A group of anthropologists has argued that Europeans may not have been

Explanation

A group of anthropologists has argued that Europeans may not have been, as generally believed, the first to bring chickens to South America. The group cites European accounts dating from the arrival of Europeans in South America around five hundred years ago that suggest that the Inca had already incorporated chickens into religious ceremonies. Further, a DNA comparison suggests a Polynesian origin for a chicken bone unearthed at Chile's El Arenal site, where other artifacts have been dated to over six hundred years ago.

We see that the anthropologists have argued, in other words, that their conclusion is, the following:

Europeans may not have been, as generally believed, the first to bring chickens to South America

The anthropologists provide two pieces of evidence to support their conclusion:

European accounts dating from the arrival of Europeans in South America around five hundred years ago that suggest that the Inca had already incorporated chickens into religious ceremonies

a DNA comparison suggests a Polynesian origin for a chicken bone unearthed at Chile's El Arenal site, where other artifacts have been dated to over six hundred years ago

The question asks the following:

Which of the following would, if true, most seriously weaken the anthropologists' argument as reported above?

This question is different from many other GMAT Weaken questions, whose arguments support their conclusions in one main way rather that with two different types of evidence. All the same, having seen how the conclusion is supported, we can look for a choice that somehow weakens the support provided by one or both pieces of evidence.

A) Preserved sweet potatoes up to one thousand years old from Polynesian archaeological sites most likely originated in South America.

If anything, this choice strengthens, rather than weakens, the argument.

After all, the fact that sweet potatoes up to one thousand years old from Polynesian archaeological sites most likely originated in South America indicates that, as long ago as a thousand years, people traveled between South America and Polynesia, which provides further reason to believe that the chicken bone found at Chile's El Arenal site is of Polynesian origin and predates the arrival of Europeans around five hundred years ago.

Eliminate.

B) The ages of other chicken bones found in the vicinity of the El Arenal site have been established by an absolutely irrefutable method.

This choice has a vibe of weakening the argument. By saying that the ages of other chicken bones have been established, it attempts to give us the impression that the piece of evidence we have that involves a chicken bone somehow does not support the anthropologist's conclusion.

However, the truth is that this choice has no effect on the argument. After all, it doesn't say how old the other chicken bones are. So, we don't know whether their ages indicate that they are from before or after Europeans brought chickens to South America. In other words, the fact that the ages of the other bones have been established is irrelevant without information on what those ages are.

Eliminate.

C) Analyses of ancient Polynesian canoes suggest that they could have been used for voyages to places as far away from Polynesia as South America.

As is the case with choice (A), if anything, this choice strengthens, rather than weakens, the argument.

After all, the fact that ancient Polynesian canoes may have been used for voyages to places as far away from Polynesia as South America is further reason to believe that the chicken bone found at Chile's El Arenal site is of Polynesian origin. After all, if the canoes could have been used for such voyages, then we have some confirmation that it's possible that the chicken bone found at the site is from Polynesia.

Eliminate.

D) The Europeans often mistook certain South American ducks for chickens.

This choice weakens the support provided by the first piece of evidence, "European accounts dating from the arrival of Europeans in South America around five hundred years ago that suggest that the Inca had already incorporated chickens into religious ceremonies."

This choice indicates that, while it's true that there are European accounts dating from the arrival of Europeans in South America that suggest that the Inca had already incorporated chickens into religious ceremonies, that fact may not indicate that there were chickens in South America before the Europeans arrived because the Europeans who provided those accounts may have mistaken ducks for chickens.

Notice that this choice doesn't conflict with the facts of the argument. It doesn't say that there are not any European accounts that suggest that the Inca had already incorporated chickens into religious ceremonies when the Europeans arrived. Rather, it weakens the connection between the fact that those accounts exist and the conclusion by indicating that the accounts may not be accurate.

Keep.

E) Given ocean currents, it is just as likely that South Americans traveled to Polynesia centuries ago as it is that Polynesians traveled to South America.

This choice has absolutely no effect on the argument. All it says is basically that travel in one direction is just as likely to have occurred as travel in the other. It doesn't tell us how likely travel in either direction is to have occurred. So, it doesn't meaningfully affect what we know about the situation since it does not help to confirm whether travel between Polynesia and South America occurred.

Eliminate.

Correct Answer