#18- Zoologist: Every domesticated large mammal species now

[Administrator]

Complete Question Explanation

Assumption. The correct answer choice is (B)

Your task in this Assumption question is to select the answer choice containing information required
for the zoologist’s argument to be valid.

Premise: every domesticated large mammal species now in existence was domesticated
thousands of years ago

Premise: since that time, people undoubtedly tried innumerable times to domesticate
each of the wild large mammal species that seemed worth domesticating

Conclusion: thus, most wild large mammal species in existence today either would be
difficult to domesticate or would not be worth domesticating

Because there is no “rogue” information in the conclusion, this is a Defender type assumption
question, meaning the correct answer will raise a possible objection to the conclusion in order to
dismiss it, thereby defending the conclusion. When an Assumption stimulus contains a time shift, in
this case from thousands of years ago to today, a typical weakness in the argument is that the author
has assumed the conditions in existence in the past remained the same. So, your prephrase is that the
correct answer will raise the possibility that something about domesticating wild animals changed
over the past thousands of years, but will then dismiss the possibility.

The incorrect answers will not contain information required for the conclusion to be valid. Instead,
they will support the conclusion, have no effect on the conclusion, or weaken it.

Answer choice (A): It is not necessary for the conclusion to be valid that people have in fact tried
to domesticate each large mammal species. The conclusion was not absolute in nature, but rather
referred to “most” species, and was limited to whether it would be difficult to domesticate, or
whether the animals would be worth domesticating.

Answer choice (B): This is the correct answer choice. The information in this choice is required
for the conclusion to be valid. If it were much easier to domestic wild large mammal species now
than in the past, that information would undermine the zoologist’s conclusion.

Answer choice (C): Those lose large mammal species that were domesticated in the past but then
became extinct are not relevant to the conclusion, and so this information is not required for the
conclusion to be valid.

Answer choice (D): This choice has no effect on the conclusion, because the argument did not
attempt to reach this level of specificity regarding what makes a species “worth” domesticating.

Answer choice (E): The identity of the first species to be domesticated is irrelevant to the conclusion,
and so this information is not required for the conclusion to be valid.

[jiyounglee]

Premise: Every domesticated large mammal species now in existence was domesticated thousands of years ago.

domesticated large mammal species now in existence domesticated thousands of years ago

Premise: Since those days, people undoubtedly tried innumerable times to domesticate each of the wild large mammal species that seemed worth domesticating.

wild large mammal species that seemed worth domesticating people undoubtedly tried to domesticate

Conclusion: most wild large mammal species in existence today either would be difficult to domesticate or would not be worth domesticating.

wild large mammal species in existence today difficult to domesticate or not worth domesticating

I have a trouble in connecting the dots between large mammal species and wild large mammal species. Are they referring to the same mammal species?

Can you elaborate in breaking down and understanding the stimulus?

[Nikki Siclunov]

Hi jiyounglee,

Premise: Every domesticated large mammal species now in existence was domesticated thousands of years ago.

domesticated large mammal species now in existence domesticated thousands of years ago

Premise: Since those days, people undoubtedly tried innumerable times to domesticate each of the wild large mammal species that seemed worth domesticating.

wild large mammal species that seemed worth domesticating people undoubtedly tried to domesticate

Conclusion: most wild large mammal species in existence today either would be difficult to domesticate or would not be worth domesticating.

wild large mammal species in existence today difficult to domesticate or not worth domesticating

I have a trouble in connecting the dots between large mammal species and wild large mammal species. Are they referring to the same mammal species?

Can you elaborate in breaking down and understanding the stimulus?

Thanks for your question! This is a prime example of why you shouldn't be too focused on the conditional structure of the argument: although your breakdown is technically correct, it's actually prevented you from seeing the forest from the trees (so to speak). Check out this blog post I wrote awhile back on this very issue:

Conditional Reasoning: Do You See It Everywhere?

To answer your specific question, here's how I'd break down the stimulus:

The author observes that all large domesticated animals alive today were domesticated thousands of years ago. Since then, people have tried to domesticate other large mammals, but have obviously failed, since no other large animals have since been domesticated. The author interprets this failure as proof that most wild large mammals alive today either would be difficult to domesticate (which is why we failed to domesticate them), or they aren't worth domesticating (so we haven't even tried).

This makes sense, up to a point. However, there is clearly an unwarranted assumption somewhere in there, so let's take a closer look at the conclusion: First, just because we tried (and failed) to domesticate certain wild large mammals in the past - say, elephants - that does not mean that it's still just as difficult to domesticate them. Perhaps advances in animal research would enable us to domesticate elephants today even if we failed to do so in the past. Similarly, just because we haven't bothered to domesticate certain wild large mammals in the past doesn't mean that they wouldn't be worth domesticating today. People's needs change: we didn't need domesticated whales 1,000 years ago. Today, they could be the star attraction at your local Disneyland, as disturbing as this may be

Essentially, the author commits a Time Shift error, assuming that a certain outcome in the past is necessarily predictive of the same outcome in the future. Answer choice (B) defends the argument against this error by stating that it is NOT much easier today to domesticate wild large mammal species than it was in the past. If you negate answer choice (B), the conclusion is immediately weakened: if it's easier to do domesticate these unruly animals today than it was in the past, perhaps there are some wild large mammal species that would not be difficult to domesticate! Since the logical opposite of answer choice (B) weakens the argument, it is the assumption upon which the argument depends.

Hope this clears it up! Once again - resist the urge to diagram every conditional reasoning stimulus. Only do so when it will help - not hinder - your understanding of the argument.

Thanks,

[15veries]

Is A wrong because it only says "each" but in the stimulus it says "each of the wild large mammal species that worth domesticating" AND "most wild large mammal species...either...or"?

[Claire Horan]

(A) is wrong because it says "each wild large mammal species," but the stimulus argument is limited to "each of the wild large mammal species that seemed worth domesticating." The argument does not require an assumption that it doesn't even make.

[15veries]

Hi thanks for reply.

I'm wondering about B this time.
If we negate B, it will be " It is much easier to domesticate large mammal species than it was in the past."
But I think the conclusion still holds one is because it only says "most" so there are some number of animals that were not domesticated.
Another is the conclusion only says "or" so even the negation destroyes A's possibility, there's still B...A or B after all and it could be most of them are just due to B (ppl were not interested)
Why this thinking is not allowed?

[Jonathan Evans]

15 Veries, in response to your question above:

If we negate answer choice B, as you put it: "It is much easier to domesticate large mammal species than it was in the past," then the conclusion does not follow. It is possible that perhaps no large wild animals today are worth domesticating, but if we invalidate half the conclusion, we have invalidated it all. It is definitively no longer the case that:

• Most wild large mammal species today would be difficult to domesticate or not worth domesticating

irrespective of whether they're worth domesticating.

Further, with respect to your question about "most," if we were to assume that for any large wild animal today, such an animal is much easier to domesticate, than for at least most wild animal species in existence today, such animals would be not difficult to domesticate.

15Veries also asks:

Oops..sorry this question is actually about Q18.
I'll repost there.
Basically I was wondering...
In the conclusion it says "either...difficult to domesticate(X) or...not worth domesticating(Y)"
and the correct answer says "not easier today to domesticate" but this only addresses X.
Can't it be true that most of those that are not domesticated are just not worth domesticating? (Y)
So the conclusion says X or Y is true. And necessary assumption connects the dot between X and premise. But if only Y is actually true then there is no need to assume answer choice B right?
Or is this mind set not appropriate to attack assumption question but weakening question?

You are correct, this approach of ruling out an answer because negated it invalidates what appears to be only part of the conclusion is fallacious. The conclusion is no longer valid. Perhaps a different conclusion might be possible, but not this one.

Good questions! I hope this helps.

[hassan66]

Hi,

I was debating between B and C and chose B. But I was still confused by C because I may have read it incorrectly. We don't care whether domesticated species are alive or extent. However, is another assumption the author makes that some of the wild large mammal species worth domesticating that people tried to domesticate 1000 years ago still extant?

Because if none of the large wild animals that they had tried domesticating a 1000 years ago were still present, then how would we know that it would be difficult to domesticate the species now?

[Robert Carroll]

hassan,

I don't see that assumption as strictly required. The attempts at domestication are ongoing, according to the author. The species extant today must have come from somewhere, but I don't need to make an assumption as strong as that they were around thousands of years ago. Regardless of when a species came into existence, the author claims that then-contemporary humans would have attempted domestication. A weaker assumption, like that at least some species alive today were alive long enough in the past for humans to have attempted to domesticate them, seems fine.

Robert Carroll

[ericau02]

can you please help me to try to understand how to connect the dots. For these forums it keeps saying match the pre phrase but I don't know or understand how to connect or match this pre phrase.