Evolutionary Biology

[Biologyyv]

I have an exam on Monday and need to find out a good answer to the following question, it is second year University level..

 

You have found a species of moluscs that vary morphologically within its' population and between its population. Nothing is known about the biochemistry or DNA variations. Design a set of experiments to determine the relative importance of natural selection and genetic drift in influencing variations.

 

Any help would be greatly appreciated! Thnks

[foodchain]

I have an exam on Monday and need to find out a good answer to the following question, it is second year University level..

 

You have found a species of moluscs that vary morphologically within its' population and between its population. Nothing is known about the biochemistry or DNA variations. Design a set of experiments to determine the relative importance of natural selection and genetic drift in influencing variations.

 

Any help would be greatly appreciated! Thnks

 

 

That sounds like a very broad question. It could be something of a cline with say some form of speciation occurring like one of the patrics or what not. It could be some new phenotype messing around with the chromatin or some other epigenetic factor. I guess for tests would be to see concentrations of the phenotype based on variables that may change in the population, such as what depth or temperature, or if it simply conveys some sort of benefit from predation or what not. If that all fails it might simply be just an aspect of drift that is existing currently on some neutral basis maybe?

 

I mean you have to have the variation and reproduction before you can have the selection, but a selection event or even a continuous landscape of such does not have to be all at once a strong selection. So my big guess is if you cant find any particular variable that could constitute any form of selection against or for the phenotype in question that its more or less a product of drift.

 

The only other option I could think of is maybe something pertaining to transposon behavior or some "mutagen" perhaps like pollution or a virus, or even HGT. I don’t know if by chance a single mutation can cause a cascade like effect of variation but I guess that would depend on where the mutation lands and again how well any mutants do.