Can anyone some one me with these three questions

1) is the first one : the populations become adapted to different environments and eventually become so different that they cannot interbreed to produce fertile offspring

2) is the third one : they have identical physical characteristics

3) is the second one : the populations are isolated and thus do not interbreed .

hoped it helped !!!

Shania is trying to determine the oldest geologic unit on this map and the reason to why is she unable to do so is that  the units are all the same age.. when there is the same age, there will be no oldest geologic unit and that i cannot be credible.