According to a theory advanced by researcher Paul Martin, the wave of species extinctions that occurred Line in North America about 11,000 years ago, at the end of the Pleistocene era, can be directly attributed to the arrival of humans, i.e., the Paleoindians, who were ancestors of modern Native Americans. However, anthropologist Shepard Krech points out that large animal species vanished even in areas where there is no evidence to demon-strate that Paleoindians hunted them.Nor were extinctions confined to large animals: small animals, plants, and insects disappeared, presumably not all through human consumption. Krech also contradicts Martin’s exclusion of climatic change as an explanation by asserting that widespread climatic change did indeed occur at the end of the Pleistocene. Still, Krech attributes secondary if not primary responsibility for the extinctions to the Paleoindians, arguing that humans have produced local extinctions elsewhere.

Which of the following, if true, would most weaken Krech’s objections to Martin’s theory?

A. Further studies showing that the climatic change that occurred at the end of the Pleistocene era was even more severe and widespread than was previously believed
B. New discoveries indicating that Paleoindians made use of the small animals, plants, and insects that became extinct
C. Additional evidence indicating that widespread climatic change occurred not only at the end of the Pleistocene era but also in previous and subsequent eras
D. Researchers’ discoveries that many more species became extinct in North America at the end of the Pleistocene era than was previously believed
E. New discoveries establishing that both the arrival of humans in North America and the wave of Pleistocene extinctions took place much earlier than 11,000 years ago

Please explain in a detailed way.Nice explanation will be appreciated with kudos ) . OA after explanations.
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Martin's theory : Extinction was due to arrival of human at the end of Pleistocene era.

Krech's theory : Large animals vanished elsewhere too.
And, not only large animals did extinct.
Climate change also occurred at the same time.
Human interface was secondary.

We have to weaken Krech's opposition to Martin's theory.

Krech contradicts Martin's theory by saying that climate change occurred at the end of Pleistocene era.

It is explicitly mentioned in the passage in line - 'Krech also contradicts Martin’s exclusion.....'.

Choice 'C' says climate changes have occurred even in previous and subsequent Pleistocene eras. So clearly, this is not the reason for extinction.

All of the , B, D & E support one way or the other to Krech's theory.

Am I correct ?
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B.

OA pls.

what's the source of this question?

IMO C.


B is in line with the argument of Krech.

Krech said climatic change is not included in the Martin's theory and it could be the reason for the extinction of the species.
C says that climatic changes happened before too but did not result in the extinction of the species.
* ===> Only issue here I see is that we need to make an assumption in C that similar wave of extinction did not happen in the previous and subsequent eras.*
still C is the best option here.
Opinions please!
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Consider kudos for the good post ...
My debrief : journey-670-to-720-q50-v36-long-85083.html

Situation:

Paul Martin believes that the arrival of humans i.e. the Paleoindians were the responsible factor for species extinction
Shepard Krech believes that the human is not the primary responsible factors for the species extinctions, climate is.

What will weaken Krech's objection/belief?

If the climate changes that is claimed to have cause extinction had been there before the humans arrived, and the species were still there when the humans arrived, the climate changes clearly did not cause the extinction. This finding therefore weaken Krech's belief that climate was the responsible factor.

A The severity of the climate changes were not linked to the extinction, this could strengthen Krech's belief
B The indication that Paleoindians made use of the small animals, plants, and insects does not indicate that human hunt (cause extinction) and made use of them.
C This clearly weaken Krech's belief by stating that the similar climate changes that took place before human arrivals did not cause the extinction
D The argument focus on the cause of the extinction, not on the number of extinct species
E The earlier indication of human arrival and Pleistocene extinctions further complicate the argument


IMO C

The OA is B, please see here :

http://www.beatthegmat.com/martin-s-theory-t50855.html
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took me almost 3:30 min to finalize B.
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