Various forms of plant and animal life have longer life spans than <b>Homo Sapiens</b> (for example, Galapagos turtles and Sequoia trees). While scientists do not live long enough to study the complete life-cycle of these life forms, the development of a single organism can be inferred by observing many specimens at various stages. The same principle can be applied to astronomy or geology. Scientists can learn about the evolution of deserts and rock formations by observing various specimens.<br/><br/>Which of the following is an assumption underlying the passage?
Practise this LSAT question free, then download the PDF, watch the video walkthrough, or unlock timed mock exams for the full web bank.
AThere are many methods of approaching scientific material which lead to a wide variety of conclusions.
BRedwood trees and other endangered species need to be studied more before they become extinct.
CThere are many material features in our environment which are not observable or measurable by today’s methods.
DExamples of various stages of development of deserts and rock formations are available to scientists for observation and study.
EMethods of observation are the same for most subjects
✓ Correct answer: D. Examples of various stages of development of deserts and rock formations are available to scientists for observation and study.For the argument to be valid, scientists must have access to examples of various developmental stages of the species under study. For example, because the passage mentions astronomy, you could look at the life cycle of the planet Saturn. This planet has remained largely unchanged for hundreds of millions of years. Therefore, a scientist can’t study its development during a lifetime.
Keep practising. Use the free LSAT PDF, watch the YouTube walkthrough, or unlock all 10 web questions with timed mock exams.
Free practice here. Timed mocks when you are ready.
Study the LSAT Exam Prep 2026 Test free question explanations, download the PDF, then unlock timed mock exams on the web when you want exam-day practice.
Theory