Common ancestor Question?

Question

just so i dont confuse you ill just read the whole question. .
Biologists discovered two squirrel species living on opposite sides of the Grand Canyon. They hypothesize that the species evolved from a cmmon ancestor. What observations or experiemnts could provide evidence for this hypothesis?
thanks a lot

Answer 1

A species is defined as a group of animals that don't interbreed with another group, even if they are actually capable of doing so and the offspring are both viable and fertile. So it may well be that these two species are identical except that they are separated by the Grand Canyon, which they are unable to cross.

Comparison of their DNA would provide the strongest evidence of how closely related they are.

They may also have similar behavioural characteristics which are common to both species but which other squirrel species do not have.

You could try keeping a male of one species with the female of the other and see if they interbreed. This usually indicates that the two species are closely related, especially if the offspring are themselves fertile.

Of course, if you trace their lineage back far enough, any two animals share a common ancestor...

Answer 2

One can look at the period the Grand Canyon was not there, and do a survey of existing squirrel species at that time.
Comparisons can be made to link the current groups back to the group before the Grand Canyon.
You can also look at similar morphological characteristics that they currently share. They may be able to still interbreed if brought together in a lab (under the biological species definition - even if they interbreed in a lab, they are different species because they cannot interbreed in nature "separated by the Grand Canyon".
A comparison of DNA can be made, and mtDNA is often used to determine relatedness due to the fact that the mtDNA only comes from the mother and not the father.

Answer 3

One could look for skeletal fossil remains of the ancestral squirrels on both sides of the canyon. IF the hypothesis is correct, the ancestral squirrels should be identical on both sides of the grand canyon.

DNA sequencing would be expected to show that these squirrels are more closely related to each other than they are to other species of squirrels in other locations.