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.
First of all, did you see post number 2, by the person who posted this thread? I was INVITED by ping to this thread by a friend of mine.
Secondly, did you bother to read the answer I already gave to another one of your mob friends?
So classless, clueless, and crude.
Nuff said.
Mind your own business.
;-)
Mind your own business.
TYhe post you jumped on, post 112, wasn't to you.
You were SO kind to offer up the following contradictions:
"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
Perhaps you should mind your own business?
Who's the coward?
You won't even retract your contradictions:
"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
"Perhaps you should mind your own business?"
Unless you have an answer as to what it is that scientists who oppose evolution are not allowed to publish, you should refrain from making an ass of yourself.
A life?
Somehow this is all doubtful.
You're not getting off taht easily.
YOU didn't have teh good grace to 'mind your own business', yet you want others to leave you alone?
Sorry pal, doens't work that way.
"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
Are you her paid myrmidon? Unless you have something to add other than insults, bugger off.
Grade: Failing.
And yes, get a life.........
"Just seeing how you handle the kind of insults you dish out.
Grade: Failing.
And yes, get a life.."
Just seeing how you and your little gang handle the kind of debate that is required here.
Grade: F-
Find an argument.
That is entirely different than what you claim I said, isn't it? I believe, as far as what is published, that not everything IS published that is credible, if it doesn't go along with a particular agenda with the editors/board of the journals that print evolution studies (i.e., one way evolution ideas). But, there is not a 100% consensus on evolution, is there?
Evolution is a fact. The Theory is how it happened. You, specifically, said it was just theory/speculation.
The defintion of evolution has evolved: I was taught evolution was a theory. Of recent history, it has become to be defined as a fact.
I already submitted a term paper to you regarding my "slash" mark and use of the word "or" within the same paragraph, but you claim I'm a liar and you know my intent better than I....that what I wrote I really didn't mean, never mind the fact that my college degree is in English and I graduated Summa Cum Laude.
Did you know taht debate constitutes honest conversation, point and counter-point?
Your posts here have been far from debate.
You've been a baiting abusive poster here.
And contradictory too:
"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
A thin skinned bully who can't take his own medecine.
Funny, you've been the one insulting everyoe.
And no, I won't bugger off.
Perhaps you should...:
"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
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