1. which of the following occurs prior to speciation?
a) organisms of different populations join together.
b) different species share the same space.
c) a population is divided.
d) a major change on earth takes place.

2. which of the following must be true of their individuals if two populations are no longer the same species?
a) they do not have any of the same genes.
b) they do not share any of the same space.
c) they do not resemble each other at all.
d) they cannot reproduce successfully with each other.

3. how does speciation start to take place on a genetic level between two isolated populations?
a) large numbers of mutations occur.
b) allele frequencies change in different ways.
c) new genes are added to one group.
d) recessive alleles become dominant.