Logical Reasoning

PT116 · S3 · Q19 Today’s farmers plant only a

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Today’s farmers plant only a handful of different strains of a given crop.

Conclusion (Hence)

A disease that strikes only a few strains of crops, which would have had only minor impact in the past, would devastate the food supply nowadays.

Evidence

Today's farmers only plant a handful of different strains of a given crop, whereas in the past they had more diversity.

Evaluate

Given that ... today's crops lack the diversity that they had a few generations ago,

How could we argue that ... a disease that strikes only a few strains of crops would not devastate the food supply today?

Since this argument is basically a Comparison between the past and now, we would want to offset the bad thing about today's era (less crop diversity) with some other consideration that makes us sound less vulnerable to the threat of crop disease threatening our food supply.

Goal

Look for an answer that either makes us feel like less diversity is not really a bad thing that increases the threat of crop disease, or find an answer that makes it sound like something else nowadays is better than before, so that even though diversity would make us more vulnerable, this improved other thing could offset that and make us less vulnerable.

19.

Which one of the following, if true, would most weaken the argument?

In the past, crop diseases
No Impact
This conclusion is only about the sort of crop disease that would have had only minor impact on the food supply in the past. The author wasn't saying that in the past the food supply was never devastated. It's suggested that a disease that struck a large number of strains of crops could have done terrible damage. The author is focused only on how in the past a disease that only targeted a few strains wouldn't have been a systemic threat, and now that type of disease would be.
11% picked this
Correct
Affected crops can quickly be
Why this is right
This answer might not appeal to us much on a first pass, but it ends up being the best option we have for arguing that, "A crop disease that strikes a few strains of crops would not devastate the food supply today". If affected crops (i.e. ones that get the disease) can quickly be replaced from seed banks with other strains of those crops, then it doesn't sound like the food supply would be devastated. Temporarily strained, maybe. But if affected crops can be quickly replaced, it doesn't sound like much of an emergency. Let's say a corn farmer nowadays only plants strains L, M, N, O, and P, whereas back in the day a corn farmer would plant not only LMNOP but also strains X, Y, and Z. If a crop disease comes around and knocks out L, M, and N, this answer is saying that the corn farmer could quickly replace those affected crops, by using a seed bank that stores strains of X, Y, and Z. Historically, students have always hated the notion that, "if you're removing a diseased crop and then planting seeds of a new strain of that crop, don't you have to wait an entire growing season before that would do anything to solve your problem?" Maybe. It's possible that seed banks aren't just "seeds" but are more like germinated seeds in pots; in other words, a seed bank might be storing these strains at a point in the crop's life cycle that is closer to harvesting than if we were to just put a new seed in the ground. But if nothing else, we just have to accept that this answer, while a bit of a weak rebuttal, is still our strongest available rebuttal.
Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.
68% picked this
Some of the less popular
Strengthens, if anything
The contrast between Past and Present that this answer provides is that many of the popular strains being used today are less resistant to diseases, which just augments the author's claim that a crop disease could devastate our crops.
4% picked this
Humans today have more variety
Mixed Impact
The fact that humans have more variety in their diets initially sounds like something that might help us argue, "Sure, a crop disease could decimate the strains of crops affected, but it wouldn't devastate the food supply, since humans have a wide variety in their diet so they would just eat other stuff instead." But the second half of this answer says that humans still rely heavily on certain crops like rice and wheat, so that part strengthens the author's claim that our food supply could be vulnerable to a narrow crop disease (were it to attack rice or wheat crops).
1% picked this
Today’s crops are much less
Weak Impact
This is tempting because it tells us something about today's crops that makes them stronger than before, but it's not stronger in relation to crop disease. No matter how strong your corn crops are these days when it comes to pests and weeds, if the corn gets hit by a crop disease, it takes out that crop either way. And even if all your other crops are more plentiful then they were generations ago (because they are more resistant to pests and weeds), it doesn't change the fact that you no longer have any corn to harvest. Thus, there is now a shortage of corn in the food supply. In the correct answer, we're better able to argue that a corn farmer who loses her crop to disease would still be able to get corn into the food supply (reasonably soon).
16% picked this

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