Posted on 11/20/2005 9:27:40 AM PST 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.
You think that was a flying shark? I think he looks more like a leaping shark. : )
First of all, I didn't post to you, I posted to my friends, one in particular who wanted my opinion.
Secondly, what I posted was: I HAVE MY OPINIONS BUT WON'T POST THEM and gave the reason why.
Thirdly, the reason I refuse to state my opinions are because of people like YOU, which you continue to prove now, ad nauseum: YOU ALL ARE EVEN OBNOXIOUS TO PEOPLE WHO DON'T WANT TO STATE THEIR OPINIONS.
Now, knock it off.
No comment.
You should tell him you're really a turnip though......
Creationist COWARD Placemarker.
I'll be gone most of next week and might have to give up FR, mostly. Something for some to be thankful for.
We'll be here when you return.
If the anti-Evos will ever submit papers that can be tested and pass those tests then they will have a dog in this hunt. Until then ... well ...
But, if it makes you feel better to feel victimized by some mysterious Grand Conspiracy, then whatever floats your boat.
..not life. can't reproduce... uses someone's else's ribosomes.
I bet. But did you see the zot yesterday when a returning banee posted a prefectly ordinary news story about the Catholic church supporting evolution? It was old news and had been the subject of several threads, but it was a news story.
I haven't stated what my ideas are regarding evolution. Nor have I claimed victimhood. You put that label on me, and the other pro-evolution "person" insinuated I'm a (a) creationist and a (b) coward.
So far, to prove my point, now two of you have been demeaning toward me....and that's JUST for stating I won't discuss my ideas/opinions onthese threads.
It's much worse when someone disagrees with you all, and one doesn't need to read very many evolution threads to know what I'm saying is a fact.
I've read many evolution threads/opinions, but don't post. What you discount as trash scientists/works, I don't, nor does everyone who disagrees with your opinions of their works.
The possibility is very real. The probablitity is another question and I don't think anyone can give an answer that you can take to the bank.
I missed it.
I'm going to move into your stall at Darwin Central. Squatter's Rights.
You're such a man. /sarc
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