Top Stories - Posted by Pam Jahnke-Michigan State on Thursday, March 24, 2011 9:35 - 3 Comments 
(2 votes, average: 5.00 out of 5)
Loading ...
(2 votes, average: 5.00 out of 5) Loading ...Sometimes it’s survival of the less fit
When it comes to survival of the fittest, it’s sometimes better to be an adaptable tortoise than a super fit hare. (Credit: BEACON)
MICHIGAN STATE (US) — Using cloned E. coli bacteria, researchers replayed evolution over and over and uncovered an unexpected twist on survival of the fittest: Sometimes it’s better to be more adaptable.
Share this article
Email
Republish this article
The text of this article by Futurity is licensed under a Creative Commons Attribution-No Derivatives License.
In this week’s Science magazine, Richard Lenski, a Michigan State University professor of microbiology and molecular genetics, and colleagues report that more adaptable bacteria oriented toward long-term improvement prevailed over competitors that held a short-term advantage.
The discovery that the less-fit organisms overtook their in-shape counterparts surprised the researchers at first. But it turns out to work something like a game of chess.
“In games it makes sense to sacrifice some pieces for an eventual winning move,” says Lenski. “The eventual winners were able to overcome their short-term disadvantage over the course of several evolutionary moves by producing more beneficial mutations.”
While Darwin’s theory of natural selection has been confirmed by a great deal of other research, it has never before been observed directly for so many generations and in such detail as Lenski’s long-term experiment has afforded.
Lenski has recorded evolutionary change over 52,000 generations of bacteria grown during nearly 25 years. He and his team recently revived a frozen population of E. coli and compared the fitness and ultimate fates of four clones representing two genetically distinct lineages.
One lineage eventually took over the population even though it had significantly lower competitive fitness than the other lineage that later went extinct.
By replaying evolution over and over with the clones, the researchers showed that the eventual winners likely prevailed because they had greater potential for further adaptation.
“In essence, the eventual loser lineage seems to have made a mutational move that gave it a short-term fitness advantage but closed off certain routes for later improvement,” Lenski says. “And the dead-end strategy allowed the eventual winners to catch up and eventually surpass the eventual losers.”
Collaborators include scientists at the University of Michigan, University of Texas, and University of Houston.
Lenski’s research is supported by the National Science Foundation, the Defense Advanced Research Projects Agency, and by MSU AgBioResearch.
More news from Michigan State: http://news.msu.edu/
Please wait
3 Comments
NewEnglandBob
Dutsj
The phrase “survival of the fittest” is often misunderstood. “Survival of the best fitting” describes more to the point the central thesis of neo darwinsims .
Interesting. This result parallels an experience I had a number of years ago as a grad student in marine biology playing a game about evolution. The game allowed a few turns to draw cards and evolve your “creature” to the current environment. Then the environment would subtly shift and you had to evolve to the new environment. I figured out right away that our creatures did not spend enough time in a stable environment to make it worthwhile to optimize for that environment. Instead, I made my creature as neutral as possible to the effects of all the environments. This strategy ended up being a winning one, but interestingly, none of the other students could figure out why I kept winning game after game. I did not lose a game until I shared my strategy with another (very frustrated!) student. At that point, luck of the draw became a factor, and this other person finally won a game. I guess the idea that being a “generalist” might provide an advantage is non-intuitive when it comes to evolution!
I don’t care for the title of this article. “less fit” is not the correct term to use here.