Darwin observed that tortoises of the nearby islands, although slightly different, belonged to the same species. How might he have known they were the same species?
A) He probably compared DNA sequence data from the different tortoises.
B) He probably compared the metabolism of the different tortoises and observed similar enzymes.
C) He may have heard that tortoises of different islands could mate with each other.
D) He may have moved one group of tortoises to a new island to observe accumulated changes.

Question

Quizplus · Accepted Answer

Darwin may have observed or heard about interbreeding between tortoises from different islands, which is a common characteristic of organisms of the same species. This suggests that despite their slight physical differences, they were still able to produce viable offspring. DNA sequence data (A) and enzyme metabolism (B) were not available to Darwin during his time, and D is not a likely scenario as it goes against ethical and ecological considerations of introducing non-native species to an environment.

Darwin Observed That Tortoises of the Nearby Islands, Although Slightly