再次求解一道逻辑题

akatsuki09

GWD6-Q40:

It is theoretically possible that bacteria developed on Mars early in its history and that some were carried to Earth by a meteorite.  However, strains of bacteria from different planets would probably have substantial differences in protein structure that would persist over time, and no two bacterial strains on Earth are different enough to have arisen on different planets.  So, even if bacteria did arrive on Earth from Mars, they must have died out.

The argument is most vulnerable to which of the following criticisms?



A.    It fails to establish whether bacteria actually developed on Mars.

B.    It fails to establish how likely it is that Martian bacteria were transported to Earth.

C.    It fails to consider whether there were means other than meteorites by which Martian bacteria could have been carried to Earth.

D.    It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria.  

E.     It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.
本人现在是在A和D这两个选项之间卡住了，请问大伙能够提点一下么？

ARCHER420

选D。很明显。如果所有地球上现有的细菌都是从火星来的，就不用比较了。
A说没有证明细菌是否真正在火星上演化。力度没有D好。

akatsuki09

二楼的，你的图标也太性感了吧

ARCHER420

二楼的，你的图标也太性感了吧

-- by 会员 akatsuki09 (2009/11/1 22:39:23)

谢谢

风林火山

其实我觉得A不是力度不好，而是A否定了一个原文认为可能的情况。属于讨论区域转移了，这里重点不是说细菌是否会在火星上发展，而是要攻击作者的推理——因为地球上的细菌蛋白结构无差异，所以来自火星的细菌都灭绝了。我觉得这是A不能选的原因。

sangchangtw

agree with四樓的~ 文中第1句就提到:
"It is theoretically possible that bacteria developed on Mars early inits history and that some were carried to Earth by a meteorite."
所以這已經是前提囉~