The formation of the canyon acted as a barrier that prevented any mating between the separated populations. This is an example of which stage of speciation?

Look at the picture below . what does this picture represent ?

Actual age your first developed of age well comparison age refers to absolute age true or false

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point