Dna or protein can be used as a molecule clock that tells how long it has been since two species have diverged from a common ancestor

DNA or protein can be used as a ''molecular clock'' that tells how long it has been since two species have diverged from a common ancestor. The fossil record is usually derived from sedimentary rocks laid down millions of years ago.

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse