Help with Biology Question

[killian07]

What if you were assisting me and my colleagues with the research in Vancouver Lake, and you found
that the Lake has a large population of a particular copepod (a kind of zooplankton) that looks very
similar to, but not completely identical to, a copepod species commonly found in the Columbia River
near the Port of Vancouver. You hypothesize that the copepod population in Vancouver Lake originated
in the Columbia River, but was separated from the original stock when development along the river filled
in the natural connections to the Lake, and that the two populations are now two distinct species. You
decide to test this hypothesis experimentally.



Describe the approach you would use in this research project, with emphasis on the following questions:
What is a population and what is a biological species? How would natural selection help to explain the
differences between these two populations of copepods in the Lake and River? How would you test
whether the Lake copepods are a different species than the copepods found in the River? What results
would support your hypothesis that the copepod population in Vancouver Lake has diverged enough to
be considered a new species? If the Lake copepods are, indeed, a new species, which mechanism of
speciation most likely occurred: allopatric or sympatric speciation, and why?

[killian07]

Basically what I am thinking and what my research has concluded for me is that I should be asking myself whether or not the two possibly divereged species could produce viable fertile offspring if they were to interbreed. A population is a group individuals of the same species that live in the same area and interbreed, producing fertile offspring. Different populations may be isolated geographically from one another; thus exchanging genetic material only rarely. As far as testing the whether they are a different species....would I just talk about looking at their gene pools? And if they are different enough then that may be evidence of the two divereged?

[jonmoulton]

If you can breed the copepods in lab conditions, you could try crossing the two populations. It would be helpful if you had a method to determine whether you had made a successful cross. Can you think of a molecular biology method that you could use to prove a cross had occurred? Then if you can get viable offspring from crossing the F1s, you support the hypothesis that the two populations are the same species.