Evolution As Experimental Science
June 3rd, 2008 midwifetoad Posted in News |
From Science News via Dispatches From the Culture War, we have this news.
Science News has a report on a very cool experiment done by Dr. Richard Lenski at Michigan State (Lenski is also with the Digital Evolution Lab at MSU, along with Rob Pennock and Wes Elsberry, but this is an experiment with real bacteria, not artificial organisms). This is a really cleverly designed test of how a mutation that does not confer a survival advantage can later be coopted by a second mutation that can be selected for.
Lenski’s team watched 12 colonies of identical E. coli bacteria evolve under carefully controlled lab conditions for 20 years, which equates to more than 40,000 generations of bacteria. After every 500 generations, the researchers froze samples of bacteria. Those bacteria could later be thawed out to “replay” the evolutionary clock from that point in time.
After about 31,500 generations, one colony of bacteria evolved the novel ability to use a nutrient that E. coli normally can’t absorb from its environment. Thawed-out samples from after the 20,000-generation mark were much more likely to re-evolve this trait than earlier samples, which suggests that an unnoticed mutation that occurred around the 20,000th generation enabled the microbes to later evolve the nutrient-absorption ability through a second mutation, the researchers report in the Proceedings of the National Academy of Sciences.
Check out the links.
June 7th, 2008 at 4:30 pm
Here is what Otto Schindewolf had to say about experimental evolution. Remember this was in 1950 but in my opinion is just as valid today as it was then.
“Many recent authors have spoken of EXPERIMENTAL EVOLUTION; there is NO SUCH THING. Evolution, a unique historical course of events that took place in the past, is not repeatable experimentally and cannot be investigated in that way.”
Basic Questions in Paleontology, page 311. (the words in caps were in italics in the original).
The experiments described have nothing to do with evolution as the bacteria are still E. coli and, in my opinion, always were and always will be. Creative evolution is a phenomenon of the distant past, a conclusion I share with Pierre Grasse, Robert Broom and Julian Huxley.
“A past evolution is undeniable, a present evolution undemonstrable.”
John A. Davison
john.a.davison.free.fr/
June 8th, 2008 at 12:26 pm
Let the record show that the opinion of the greatest paleontologhist since Cuvier remains unchallenged on the Darwin Central blog.
“A past evoltion is undeniable, a present evolution undemonstrable.”
June 8th, 2008 at 6:53 pm
Let the record show you are a troll who has been banned from every forum you’ve tried to spread your crap on.
June 9th, 2008 at 6:34 am
Carolina guitarman, a cowardly alias obviously. Real men use real names.
Of course I have. That is the best evidence that I am on the right track. You don’t ban kooks, you laugh at them. I have been banished from weblogs and so-called forums for one reason only, fear, fear that I, with my distingished sources, have effectively exoposed the Darwinina fairy tale as the biggest, most enduring hoax in the history if science. So ban me alraady. I’m terrified!
“A past evolution is undeniable, a present evolution undemonstrable.”
http://www.overwhelmingevidence.com/oe/node/550#comment
June 9th, 2008 at 6:35 am
Carolina guitarman, a cowardly alias obviously. Real men use real names.
Of course I have. That is the best evidence that I am on the right track. You don’t ban kooks, you laugh at them. I have been banished from weblogs and so-called forums for one reason only, fear, fear that I, with my distingished sources, have effectively exoposed the Darwinina fairy tale as the biggest, most enduring hoax in the history if science. So ban me already. I’m terrified!
“A past evolution is undeniable, a present evolution undemonstrable.”
http://www.overwhelmingevidence.com/oe/node/550#comment
June 11th, 2008 at 11:28 am
[...] A few days ago we reported on a major new paper dealing with the results of a twenty year laboratory experiment in evolution. During the course of 30,000 generations of E.coli bacteria, a new and significant trait evolved, the ability to use the citrate found in the culture medium as a food source. [...]
June 13th, 2008 at 3:25 am
Big deal!