Reading ComprehensionDifficulty: Easy

PT150 S1 P4 Q22 Explanation

Evolutionary Implications of Cooking

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsLocal PurposeSociety

Keep going in LSAT Lab

  • Save & drill this skill — build targeted practice sets from questions like this one

  • Video walkthroughs — watch every question solved step by step

  • 81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

Free to start

Full official LSAT questions are available through LawHub. This page provides LSAT Lab's explanation, strategy, and review tools without republishing the full official question.

Passage

It might reasonably have been expected that the adoption of cooking by early humans would not have led to any changes in human digestive anatomy. After all, cooking makes food easier to eat, which means that no special adaptations are required to process cooked food. However, current evidence suggests that humans today such efficiency, we suggest, led to an inability to survive on raw-food diets in the wild.

Important questions therefore arise concerning what limits the ability of humans to utilize raw food. The principal effect of cooking considered to date has been a reduction in tooth and jaw size over evolutionary time. Human tooth and jaw size show signs of decreasing approximately 100,000 years ago; we suggest that this may prove to result from later modifications in cooking technique, such as the adoption of boiling.

The evolution of soft parts of the digestive system is harder to reconstruct because they leave no fossil record. Human digestive anatomy differs from that of the other great apes in ways that have traditionally been explained as adaptations to a high raw-meat diet. Differences include the smaller gut volume, longer small meat. Testing between the cooking and raw-meat models for understanding human digestive anatomy is therefore warranted.

What this question is testing

Local Purpose

Your task

Identify why the author included the referenced detail at that point in the passage — its function, not its content.

Common trap

Answers that merely repeat or summarize the topic of the detail instead of describing the role it plays.

Winning move

Ask what job the detail does for the paragraph, then for the passage's broader point.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
22.

The primary purpose of the parenthetical sentence near the end of the first

Answer choices

  1. Too Strong: required2% picked this

    identify the amount of time that is required for a behavior to have had an

    The author isn't defining "250,000 years" as the minimum required time for a behavior to have an impact on biological evolution. She's just suggesting that 250,000 years is "enough" time for it to have had an impact.

  2. Correct89% picked this

    provide support for the idea that cooking has been practiced for a

    Why this is right

    This answer isn't as good as a tweaked version of (A) would be, but it's not-wrong and it ends up being our best available answer. We were looking for something like "to suggest that cooking has been going on long enough to have impact on biological evolution". This answer doesn't talk about the biological evolution tie-in, but it does match up with "suggest that cooking has been going on long enough / it's not just a recent development".

    Skill tested: Local Purpose · how this choice captures the passage's function is the move to repeat next time.

  3. Too Strong: pinpoint / unable3% picked this

    pinpoint the time and place when humans became unable to survive

    The author isn't saying that 250,000 years ago, with the first use of fire and earth ovens, humans spontaneously and immediately became unable to survive on raw-food. Rather, the passage is saying that over our 200,000+ year history of cooking, we have anatomically changed (at the glacial pace of evolutionary change) into a modern day form where we can no longer survive on raw-food diets in the wild.

  4. Opposite4% picked this

    undercut the suggestion that the adoption of cooking affected the evolution of the

    The author isn't trying to "undercut" the idea that the adoption of cooking affected our anatomy. She's trying to build that case. She's supporting its plausibility by telling us that we've been cooking long enough (250k years) for us to have undergone anatomical change as a result.

  5. Wrong Purpose Detail-Sentence Bait2% picked this

    indicate the particular technology that early humans used to

    This answer is just taking an ingredient from the detail sentence ("earth ovens") and trying to invent a role for it. We know the purpose of talking about these earth ovens wasn't the specific cooking technology; it was how long ago they existed! The author was trying to establish that we've been cooking for long enough that there is time for it to have impacted our biological form via evolution.

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill
LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free