In Evolution Theory, The Tortoise is Better Than the Hare

A Michigan State University evolutionary biologist has suggested that it is sometimes better to be an adaptable tortoise than a fit hare when it comes to survival of the fittest.

Richard Lenski and colleagues found bacteria that evolve slowly are more likely to survive in the long term than those evolving more quickly.

The discovery that the less-fit organisms out-survived 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," said Lenski.

"The eventual winners were able to overcome their short-term disadvantage over the course of several evolutionary moves by producing more beneficial mutations," he added.

The researchers 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," said Lenski.

"And the dead-end strategy allowed the eventual winners to catch up and eventually surpass the eventual losers," he added.

The study appears in the new issue of Science.

Source: ANI