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.
Didn't you ever see 'The Fly'?
There are no dissenting theories. Perhaps you are unaware of the meaning of the word "theory"? Hint: it requires evidence.
Of course. There are always dissenting beliefs. But until those beliefs can be expresses in scientific terms, until they can become hypotheses, they don't count. That's the way science works - not all notions are equal.
Once again, where are "the HUNDREDS of names/links to various scientists' dissenting opinions and studies, posted on FR on what must be thousands of posts and on a multitude of threads, which put forth dissenting theories/opinions/arguments/conclusions" that don't rely on creationism or pseudo-science?
As I previously posted to another poster, I do not have at my recall examples for the various instances wherein I saw or read articles or scientists names to which I refer. Seeing as how I have no interest in debating my viewpoints concerning evolution, for reasons previously stated, I am also unwilling to go back through years worths of threads and scan the internet to find any such examples, as well.
As I previously posted to another poster, I do not have at my recall examples for the various instances wherein I saw or read articles or scientists names to which I refer.
So your statement that there are "HUNDREDS" was... a wild guess?
I am also unwilling to go back through years worths of threads and scan the internet to find any such examples, as well.
I get it.
You'll make a bold statement about some conspiracy to supress competing theories, but you can't list even one single solitary theory that is being oppressed.
That tells us all we need to know about you. Thanks.
I did do a search on the subject of scientific journals refusing to publish counter-evolutionary articles...lots of things did come up, way too many for me to read now, what with the Thanksgiving rush coming upon us(at least for me)...so will have to leave reading these articles until a later date....just had time to skim through some of these articles...
Some articles just appear to be on different blogs, and give no real evidence of specific cases where counter-evolutionary articles were refused publication, rather it was just some posters opinion...however there was one article which discussed this, saying that the counter-evolutionary articles were not published, because there were no scientific evidence presented with the article...it intimated that where as the evolutionists were required to provide scientific evidence of everything they said, the counter-evolutionists did not feel it was required of them to produce the same amt of scientific evidence...which does seem as an appropriate reason for not publishing a particular counter-evolutionary article...
Scientific evidence does seem to be the basis for deciding which articles to print...
I am sure, tho, as I research these articles, I will find other differing opinions...but its not opinions that I am after, I would like to see the evidence...
Your opinions are that the HUNDREDS of names/links to various scientists' dissenting opinions and studies, posted on FR on what must be thousands of posts and on a multitude of threads, which put forth dissenting theories/opinions/arguments/conclusions than the ones your and those in your "ping list/group" (i.e., FR evolutionarians) hold, are NOT CREDIBLE.http://www.freerepublic.com/focus/f-chat/1525629/posts?page=252#252
I'm asking you to defend the statement that there are HUNDREDS of links to various dissenting opinions and studies that do not rely on either creationism or other forms of pseudoscience.
You have consistently refused to provide any evidence whatsoever to support this assertion.
Make snarky remarks all you like, my friend. Won't change the fact that you have been revealed.
For at least the third time, I am unwilling to waste my time posting to this thread any of the articles/scientists names I've seen, on FR or on the web, which were kept from being published in science journals because their conclusions/ideas/agenda dissented from the agenda held by a journal's editors/board members.
That you call them wild accusations is of no concern to me whatsoever, as you and others like you on this thread have made wilder ones against me, which is obvious to anyone of sound mind perusing this thread.
Almost all of you have revealed the truth of my words, as well, as to the obnoxious, rude, and abusive behavior found on these threads and why I stay away from them, with the exception of this particular thread, to which I was asked to post.
Out of 400 + posts, almost all comments directed to me, or about me from you and those like you, are the direct result of my stating that I did not want to offer a specific opinion and because of obnoxious posters prevalent on these threads.
Hello.
Nice to know somebody still wants to fight.
After TWO DAYS.
Best to just walk away dude.
Very familiar with trolls.
Like the one who decided to keep fighting for two days despite repeatedly being told "I don't want to fight", and who when repeatedly shown his own contradictory statements told me "Last warning, don't post to me again!"
Already done. Thanks!
Welcome.
See you in humor threads where we can relax.
Laters, have fun, FReegards.
yes, like that one, especially.
This isn't a humor thread? Dang. Could have fooled me.........
uh oh....now you've done it. : )
ping
You beat me to the ping
Thank you! Now I can see what all the excitement was about that I missed.
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