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.
Well, I am very late coming onto this thread, and when I do, I find a real fist fight going on...
Nicmarlo...I also question what you said in your post #128...you said, "No I doubt. I don't believe the crap I read in Science Journals, they won't print what scientists report who don't go along with their one way evolution ideas."...I know that there must be all sorts of reasons why a science Journal will turn down a particular article, but I am not sure that I would really believe that a science journal would turn down an article, simply because it ran counter to the theory of evolution, if the science behind the counter evolution theory was good...if the science or the techniques used were questionable then I can see the reason why a science journal might turn down such an article...
So, I would really like to see some facts of what sorts of articles were turned down, and for what reason...I am not looking to get into this ongoing argument, that seems to be going on, but I am looking for information...
Agreed, no debate required.
Where did I say that?
I have no patience
"You are beneath me."
This from a guy who can't make up his mind:
"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
"I handle them fine."
Funny, post 341 says otherwise.
Second warning: Don't post to me.
But just keep digging, pal.
Then leave nicmarlo alone.
See his post 350.
If he doesn't leave nics alone, it is no dice.
First of all, I don't participate in these threads, for the same reason I don't get on religion threads. As I've been repeatedly called a liar for other of my statements, my posting history will bear this out. Because I don't participate on these threads, I usually just lurk (hence, the reason why I won't particpate, as the obnoxiousness and rudeness is unbelievable...as you have witnessed thus far on this thread.) The point being, because I am not interacting, and just reading, I do not have at my recall, the numerous posts I've seen in the past regarding those specific articles/studies that would not be published in the Science Journal...nor do I have at my recall, the specific articles I've read on the web concerning works that other scientists considered as credible and reliable, but, nevertheless were refused publishing in journals. What I do recall reading was that refusal was due to the conclusions not fitting within the agenda of the editors/boards, not because of it being due to "junk" science.
IS NOT:
THAT: (My words): "No I doubt. I don't believe the crap I read in Science Journals, they won't print what scientists report who don't go along with their one way evolution ideas."(nicmarlo, post 128)
I'll be waiting, genius.
Interesting...well, I should be able to 'google' or 'askjeeves', and find some information on what you have said, and then need time to read any articles about this, and then make up my own mind...
thanks for the reply....
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