They tried it in the 1970's - it didn't work as planned.
Posted on 12/09/2003 7:47:21 AM PST by PatrickHenry
In what has been described as the "perfect experiment," evolutionary biologists at the University of Chicago replaced a single gene in fruit flies and discovered a mechanism by which two different "races" begin to become different species, with one group adapted to life in the tropics and the other suited to cooler climates. The tropical group was more tolerant of starvation but less tolerant of cold. The temperate group was less able to resist starvation but better adapted to cool weather.
The altered gene also changed the flies' pheromones, chemical signals that influence mating behavior. As a result, the researchers show in the Dec. 5 issue of Science, the two groups of flies are not only fit for different environments but may also be on their way to sexual isolation, a crucial divide in the emergence of a new species.
"This study directly connects genetics with evolution," said Chung-I Wu, Ph.D., professor and chairman of ecology and evolution at the University of Chicago and director of the study. For the first time, we were able to demonstrate the vast importance in an evolutionary context of a small genetic change that has already occurred in nature."
"We had the luxury," added co-author Tony Greenberg, Ph.D., a postdoctoral student in Wu's laboratory, "of watching the essential event in Darwinian evolution, the first step in the origin of a new species. We were quite impressed, that this simple alteration played such a dramatic role, both adapting flies to a new environment and changing their sex appeal. Once two groups become sexually isolated, there's no turning back."
The scientists used a new technique to knock out one gene from fruit flies and then replace it with one of two slightly different versions of the same gene.
They focused on a gene called desaturase2 that plays a role in fat metabolism. Flies from Africa and the Caribbean, where there is tremendous competition for food but cold temperatures are not a problem, have one version of ds2. Flies from cooler climates, where there is less competition for food but greater temperature variation, have a smaller, inactive version of ds2.
The same gene plays a role in the production of cuticular hydrocarbons -- waxy, aromatic compounds that coat the abdomen of female flies. A male fly, in a romantic mood, strokes the female's abdomen with his feet, which have sensors that recognize specific hydrocarbons, like a perfume.
In a previous report, Wu's laboratory found most males with the temperate version of the ds2 gene preferred females with the same gene; tropical males preferred tropical females.
"Developing increased cold tolerance was an important step for flies that migrated out of Africa to Europe and Asia," Wu said. The change in pheromones, which altered patterns of sexual attraction, "was a by-product of adaptation to colder weather."
Fruit flies have a migratory history similar to humans. They originated in Africa, spread to Europe and Asia and went on to populate the world. As with humans, there is greater diversity within African flies than between flies from Africa and other continents.
Although fruit flies have been a favorite model for the study of genetics since the early 20th century, recognition of consistent differences between tropical and temperate flies came only in 1995. The discovery, however, "has allowed a lot of analysis of the evolution of adaptive traits," Wu said.
"But this was the first time we have been able to study the process from the very beginning," he added, "to watch the first steps as one species begins to split into two, then seals the bargain by increasing sexual isolation. This is the essence of biodiversity."
Additional authors include Jennifer Moran from the Wu lab and Jerry Coyne of the University of Chicago. The National Institutes of Health and the National Science Foundation funded the study.
Better give him some time; he has to don the surgical glove and pull the evidence outta somewhere.
It would not be a FR evolution debate without VadeRetro spewing insults.
And as far as genes being mentioned in the bible:
Genesis 1:11-12: “And God said, let the earth put forth grass, the herb yielding seed, and the fruit tree yielding fruit after its kind, wherein is the seed thereof upon the earth, and it was so. And the earth brought forth grass, the herb yielding seed and the fruit tree yielding fruit after its kind whose seed was in itself.”
That wonderful genetic code gets copied faithfully, every time.
It goes back to classical mechanics, Newton's day. As if the planets are billiard balls and the mechanical action of the solar system is like a clock where all velocities and positions can be determined for all time by simple calculations. Solar light pressure on asteroids has been measured using radar, and that wasn't in the original theory, which was a theory. If the solar system is like a clock, that might imply a clock-maker to push the analogy beyond utility. But the solar system isn't like a clock: future positions can't be computed even if the numbers were taken out to an infinitude of decimal places. It's a stochastic process. On top of that organic processes are not stochastic at all, the creatures doing things of their own volition.
They tried it in the 1970's - it didn't work as planned.
This is REALLY funny. PatrickHenry considers this comment "denial"
Like I said: Being unable to intellectually respond to any of the responses, PatrickHenry is forced to merely list them
Creationists don't believe in genes because they aren't mentioned in the Bible.
Yeap, somebody is pulling "evidence" out of their lower colon.
It really was like arguing with a creationist. He's young and an otherwise smart person so I think he'll eventually outgrow this. Some others are beyond help...
Simply incredible. Talk about having your head buried in the sand.
But, again, I have never heard anyone deny the existance of genes. Could you provide any supporting, or confirming evidence of gene denial?
I have never heard anyone relate any of this, or anything even close.
As always, for all of us, there are others here that would have me believe these are nothing more than your advocacy of unenlightened prejudices. I certainly do not want to believe that is the case.
Please provide any supporting, or confirming examples of these definitions.
What?!!
Forgive my slowness, but; could you walk me through that in a little more detail?
Isn't the poster recognizing, and even complimenting, the existance of genes here?
Could you provide supporting evidence for this claim or did you too pull this out of your lower colon?
Who needs logic and reason or even supporting evidence when all you have to do is claim victory and do a victory dance....amazing!
The evolutions are reaching deep into their collective lower colon today.
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