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.
He reads "Science Journals"?
It needed cleaning anyway. Don't forget the Pine-Sol.
"He reads "Science Journals"?"
Not bloody likely.
That's b_sharp's job.
Crying-baby-Creationist placemarker.
Are you maroon? A new ethnicity is born.
"Are you maroon? A new ethnicity is born."
He's speaking Bugs Bunny.
When you take unexcused absences you pay the price. After you get back you'll have to stand in line and wait.
Too old to wait. You don't want to be in line ahead of me.
I won't be in line. I have my eye on a heated toilet seat and a new color scheme - very spiffy. Then there is the indirect lighting for reading the newest evil literature. And I am considering a pasta wallpaper.
Frightened, I would say. A candidate for my experimental therapt endocrinotomy.
I didn't back up what? The reason why I don't post my ideas on these threads? To restate: "I have my own ideas but, just like everyone else, since no one was around, it's all theories/speculation." That is and was my opinion; there's nothing to back up.
As to why I don't post my specific ideas on these threads, you have already proven my point (and, backed them up with your own behavior): You are representative of the numerous obnoxious posters on these threads. The condescending remarks are not even limited to those who express their ideas, you direct nasty comments to those who won't state their specific ideas.
No scholarly person would define debating as belittling, demeaning others, arguing for the sake of arguing, and/or name-calling. As there are very, very few who attempt to do otherwise, and keep it to some kind of intelligent high ground, it's nothing more than an exercise in futility. Generally, the mob mentality takes over in these threads. Unfortunately, your posts are the general rule rather than the exception.
Now look. You scared him away. He would have been infinitely more interesting under a microscope coverslip.
I would have to yes there are such things as shapeshifters!:)
To which question I gave a specific answer: Though you quote and comment on my second sentence:
And, finally, you post yet more snarky comments:
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.
You post a snarky comment to me right off the bat, assuming that I am stupid and believe that theories and speculation are one and the same, even though I later used the word “or” between “theories” and “speculation”, which any educated person would understand the writer is showing an automatic designation of those words as separate ideas:
I didn’t state any specific "idea" when I mentioned the Scientific Method, only that credible science must use the scientific method. I stated that MUCH of the theories/speculation cannot be proven using the scientific method. And that is how science operates: it’s a theory until/unless something can be scientifically proven using the scientific method.“A scientific theory is not *speculation*. I am sure you have already been told this already. There is no hierarchy from theory to *law*. Theory is the last step.
"Credible science includes the scientific method---the ability for anybody to reproduce the "test" and have the same effect."
you leave out my final sentence:And that's not possible with much of these theories or speculations.
The word “and” is important, as it is goes back to the previous sentence. It is completing a thought contained in the previous sentence. The word “and” is a conjunction. In that sentence, the word “much” is used, and it is also important, as it QUALIFIES theories or speculations, placing a number on them, as in MUCH (not all, not none, but much).That assumes you are not talking about an historical science. Evolution IS tested though, every time a fossil is exhumed and every time two genomes are compared. Natural selection is tested all the time in the lab, with repeatable results. Common descent is tested and affirmed with tests on ERV's in humans and other primates. You need to brush up on your science education.
All scientists are not in consensus on all things evolution and it is disingenuous for you to claim otherwise.
I did not come to this thread to state anything other than a direct response to my friend, who initially asked my thoughts. You have been rude and obnoxious from your FIRST post; and that is also disingenous for you to begin to claim otherwise.
This is not evolution - it is speciation. The fly didn't become a butterfly, it became a new species of fly. Not a big deal. It has been going on since the beginning of time. This is how and why there are variations of the created kinds.
Now, knock it off.
FOTFLMHO
what he don't realized that he is talking to shark and snakes and yellow stuff and paranoid ghost, fuzzy bugs etc!
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