Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Genetic evidence for punctuated equilibrium
The Scientist ^ | 06 October 2006 | Melissa Lee Phillips

Posted on 10/07/2006 9:08:18 AM PDT by PatrickHenry

Evidence for punctuated equilibrium lies in the genetic sequences of many organisms, according to a study in this week's Science. Researchers report that about a third of reconstructed phylogenetic trees of animals, plants, and fungi reveal periods of rapid molecular evolution.

"We've never really known to what extent punctuated equilibrium is a general phenomenon in speciation," said Douglas Erwin of the National Museum of Natural History in Washington, D.C., who was not involved in the study. Since its introduction by Stephen Jay Gould and Niles Eldredge in the 1970s, the theory of punctuated equilibrium -- that evolution usually proceeds slowly but is punctuated by short bursts of rapid evolution associated with speciation -- has been extremely contentious among paleontologists and evolutionary biologists.

While most studies of punctuated equilibrium have come from analyses of the fossil record, Mark Pagel and his colleagues at the University of Reading, UK, instead examined phylogenetic trees generated from genetic sequences of closely related organisms.

Based on the number of speciation events and the nucleotide differences between species in each tree, the researchers used a statistical test to measure the amount of nucleotide divergence likely due to gradual evolution and the amount likely due to rapid changes around the time of speciation.

They found statistically significant evidence of punctuated evolution in 30% to 35% of the phylogenetic trees they examined. The remaining trees showed only evidence of gradual evolution.

Among the trees showing some evidence of punctuated equilibrium, the authors performed further tests to determine the size of the effect. They found that punctuated evolution could account for about 22% of nucleotide changes in the trees, leaving gradual evolution responsible for the other 78% of divergence between species.

Pagel and his colleagues were surprised that rapid evolution appears to contribute so much in some lineages, he said. "I would have maybe expected it to be half that much," he told The Scientist.

The researchers also found that rapid bursts of evolution appear to have occurred in many more plants and fungi than animals. Genetic alterations such as hybridization or changes in ploidy could allow rapid speciation, Pagel said, and these mechanisms are much more common in plants and fungi than in animals.

"Their result is pretty interesting, particularly the fact that they got so much more from plants and fungi than they did from animals, which I don't think most people would expect," Erwin told The Scientist.

However, it's possible that the analysis could be flawed, because the authors didn't take into account extinction rates in different phylogenetic trees when they determined the total number of speciation events, according to Douglas Futuyma of the State University of New York at Stony Brook, who was not involved in the study. But "they've got a very interesting case," he added. "I certainly think that this warrants more attention."

According to Pagel, the results suggest that other studies may have misdated some evolutionary events. Dates derived from molecular clocks assumed to have a slow, even tempo will place species divergences too far in the past, he said, since genetic change assumed to take place gradually may have happened very quickly.

"These kinds of events could really undo any notion of a molecular clock -- or at least one would have to be very careful about it," Futuyma told The Scientist.

Well known evolutionary mechanisms could account for rapid genetic change at speciation, Pagel said. Speciation often takes place when a population of organisms is isolated, which means that genetic drift in a small population or fast adaptation to a new niche could induce rapid evolutionary change.

=======
[Lots of links are in the original article, but not reproduced above.]


TOPICS: Culture/Society; Philosophy
KEYWORDS: crevolist; junkscience; ntsa; obsession; punctuatedidiocy; speculation
Navigation: use the links below to view more comments.
first 1-2021-4041-6061-80 ... 461-471 next last
Everybody be nice.
1 posted on 10/07/2006 9:08:19 AM PDT by PatrickHenry
[ Post Reply | Private Reply | View Replies]

To: VadeRetro; Junior; longshadow; RadioAstronomer; Doctor Stochastic; js1138; Shryke; RightWhale; ...
Evolution Ping

The List-O-Links
A conservative, pro-evolution science list, now with over 390 names.
See the list's explanation, then FReepmail to be added or dropped.
To assist beginners: But it's "just a theory", Evo-Troll's Toolkit,
and How to argue against a scientific theory.

2 posted on 10/07/2006 9:09:15 AM PDT by PatrickHenry (Unresponsive to trolls, lunatics, fanatics, retards, scolds, & incurable ignoramuses.)
[ Post Reply | Private Reply | To 1 | View Replies]

===> Placemarker <===
3 posted on 10/07/2006 9:10:25 AM PDT by Coyoteman (I love the sound of beta decay in the morning!)
[ Post Reply | Private Reply | To 1 | View Replies]

To: All
Darwin and Punctuated Equilibrium. "PE" was actually predicted by Darwin.
4 posted on 10/07/2006 9:13:35 AM PDT by PatrickHenry (Unresponsive to trolls, lunatics, fanatics, retards, scolds, & incurable ignoramuses.)
[ Post Reply | Private Reply | To 3 | View Replies]

To: All
Help for new visitors to the evolution debate
Another service of Darwin Central, the conspiracy that cares.

If you're interested in learning about evolution, visit The List-O-Links.
If you'd like to understand the concept of speciation, visit Micro-evolution, Macro-evolution, and Speciation.
If you're serious about debating this issue, see How to argue against a scientific theory.

5 posted on 10/07/2006 9:14:51 AM PDT by PatrickHenry (Unresponsive to trolls, lunatics, fanatics, retards, scolds, & incurable ignoramuses.)
[ Post Reply | Private Reply | To 4 | View Replies]

To: PatrickHenry
What laughable, horse manure. More grasping straws in an attempt to prop a theory that is a total failure. Nevermind, how many times evolutionists have made fools out of themselves promoting "evidence" that has ended up being debunked.

Evolution happened so fast it didn't leave any fossil evidence. In fact, the fossil record matches the CREATIONIST MODEL OF THE EARTH -- species appear suddenly and fully formed in the fossil record. Evolution is a religion, accepted on blind faith alone so evolutionists don't need any credible physical evidence.

Of course, there has to be a genetic mechanism by which evolution is possible. There needs to be mechanism by which information can be added to the genetic codes of lower organism in order for the lower organisms to develop into higher forms of life. Mutations are the only means by which that is possible. Yet, mutations are 99% detrimental and not ONE has ever been solely beneficial.

Take all this secular, atheistic propaganda to liberal websites and stopped wasting our time here. Become a liberal if you must, just keep such lies off FR.

6 posted on 10/07/2006 9:16:20 AM PDT by Ol' Sparky
[ Post Reply | Private Reply | To 1 | View Replies]

To: Ol' Sparky
Is there a computer program that you guys are using to auto-generate these pointless stock responses?
7 posted on 10/07/2006 9:19:17 AM PDT by Sofa King (A wise man uses compromise as an alternative to defeat. A fool uses it as an alternative to victory.)
[ Post Reply | Private Reply | To 6 | View Replies]

To: Ol' Sparky
Evolution happened so fast it didn't leave any fossil evidence.

On the contrary, there exists extensive fossil evidence.

Take all this secular, atheistic propaganda to liberal websites and stopped wasting our time here.

How is this "atheistic propaganda"? Are you under the mistaken impression that all who accept the theory of evolution are atheists, or do you know better yet simply choose to lie?
8 posted on 10/07/2006 9:20:30 AM PDT by Dimensio (http://angryflower.com/bobsqu.gif <-- required reading before you use your next apostrophe!)
[ Post Reply | Private Reply | To 6 | View Replies]

To: Dimensio

Placemarker


9 posted on 10/07/2006 9:22:39 AM PDT by Jaguarbhzrd
[ Post Reply | Private Reply | To 8 | View Replies]

To: Sofa King; PatrickHenry
Is there a computer program that you guys are using to auto-generate these pointless stock responses?

It is a reflexive incantation they chant whenever they are overcome by the fear that a hob-goblin is about the "get them." Devoid of facts or evidence, and evincing a deep, profound primordial fear, they have no more significance than an expulsion of flatus in the face of a gale wind.

10 posted on 10/07/2006 9:32:06 AM PDT by longshadow (FReeper #405, entering his ninth year of ignoring nitwits, nutcases, and recycled newbies)
[ Post Reply | Private Reply | To 7 | View Replies]

To: Ol' Sparky
Evolution happened so fast it didn't leave any fossil evidence. In fact, the fossil record matches the CREATIONIST MODEL OF THE EARTH -- species appear suddenly and fully formed in the fossil record. Evolution is a religion, accepted on blind faith alone so evolutionists don't need any credible physical evidence.

Oh, yes. That would be the scientific theory that holds that men were made out of mud and women out of ribs, that languages came about when people tried to make a really tall building and that all living land animals are descended from those that lived on a boat about 5000 years ago.

11 posted on 10/07/2006 9:38:47 AM PDT by elmer fudd
[ Post Reply | Private Reply | To 6 | View Replies]

To: longshadow

There is no evidence!
There is no fossil record!
It's all been debunked!

12 posted on 10/07/2006 9:43:25 AM PDT by PatrickHenry (Unresponsive to trolls, lunatics, fanatics, retards, scolds, & incurable ignoramuses.)
[ Post Reply | Private Reply | To 10 | View Replies]

To: PatrickHenry

Syncopated Prevarication


13 posted on 10/07/2006 9:46:46 AM PDT by RoadTest (Remove not the ancient landmark, which thy fathers have set. -Proverbs 22:28)
[ Post Reply | Private Reply | To 1 | View Replies]

To: elmer fudd

"Oh, yes. That would be the scientific theory that holds that men were made out of mud and women out of ribs, that languages came about when people tried to make a really tall building and that all living land animals are descended from those that lived on a boat about 5000 years ago."

Boy! Did you read that wrong. Go back and read Genesis again, more carefully this time.


14 posted on 10/07/2006 9:47:49 AM PDT by RoadTest (Remove not the ancient landmark, which thy fathers have set. -Proverbs 22:28)
[ Post Reply | Private Reply | To 11 | View Replies]

To: elmer fudd
Oh, yes. That would be the scientific theory that holds that men were made out of mud and women out of ribs, that languages came about when people tried to make a really tall building and that all living land animals are descended from those that lived on a boat about 5000 years ago.

No, no, he means the one where the first man was made from an ash tree and the first woman from an alder.

Wait ... or does he mean the pixie version?

15 posted on 10/07/2006 9:49:38 AM PDT by balrog666 (Ignorance is never better than knowledge. - Enrico Fermi)
[ Post Reply | Private Reply | To 11 | View Replies]

To: Ol' Sparky

Hey, Sparky, here's the deal: I'll help you burn all the Darwinist books and papers if you bring the phlogiston.


16 posted on 10/07/2006 9:50:52 AM PDT by BlazingArizona
[ Post Reply | Private Reply | To 6 | View Replies]

To: Ol' Sparky
Become a liberal if you must, just keep such lies off FR.

I have a question for everyone here. Does believing in Evolution mean you cannot be a Conservative or even a Republican?

I have to admit, I sometimes feel like I belong to no party. For me Democrats are too close to socialism (or worse) for my tastes and yet I find on FR that so many people feel that if you believe in Evolution, you are not a Conservative. I don't have anything against Creationists except they wish to push their ideas off on our children as Science.

I cannot fully support a party that wishes to put ID into schools and I am wondering how do others out there deal with this dilemma. (Sorry if this has been asked before).

17 posted on 10/07/2006 10:00:03 AM PDT by trashcanbred (Anti-social and anti-socialist)
[ Post Reply | Private Reply | To 6 | View Replies]

To: PatrickHenry
You can bet certain people will grab that Futuyma quote on molecular clocks without ever processing the rest of the article into their heads.
18 posted on 10/07/2006 10:02:08 AM PDT by VadeRetro (A systematic investigation of nature does not negotiate with crackpots.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Ol' Sparky

"Take all this secular, atheistic propaganda to liberal websites and stopped wasting our time here. Become a liberal if you must, just keep such lies off FR."




My goodness. Science is neither liberal or conservative. It's just science. It's clear that you do not understand the original post.

There are ways to disagree that don't involve ugly language and name-calling. I suggest you learn some of those ways and stop disrupting these threads.


19 posted on 10/07/2006 10:03:03 AM PDT by MineralMan (Non-evangelical Atheist)
[ Post Reply | Private Reply | To 6 | View Replies]

To: trashcanbred

The folks who equate the theory of evolution with liberalism are the same folks who think that conservatism is equal to pentacostal Christianity.

There is nothing in conservatism that opposes evolution. There is nothing in conservatism that opposes the idea that things were created.

Conservatism is a political concept, not a religious or scientific concept.

Those who attempt to assign political beliefs to those who believe one thing or another regarding science are foolish and wrong.


20 posted on 10/07/2006 10:06:49 AM PDT by MineralMan (Non-evangelical Atheist)
[ Post Reply | Private Reply | To 17 | View Replies]


Navigation: use the links below to view more comments.
first 1-2021-4041-6061-80 ... 461-471 next last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson