Return to MCAT® Blog Homepage

MCAT Biology Question — Finches

On a particular chain of islands, 14 species of finches arose from a common ancestor. This is an example of:


a) evolutionary bottleneck

b) genetic drift

c) commensalism

d) adaptive radiation




Separate species arising from a single ancestor refers to adaptive radiation.

a) evolutionary bottleneck, incorrect, An evolutionary bottleneck refers to a severe population crisis that causes a shift in allelic frequencies in survivors.

b) genetic drift, incorrect, Genetic drift refers to loss of an allele in small populations due to all members with the allele dying.

c) commensalism, incorrect, Commensalism refers to a relationship between species in which only one species benefits from the relationship while the other is unaffected.

d) adaptive radiation, correct.

Want more MCAT practice?

We’ve got options for every schedule and learning style!

From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!

Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT expert using the form below. No obligation, just expert advice.

Create your Free Account to access our MCAT Flashcards SIGN UP NOW
MCAT is a registered trademark of the Association of American Medical Colleges (AAMC), which is not affiliated with Blueprint.