Which of the following best sums up Ehrlich and Raven’s argument in their classic 1969 paper?
Explanation:
Option 1 is incorrect. Option 1 states that Ernst Mayr was wrong. This is a misrepresentation – physical separation does cause speciation but Ehrlich and Raven argued that it was not the only cause. Eliminate option 1. Option 2 is incorrect. Option 2 is factually correct. The three groups of butterflies was the direct observation of the study. However, it does not sum up the argument of Ehrlich and Raven. Eliminate option 2. Option 3 is correct. Option 3 summarizes the study – that while physical separation did cause speciation it was not as important as natural selection in causing speciation. Retain option 3. Option 4 is incorrect. Option 4 is vague. It does not specify the group of population in which gene flow is less common and more erratic. Eliminate option 4. Hence, the correct answer is option 3.
» Your doubt will be displayed only after approval.
Help us build a Free and Comprehensive Preparation portal for various competitive exams by providing us your valuable feedback about Apti4All and how it can be improved.