Posted on 02/24/2006 4:12:32 AM PST by PatrickHenry
Charles Darwin would undoubtedly be both pleased and chagrined.
The famous scientist would be pleased because a study published online this week provides the first clear evidence that natural selection, his favored mechanism of evolution, drives the process of species formation in a wide variety of plants and animals. But he would be chagrined because it has taken nearly 150 years to do so.
What Darwin did in his revolutionary treatise, “On the Origin of Species,” was to explain how much of the extraordinary variety of biological traits possessed by plants and animals arises from a single process, natural selection. Since then a large number of studies and observations have supported and extended his original work. However, linking natural selection to the origin of the 30 to 100 million different species estimated to inhabit the earth, has proven considerably more elusive.
In the last 20 years, studies of a number of specific species have demonstrated that natural selection can cause sub-populations to adapt to new environments in ways that reduce their ability to interbreed, an essential first step in the formation of a new species. However, biologists have not known whether these cases represent special exceptions or illustrate a general rule.
The new study – published online in the Proceedings of the National Academy of Sciences – provides empirical support for the proposition that natural selection is a general force behind the formation of new species by analyzing the relationship between natural selection and the ability to interbreed in hundreds of different organisms – ranging from plants through insects, fish, frogs and birds – and finding that the overall link between them is positive.
“This helps fill a big gap that has existed in evolutionary studies,” says Daniel Funk, assistant professor of biological sciences at Vanderbilt University. He authored the study with Patrik Nosil from Simon Fraser University in British Columbia and William J. Etges from the University of Arkansas. “We have known for some time that when species invade a new environment or ecological niche, a common result is the formation of a great diversity of new species. However, we haven’t really understood how or whether the process of adaptation generally drives this pattern of species diversification.”
The specific question that Funk and his colleagues set out to answer is whether there is a positive link between the degree of adaptation to different environments by closely related groups and the extent to which they can interbreed, what biologists call reproductive isolation.
Funk and his colleagues saw a way to address this question by extending a method pioneered by two scientists in a now classic study of species formation in fruit flies published in 1989. The original method measured the way in which reproductive isolation varies with time. It proved to be very powerful and a number of other researchers applied it to additional species. Funk and his colleagues realized that if they used the results of these studies and added an ecological dimension then they would have an approach capable of measuring the link between natural selection and reproductive isolation.
“We thought that the idea itself was important, that this is a really powerful approach to a very major question,” says Funk, “but we thought that there was no way in the world that we were actually going to get statistically significant results.”
The reason for his doubt was the incompleteness and lack of uniformity of ecological data. “There are all these species out there and so few of them are known in intimate detail, so any kind of ecological characterization, through no fault of ecologists, will be limited in accuracy and precision,” Funk says.
Nevertheless, the researchers decided to do the best they could with the information available. So they collected information from the published literature on three basic ecological variables: habitat, diet and size. Then they used this information to calculate the differences in ecological adaptation between the hundreds of pairs of related species in the original studies.
When they compared these differences in adaptation with the degree of reproductive isolation for each pair and then added them up, the researchers found that the overall association was positive with a surprisingly high level of confidence: The odds that the association is simply due to chance are only one in 250, substantially higher than the standard confidence level of one chance in 20 that scientists demand.
“The fact that the association is statistically significant despite the crudeness of our estimates suggests that the true biological association is very strong,” Funk says. “Darwin’s famous book was called ‘On the Origin of Species,’ but it was really about natural selection on traits rather than species formation. Since our study suggests that natural selection is a general cause of species formation, it seems that Darwin chose an appropriate title after all.”
[Omitted contact info which is at the end of the article.]
I imagine the creationists/ID folks say the same thing about atheist/science zealots.
I am finding that to be one of 'their' modus operandi: they use such illogic that is almost makes sense. They like to use key trigger? words that most people don't quite understand. So while we are trying to figure it out, with the innocent hope that ARE making sense, they claim victory in the argument. Interesting lessons in debating a fool. LOL!
And what do they say about Christians who find the physical evidence for evolution compelling? (that is, a heavy majority of those who support evolution in FR crevo debates)
I think you credit them with too much wits. I just think that my "low probability" argument triggered a Zeno's paradox response from him, because he vaguely remembers that Zeno's paradox is about small quantities.
I haven't the foggiest. I fit that category myself. The main issue that I have is against zealots of either side trying to make an issue of something that will not matter in anyone's life.
Instead, maybe these folks could spend their time thinking about ways to keep people safe from islam, taxes, mad-cow disease, or any other "crisis" du jour.
You could be right. And I also think you are giving him too much credit. I used the term in a post the day before, so maybe he picked it up there. Don't think he would come up with that on his own. LOL!
Been there.
Done that.
Next.
It's just a matter of chemistry.
Let me suggest that some unfortunate individuals look at words, leap to conclusions, and never bother examining the grammatical constructs that link those words into coherent thoughts.
You are close to falling into that category.
Not trying to insult anyone, muawiyah. Couldn't quite follow your reasoning and wasn't quite sure of your alignment. What are your views on natural selection as a driving force?
An atheist buddy of mine used to say that the difference him and us was he believed in just one less god.
Of course, he believed in "the good smoke" as a solution to the world's problems with all the fervor of anyone with a religion.
What you have to understand is that there is a third position that can be taken in the debate that doesn't draw on any of the Evo/Creationist beliefs.
And what is this third position?
When you've let us know what your position is, and what evidence supports it, we'll be able to debate it.
People who claim "not to have a dog in the fight" or to "not believe either creation or evolution" invariably offer up no criticism whatsoever of the creationist position, and pose "difficult questions" (often actually completely standard and endlessly refuted creationist talking points) for evo. Usually after a while it becomes transparently obvious that they are dyed-in-the-wool creationists pretending not to be because they think they gain debating advantage thereby. I'm sure you are not in that category though.
Obviously you haven't read all the posts in this thread. That's why you are talking out of your pockets.
Troll is as troll does.
You've gotta be shittin me!
“The fact that the association is statistically significant despite the crudeness of our estimates suggests that the true biological association is very strong,”
And it might indicate a bias in your crude estimates.
So what do you think of this?:
http://www.freerepublic.com/focus/f-chat/1351793/posts
BTW, if a product of chromosome doubling like the one described turns out to have a desirable characteristic, we can use recombinant DNA technology to move that characteristic into some other plant, e.g. a custard fruit tree maybe ~ probably start pushing out bananas if we did that.
Now, what part of Creationism or Natural Selection does recombinant DNA technology play?
I asked your opinion on that thread for a very specific reason. Your answer is quite illuminating. You protest that you are pro evo, or not a creationist. Maybe so - maybe not.
I don't know what you are, but by your posts the best I can say is that you are at least partially scientifically illiterate, enough so that, as Thatcherite intimated, you could well be a closet Creationoid. I will watch in the future and let the data resolve that issue.
Think about what recombinant DNA technology is and its role, if any, with evolution.
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