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.
darks....you familiar with trolls?
My, you guys were really getting it on last night. Sorry I missed the debate! I love crawling around in the mud. LOL!
"Why can't we all just get along?..." I think we are all just one happy species and we haven't speciated or devolved yet???? Huh? lol
Hope everyone has a good day.
devolved? some haven't yet evolved first. : )
You have a nice one, too, phantom.
My charge: I find it more than preposterously amusing that the cumulative posts numbering in the thousands, which are contrary to, or dissent from, your agenda/belief system/ideas/opinions, have been and continue to be dismissed as not credible.
Given that not a single one of those posts contain a single scrap of empirical evidence, your amusement is misplaced.
Perhaps you're familiar with the Bandwagon Fallacy, sometimes known as appeal to popularity? Just because there have been many Internet sites devoted to something doesn't give that something any validity by itself. Heaven knows, there are websites devoted to Democrat foreign policy - doesn't mean that policy exists.
Science is worthless without empirical evidence. No creationist has ever been able to supply even the slightest shread. Kindly look at all the posts you mention, this volume of creationist thought, and find just one with actual empirical evidence to support the author's assertion. It's not our job to do you homework for you - the person makign an assertion must supply the evidence to it back up. Failing to do so while still claiming that there must be some evidence out there, suppressed by the vast scientific conspiracy, will expose you to ridicule, yes.
If I claimed to be a big-league player but couldn't swing the bat, I'd be open to ridicule. If I claimed to be a mathematical genius but had to count on my fingers and toes, I'd be open to ridicule. If I claimed to be ten feet tall, but have to stand on a stool to reach the top shelf, I'd be open to ridicule. And yes, if I claimed to have a valid scientific theory but couldn't supply any empirical evidence, then I'd be open to ridicule.
It's not unfair to roll one's eyes at those who insist that the rules of a discipline don't apply to them because they're somehow "special".
I bet Toads and Frogs might have a word to say about race-mixing?!
Huh? What you say? All your base are belong to us!
Now I know you are getting down and dirty! LOL!
It's not unfair to roll one's eyes at those who insist that the rules of a discipline don't apply to them because they're somehow "special".
Where did I state, EVER, my criticisms were pertaining to beliefs/scientists espousing "creationist" thought? Those are YOUR divine assumptions, as well as another's. I have repeatedly and clearly stated: there is a certain "agenda/belief system/idea/opinion" as pertains to pro-evolution posters in FR and those which are published by the Science Journal. I have never stated, nor intimated, that I am a creationist, nor that I disbelieve in evolution. Because the diviners on this thread make that claim, neither makes it true or factual.
I'd say it's quite "fair" to roll one's eyes when, in the course of this thread:
1. And even with your post, words, beliefs, and intent are attributed to me that I have never made (i.e., "creationist")
2. What I state is twisted into something I didn't state (i.e., "one way evolution ideas" becomes "anti-evolution", by several on this thread)
3. Words I state are left out so as to distort my intent (the use of the slash mark and the word "or" on my very first post, and what followed in thought with the word "And").
4. My statements are accepted neither on their face, nor later in clarification...rather, other's divined belief and negation of my intent takes place over my own statements.
The name-calling, baiting, and sundry other attacks against me have resulted from the diviners on this thread who refuse to accept, as fact, that the obnoxious behaviors which are exhibited on these kinds of threads are not conducive to "debate," rather, there is a mob mentality which exists to extinguish discourse or intelligent inquiry/dissent, even when reasons are given as to why someone may (and has) refused to state, with specificity, what they believe concerning evolution (though a diviner even claims my specific beliefs concerning evolution were actually stated on this thread---Lakeshark knows that is yet another lie about me, as my SPECIFIC opinion WAS told to him, a couple days ago. You may direct that question to Lakeshark as to whether I, in fact, did so, and whether or not what I said to him, or anything resembling what I said to him, can be found anywhere on this thread of 400 + posts).
And for what has gone on, there's plenty of reasons to roll one's eyes.
Kindly re-read the quote from me in your post.
No creationist has ever been able to supply even the slightest shread. Kindly look at all the posts you mention, this volume of creationist thought, and find just one with actual empirical evidence to support the author's assertion.
Where did I call you a creationist?
I never did. You referenced the creationist pseudo-science found on this thread and implied that surely some of it was credible. I answered that none of it actually contained evidence. I did say that the pseudo-science was posted by creationists, which is true.
And you still haven't responded to that same basic fact - none of the claims you referenced have ever been supported by a single shread of empirical evidence.
But go ahead - change the subject. It's easier than actually backing up your statement that there's evidence out there.
As a follow-up, I'm sorry if you feel tarnished by being grouped in with creationists.
But if you're going to spread the nonsense that there is somehow a scientific conspiracy to suppress evidence that contradicts evolution, you're the one casting your lot in with theirs.
sorry I will always regard that phrase with utter contempt and disdain!
I don't know how much stronger I can say it!
It aroues unpleasant feeling of my dyslexic days which has embrassed me and caused much pain!
Cite the post where I ever referenced CREATIONIST, or pseudo-science.
Where did I ever state that there is "evidence that contradicts evolution."
Sorry, I knew that, that's why I said it. Just kidding. Didn't mean to upset you :( But you invoked the 'What you say' phrase. 'All your base' follows naturally. Just a spoof on for'ners who make stupid video games. And believe me, my house is run amuk with video games.
Btw, dyslexics are known to be the most brilliant and creative people around. ;)
"Sorry, I knew that, that's why I said it. Just kidding. Didn't mean to upset you"
add that with an abusive mother who loved to mock!
"But you invoked the 'What you say' phrase"
what you say is a colonialism...
Kindly show me which posts among "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 you reference aren't creationist in origin.
If you don't think that there is any evidence that contradicts evolution, then we have no dispute.
Without evidence to support them, there are no "dissenting theories" after all.
This does NOT state, nor even infer, that I was targeting/naming creationist, or pseudo-science.
XenuDidit placemark
Where are they, all these dissenting opinions on these boards that don't rely on either of these?
That is not true; because there is not a 100% concensus on everything evolution, there is dissenting theories/ideas/beliefs, regarding various aspects of evolution.
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