Posted on 11/20/2005, 5:27:40 PM by restornu
Scientists at the University of Arizona may have witnessed the birth of a new species. Biologists Laura Reed and Prof Therese Markow made the discovery by observing breeding patterns of fruit flies that live on rotting cacti in deserts.
The work could help scientists identify the genetic changes that lead one species to evolve into two species.
The research is published in the Proceedings of the National Academy of Sciences.
One becomes two
Whether the two closely related fruit fly populations the scientists studied - Drosophila mojavensis and Drosophila arizonae - represent one species or two is still debated by biologists.
However, the University of Arizona researchers believe the insects are in the early stages of diverging into separate species.
The emergence of a new species - speciation - occurs when distinct populations of a species stop reproducing with one another.
When the two groups can no longer interbreed, they cease exchanging genes and eventually go their own evolutionary ways becoming separate species. Though speciation is a crucial element of understanding how evolution works, biologists have not been able to discover the factors that initiate the process.
In fruit flies there are several examples of mutant genes that prevent different species from breeding but scientists do not know if they are the cause or just a consequence of speciation.
Sterile males
In the wild, Drosophila mojavensis and Drosophila arizonae rarely, if ever, interbreed - even though their geographical ranges overlap.
In the lab, researchers can coax successful breeding but there are complications.
Drosophila mojavensi s mothers typically produce healthy offspring after mating with Drosophila arizonae males, but when Drosophila arizonae females mate with Drosphila mojavensis males, the resulting males are sterile.
Laura Reed maintains that such limited capacity for interbreeding indicates that the two groups are on the verge of becoming completely separate species.
Another finding that adds support to that idea is that in a strain of Drosophila mojavensis from southern California's Catalina Island, mothers always produce sterile males when mated with Drosophila arizonae males.
Because the hybrid male's sterility depends on the mother's genes, the researchers say the genetic change must be recent.
Reed has also discovered that only about half the females in the Catalina Island population had the gene (or genes) that confer sterility in the hybrid male offspring.
However, when she looked at the Drosophila mojavensi s females from other geographic regions, she found that a small fraction of those populations also exhibited the hybrid male sterility.
The newly begun Drosophila mojavensis genome sequencing project, which will provide a complete roadmap of every gene in the species, will help scientists pin down which genes are involved in speciation.
Mind your own business.
Thanks sharky.
Apparently, he feels the need to continue being.....obnoxious.
Judging from your behavior, I'm more man that you could ever be.
"Mind your own business."
No.
"This is an open forum and people are allowed to post about whatever is posted. "
Wow, a contradictpory statement!
You just told me to mind my own business!
Now we know not to take you seriously.
Yes.
You want ME to mind my own business.
You'd better mind yours then.
"Judging from your behavior, I'm more man that you could ever be."
Judging from your behavior, you are afraid to back up your statements.
Nic: Do you have any examples of papers that were refused publication?
We have a winnah.
"This is an open forum and people are allowed to post about whatever is posted."
This after saying "Mind your own business."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=273#273
Wonderful contradictions!
Isn't this just an extreme form of parasitism? .
Funny, all you've shown to anyone is insults, arrogance, and baiting.
I'm seriously doubting you have anything real to offer to a debate except insults arrogance and baiting.
How dare you contradict yourself.
You told me to mind my own business, and then you hided behind this being a public forum.
Now either you mind your own business, or this is an open public forum and I don't have to mind my own business.
YOU cannot have it both ways.
Stop digging.
You are really sounding foolish and like a truly nasty piece of work, far from the detached science expert you feign to be.
"Oh please, you're really embarrassing yourself."
I'm, embarrassing myself?
Who said to mind their own business?
HInt: That was you.
Who hid behind this being a public forum when it suits them?
Hint: That was you.
Suggestion: If you want to debate something, be honest about it, and non-insulting.
You're coming off like a halfcocked hothead who thinks nicety applies to everyone but them.
If you want me to butt out and mind my own business, you'll have to butt out and mind your own business as the post you started this over wasn't even to you.
"Than mind your own business "
Sorry, this is a public forum.
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=285#285
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