LSAT (Law School Admission Test)Reading ComprehensionEasy
Passage: "The 'Lamarckian inheritance' theory, proposed by Jean-Baptiste Lamarck, suggested that organisms could pass on traits acquired during their lifetime to their offspring. For example, Lamarck posited that giraffes developed long necks because generations of ancestors stretched their necks to reach high leaves, and this acquired trait was then inherited by their progeny. This idea contrasted sharply with Darwin's theory of natural selection, which proposed that advantageous traits arise through random variation and are selected for by environmental pressures, not acquired through individual effort. While Lamarck's specific mechanism of inheritance was largely disproven by modern genetics, his emphasis on the interaction between organisms and their environment, and the idea of gradual change over time, foreshadowed aspects of evolutionary thought that are still relevant today. Indeed, some epigenetic mechanisms, though not truly Lamarckian, demonstrate that environmental factors can influence gene expression across generations without altering the underlying DNA sequence." The author mentions the giraffe example primarily to:
- AIllustrate a key tenet of Lamarckian inheritance.
- BCompare Lamarckian inheritance with Darwinian natural selection.
- CSuggest that acquired traits can, in some cases, be inherited.
- DDemonstrate the scientific inaccuracy of Lamarck's theory.
Show answer & explanationAnswer & explanation
Correct answer: A. Illustrate a key tenet of Lamarckian inheritance.
The passage introduces the giraffe example immediately after defining Lamarckian inheritance ('For example, Lamarck posited...'). Its purpose is to provide a concrete illustration of how Lamarck believed acquired traits were passed down, which is a key tenet of his theory.
Why the other options are wrong
- B. The passage later contrasts Lamarck and Darwin, but the immediate purpose of the giraffe example is to explain Lamarck's idea itself.
- C. The passage mentions epigenetics as a *different* mechanism, not as an endorsement of Lamarck's specific acquired inheritance.
- D. While the theory was disproven, the author introduces the example to explain the theory, not primarily to demonstrate its inaccuracy at that point in the text.
Illustrative Function
The role of an example in a text to clarify, explain, or demonstrate a concept, theory, or general statement.
- Often introduced by phrases like 'for example,' 'for instance,' 'such as,' or 'to illustrate.'
- Helps make abstract ideas more concrete and accessible.
- Serves to reinforce understanding of the preceding general statement.
Memory trick: Examples Explain, Elucidate, and Emphasize.