#5 - Taste buds were the primary tool early humans used for

[pandapaws]

I get why E is correct but I don't completely understand why D is incorrect. I chose D because I initially thought the flaw in the argument was that the argument made a conclusion about the present based on evidence from the past, so D seemed attractive. I wanted to ask how this was wrong.

[Luke Haqq]

Hi pandapaws!

A stimulus isn't necessarily suspect just because it makes a conclusion about the present based on evidence from the past. To the contrary, the LSAT is replete with examples of conclusions about the present based on evidence from the past.

What should seem suspect here is that a new element appears in the conclusion. Namely, the conclusion is that the past evidence fully explains why present people can *distinguish* the mentioned four tastes. An issue becomes apparent to me in reading that--what's to say that people in the past also couldn't clearly distinguish these tastes? The first three sentences don't establish that they're the reason why people can distinguish sour, bitter, sweet, and salty.

Even if the people from the past under consideration ate a more limited range of food than people of the present, as (D) supposes, we're still left wondering if the use of taste to test for the healthfulness of foods is the causal reason why people can distinguish sour, bitter, sweet, and salty today.