Amixture with a constant composition

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction. this is an example of speciation.

One gene can influence trait(s). one trait can be determined by gene(s).