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.
ewwwwwwwwwwwww...I was so waiting for that word coward again.
It makes my day when I get to see that from you. : )
Because it would probably be the 3001st out of 3001st post that you will say isn't credible.
And you're still a joke who thinks he can divine intent; did you help with hanging chads in Florida, too?
"And you're still a joke who thinks he can divine intent; did you help with hanging chads in Florida, too?"
And you're still a lying coward, whose intent doesn't need to be divined because you made specific statements you were afraid to defend. :)
For the third time, as posted back at #112:
I have my own ideas but, just like everyone else, since no one was around, it's all theories/speculation. Credible science includes the scientific method---the ability for anybody to reproduce the "test" and have the same effect. And that's not possible with much of these theories or speculations.That was in response to my friend's question, at post #105: "What do you think of this evolutionary stuff? Seriously."
For the past 100 posts, you still have not gotten me to answer my friend's question about what I think about evolution....and you've done nothing but harass and demean, divine my intent, call me a liar and other sundry names, simply because I initially made a three sentence statement to a friend. The reasons given why I refuse to state my beliefs/opinions/ideas with specificity have been proven beyond ridiculousness with you, and just with my refusal to post anything beyond my reasons for refusing. You're absurd.
Knock off the insults and the baiting.
A major reason for the difficulty in reconciling Intelligent Design theory with traditional science is that the logic of one flows in a direction opposite to that of the other.
Science describes the particular aspects of nature in order to discover more general aspects. Intelligent design would appear to offer a general quality of nature (indeed, the most general) as an explanation for the existence of all particulars. Thus it cannot be tested in the traditional manner.
But the full detail of the nature of man (I am as afflicted as anyone) as revealed in some of these posts shows no variance from that of Biblical teachings.
Another argument.....what and where have I said, specifically, anything about what I think of evolution?
"Knock off the insults and the baiting."
Mind your own business. He made statements he's afraid to defend.
"Mind your own business."
Funny, Nicmarlo's original post taht YOU responded to wasn't to YOU.
So.. Mind YOUR own business to begin with and people won't jump on you.
IF you want to play THAT game, then follow your own advice.
"He made statements he's afraid to defend."
No, she said she had an opinion, and didn't state it because of arrogant and abusive posters like you.
Nicmarlo is a SHE by teh by.
Again, if you want to say "mind your own business" then you shouldn't have posted to nicmarlo who hadn't addressed YOU.
Thanks darks. I tried explaining, several times now, that I initially posted an answer to a friend, not him, which he apparently believes I was lying about, as well.
For the record, genius boy, it's a she. And from what I can see, she's not only a far more decent person than you ever will be, she's smarter.
And you bring shame and sheer stupidity to this forum. Such a manly man......
I like his 'mind your own business' comment, when it is fact that your post that he initially responded to was to a friend and NOT him.
Perhaps he should.. mind his own business?
That would please me, immensely.
Yes, and it would be in keeping with his own 'advice' that I mind my own business.
Seriously, why should I mind 'my own business' when he couldn't be bothered to mind his own business?
If he can't take it, he shouldn't dish it out.
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