences

w76o09n21e48a

感谢分享！