What is the Role of Gene Mutation in Speciation and Environmental Adaptation?

[iansmith]

Mutation in a single fly gene affects environmental adaptation, leading to reproductive isolation | By Cathy Holding



The path from single mutation to reproductive isolation in speciation may not be immediately obvious, but a technique reported by Anthony Greenberg and coworkers at the University of Chicago in the December 5 Science enables direct visualization of the effect of an alteration in a gene in an otherwise unaltered genetic background. It depends on precise integration of a specific gene into the correct genomic locus, and in this way, the role of a gene mutation in differential adaptation can be precisely observed (Science, 302:1754-1757, December 5, 2003).

Greenberg et al. examined the effect of an inactivating mutation in the Drosophila melanogaster gene desaturase 2, which has a role in pheromone production and hence mating in the fruit fly. In a genomic background of the inactive gene, ds2M, the authors introduced an active form of the gene ds2z precisely into the location of the endogenous gene, by recombination using FLP-FRT technology. They examined cuticular hydrocarbon profiles—the basis of pheromone chemistry—in the active and inactive lines and observed that the active profile was not recapitulated despite integration of active ds2, suggesting involvement of other, previously unrecognized gene systems. The authors also studied the role of the desaturase in cold tolerance and observed that active ds2 decreased cold tolerance and increased starvation tolerance when used to replace the inactive gene.

“Although the role of ds2 in premating isolation remains to be firmly established, we have identified a potential ecological basis for the maintenance of pheromone polymorphism as a result of strong geographical differentiation at the ds2 locus,” conclude the authors.

http://www.biomedcentral.com/news/20031205/03

 

[Monique]

How about the example of the black and white moths? I am not sure about the specifics of the story anymore, but the bottom line is the following:

all of a sudden the ratio of black to white moths started to shift and biologists has no clue what was going on, why this selection. Turned out that the tree that, say, the white moth was living in due to camouflation (sp?) was being logged down, which led them to be pray to birds who eat them. The black moths still had their tree and were surviving.

 

[agnostictheist]

I think that's a case of natural selection, not mutation... being a biochem i assume you know what mutation is and pobably much better than I (being a chemist by education)!

specation, is like a sepration of a species to the next this works and the most comman way, is via cladogeneis, basically the species, changes form one to the other, and there tends to be a anther group of species...that splits from them : i think its a result of geography. at last in part... or chance.

if there is no speartion (sepration) into to groups, and that one species simply changes into a new species then its called:

Anagenesis

 

[Phobos]

Originally posted by Monique
How about the example of the black and white moths? I am not sure about the specifics of the story anymore...

You mean this?
http://www.millerandlevine.com/km/evol/Moths/moths.html"

BTW, this link also serves as a response to anyone who says that study was bogus.

 

[nautica]

Originally posted by agnostictheist
I think that's a case of natural selection, not mutation... being a biochem i assume you know what mutation is and pobably much better than I (being a chemist by education)!

specation, is like a sepration of a species to the next this works and the most comman way, is via cladogeneis, basically the species, changes form one to the other, and there tends to be a anther group of species...that splits from them : i think its a result of geography. at last in part... or chance.

if there is no speartion (sepration) into to groups, and that one species simply changes into a new species then its called:

Anagenesis

Natural selection acts on mutations, either on present mutations or latent. Without mutations, natural selection would have nothing to select.

 

[agnostictheist]

Natural selection acts on mutations, either on present mutations or latent. Without mutations, natural selection would have nothing to select.

we are not nessecerly dealing only with Natural selection, while I mentioned it, my comment was centered around spectation.