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.
Don't post to me anymore.
You are an obnoxious, lying, jerk.
No, because you have been nothing but insulting, baiting, contradictory, and abusive in this thread.
YOU want everyone else to 'mind their own business' because YOUR posts weren't to them, but you don't want to show teh same courtesy.
You then go on to 'warn' others not to post to you because you have your contradictions posted back to you like this:
"Mind your own business."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=273#273
"This is an open forum and people are allowed to post about whatever is posted."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=285#285
"Mind your own business."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=298#298
You then tell people they're gay:
"Are you coming out?:)"
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=306#306
You call people cowards:
"You're the one defending a coward who makes statements she refuses to back up."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=312#312
"Keep standing up for your coward friends."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=327#327
you've done nothing but badger, bait, insult, and atatck since yesterday, and then you have the gall to say this:
"you should refrain from making an ass of yourself."
http://www.freerepublic.com/focus/f-chat/1525629/posts?page=329#329
"3rd warning; next has consequences. DON'T POST TO ME."
No dice pal.
You were asked to leave nics alone more than once.
ASKED.
And you did not listen.
AM, I will ask that you please take into consideration that CG was asked to stop his attacks and he did not, yet he wants to make threats about "Not posting to him" having consequences.
He does not want to leave nicmarlo alone, after repeatedly being asked ot do so.
I have asked 3 time for this poster to not post to me. I would love nothing more than to be done with this thread.
*checking watch*
"Awaiting your "proof" and "defense" of the comments made about me in post #346.
*checking watch*"
I already provided evidence for post # 346. You posted half of the statement I made and made it seem like it was the whole statement. I never said, "I have no patience." I said, "I have no patience though for those who make statements and are too timid to back them up." Did you not think I could just look up what you said?
Prove I am a creationist. When have I ever said that?
Does lying make you think your God will love you any more? Do you consider OK if you are Lying For The Lord? Is this the best you can do?
I lied because I quoted and made fun of you? Prove I lied. Prove I believe in God while you're at it.
btw...That last statement I quoted has to be the strangest, most compelling argument that you are not just slightly unhinged and incapable of rational debate. I'll be waiting.
*Still checking watch*
Anyone reading that original post would read it as a play on your own words to use them as a parody.
Proof of a "lie"? Laughable.
Only proves what I said earlier, that you can dish out ridiculous insults, but can't take them back. You are possibly the most thin skinned human I've encountered.
*Yawning indifferently*
I invited my friends to this fly thread some of them seem to feel they have cross the species barrier....
as you must have noticed they feel they have things in commons also you must have noticed there are snakes, sharks, turnips communicating with each other here.
Tread nicely!:)
I haven't seen you do anything but give out insults to this point. You claim you are debating facts, you've not debated one fact for the better part of a day now from what I can see; but with each post you only prove yourself to be an obnoxious poster boy of ignorance beyond even the most unhinged Democrat.
I. Am. Outta. Here. For. Tonight.
Looking forward to your unhinged reply.
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