Nails – we clean them, trim them, paint them, and sometimes even wear fake ones! But why do we have them in the first place? We talked to paleontologist Alexander Claxton about the evolutionary reasons behind having nails.

Got a question that you just can’t nail down? Send it to us at BrainsOn.org/contact, and we’ll help point afinger at the answer.

See omnystudio.com/listener for privacy information.