Two populations of birds are found living on a remote island. Which of the following information is the most important in deciding if the birds belong to a single species, or to two separate species?

Question

Group of answer choices

They look similar, and share many physical characteristics.

They are all specialists and prefer similar habitats.

The males all sing very similar songs.

When individuals from different groups mate, the offspring are sterile.

All the birds appear to eat the same types and variety of food.

Answer 1

The most important information in deciding if the birds belong to a single species or to two separate species is:

When individuals from different groups mate, the offspring are sterile.

This information is crucial because it indicates that the two groups are reproductively isolated from each other, which is a key criterion used to define separate species according to the biological species concept. If two groups can mate but produce sterile offspring, it suggests they are distinct species, as they cannot successfully reproduce and produce viable, fertile offspring.