In the early 1800s, darwin studied 13 kinds of finches. what did darwin hypothesize about these birds?

a. the different finches could breed and produce fertile offspring.

b. the finches were different species that shared a common ancestor.

c. their speciation took millions of years.

d. all 13 kinds of finches belonged to the same species.

Option B, The finches were different species that shared a common ancestor.

Explanation:

While conducting his study on the Galapagos Islands, Charles Darwin found that the different species of finches has some common ancestry link based on which he later proposed theory of natural selection

Darwin researched on finches as these are considered as fastest-evolving vertebrates and thus variation with the same species can also be noticed.

One such variation can be observed in the size and form of beak in finches that greatly differs from each other but the gene that is responsible for gene is coming from a common ancestor.

Hence, option B is correct.