Darwin Observed That Tortoises of the Nearby Islands, Although Slightly

Multiple Choice

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 saw they had similar enzymes.
C) He may have been told by local people that when tortoises of different islands were brought together, they could mate with each other.
D) He may have moved one group of tortoises to a new island and observed the accumulation of changes in the moved group.