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Austin Cline

Evolution in Action: Bacteria Evolve New Trait

By July 12, 2008

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Evolution Deniers like to claim that naturalistic, materialistic evolution cannot account for the appearance of completely new traits according to Deniers, only slight modifications of old traits is possible. This isn't true, of course, as the process of evolution can be shown to provide for new traits all the time. It is nice, however, to see a clear and unambiguous example of this because such examples make it easier to demonstrate that not only are Evolution Deniers wrong, but are in fact engaging in substantial intellectual dishonesty for pursuing arguments that are so obviously false.

Recently, biologist Richard Lenski of Michigan State University discovered that one of the populations of E. coli bacteria which he has been cultivating for 20 years developed a rare and unexpected new trait. His 12 populations have been reproducing for more than 44,000 generations now and every 500 generations, he saves a sample so he can "replay" their development to see what happened.

But sometime around the 31,500th generation, something dramatic happened in just one of the populations the bacteria suddenly acquired the ability to metabolise citrate, a second nutrient in their culture medium that E. coli normally cannot use. Indeed, the inability to use citrate is one of the traits by which bacteriologists distinguish E. coli from other species. The citrate-using mutants increased in population size and diversity.

"It's the most profound change we have seen during the experiment. This was clearly something quite different for them, and it's outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting," says Lenski. ...

Lenski's experiment is also yet another poke in the eye for anti-evolutionists, notes Jerry Coyne, an evolutionary biologist at the University of Chicago. "The thing I like most is it says you can get these complex traits evolving by a combination of unlikely events," he says. "That's just what creationists say can't happen."

Source: New Scientist

Previously, most of the evolutionary developments had been relatively minor and predictable like evolving larger cells and faster growth rates. The evolution of the ability to metabolize citrate, however, wouldn't have been predicted because it's so unusual. It's just such improbable developments, though, which Evolution Deniers insist aren't possible through a completely natural, materialistic process. What can they argue here, though? Can they really argue that their god decided to intervene and alter the genetics of one population in one biologist's laboratory experiment? That strikes me as even more improbable.

In addition to demonstrating that new traits can evolve naturally, this also demonstrates just how contingent evolution can be:

...the experiment stands as proof that evolution does not always lead to the best possible outcome. Instead, a chance event can sometimes open evolutionary doors for one population that remain forever closed to other populations with different histories.

Evolving the ability to metabolize citrate is arguably a nice improvement because it allows the E. coli to take advantage of even more nutrition, but it only happened in one of twelve populations. If it's so advantageous, why didn't more evolve this ability by now? The answer is because the best advantages and the best solutions to environmental problems don't always evolve. These twelve populations are like twelve sets of the same population run twelve different times, and in only one of them did this important benefit develop. In the history of life on our planet, there are many missed opportunities and many evolutionary developments which might not have otherwise happened if you rewind the tape of life and play it again, natural history might turn out radically different for no apparent reasons.

Comments
July 12, 2008 at 10:12 pm
(1) Paul Buchman says:

It won’t take long for creationists to find a way to discount this event.

July 12, 2008 at 11:01 pm
(2) Wurdulac says:

Hell, if they follow the same M.O they’ve been following, they won’t need to discount it; they’ll just ignore it (much like transitional fossils).

July 13, 2008 at 5:32 am
(3) The Sojourner says:

I wonder how the ID’ers could wrap their brains around the ever mutating and therefore evolving flu viruses? Flu shots don’t always work because the viruses keep developing resistance to the vaccines, evolution at work. So even with the shot you can get very sick. Would the ID’ers consider this a punishment(one of many)from their god, because we are sinners and he’s p.o.’d at us? How would they explain it? Just a random thought.

July 21, 2008 at 2:51 pm
(4) Drew says:

Thanks for a great article I can cut and paste into my files, for future reference.

July 25, 2008 at 11:04 pm
(5) Jason says:

You even said in this article that its a mutation! These are your words and I QOUTE ( The citrate using MUTANTS increased in population size and diversity. )Like kind produces like kind what will you say if these mutant e-coli die off. whats really funny is this Is this bacteria still E-COLI? it is just like how some people are amune to the common cold? Im still waiting for the non living matter to change into living matter. And for the transitional fossils where are the thousands upon thousands I mean millions upon millions I mean billions upon Billions of these so called fossils. So Im willing to bet that this bacteria still produces bacteria? The question is is this bacteria still E-COLI? It still is E-COLI WOW E-COLI turns into E-COLI o my. O my i must have evolved because I grew facial hair!

July 27, 2008 at 12:30 am
(6) John K says:

“You even said in this article that its a mutation!”

Right, what else would you call a bacteria that has mutated into a new species or strain?

“Is this bacteria still E-COLI?”

That’s a very good question, since bacteria do not reproduce sexually and species are not identified as populations of interbreeding individuals. First, we need to determine which method of classification identification we will use. What do you think, serovar? biovar? morphovar? isolate? And since a mutated strain will not produce one of type it mutated from, does it matter?

“Im still waiting for the non living matter to change into living matter.”

Which definition of “living” are you using? Do you consider viruses to be alive?

“…i must have evolved because I grew facial hair!”

Or perhaps your family has yet to evolve.

October 25, 2011 at 2:50 pm
(7) Echo says:

“Or perhaps your family has yet to evolve.” ROFL!

Evolution Deniers are brainwashed, pure and simple. I wonder if there are neuronal cell modifications happening over time and if so – what they will evolve into. Scary!

August 20, 2008 at 10:07 am
(8) GV says:
June 18, 2009 at 8:31 pm
(9) jason says:

You are a fool. This is bacteria’s God-given ability to survive. Read Dr. Georgia’s explanation of mutating bacteria on the Answers website.

November 5, 2009 at 3:06 pm
(10) Jess says:

creationism is a hoax. there is too much out there now that disproves it while also proving evolution. e coli bacteria EVOLVED. thats called evolution boys and girls. science and fossils have shown that bacteria were one of the first life forms on earth because of an atmosphere that had just the right amounts of nitrogen, oxygen, carbon, and hydrogen. science also says that as earth began to change, become more oxygen rich, and a few other changes to the planet, eukaryotic organisms were being created through the transfer of genetic material, and eventually came more complex organisms. the inian space research organization discovered in 2001 that clumps of living cells were falling from space. they were found as high as 41 km above the earths surface. the tropopause, only 16 km above us, is an area that above which no air from anything lower could normally be transported. so, the living cells were not from earth. HA.

November 16, 2009 at 8:47 am
(11) rex says:

The bacteria have not evolved into anything else people. They are still bacteria. I’m sorry evolutionists but you have a long way to go before you can prove your religion. Show a mechanism than will transform a bacteria into a plant cell or an animal cell. Show me how bacteria arose in the first place. Show me any MACRO evolutionary process that is undisputed. That’s right, there aren’t any. I say evolution is a HOAX.

November 16, 2009 at 9:20 am
(12) Austin Cline says:

The bacteria have not evolved into anything else people. They are still bacteria.

Bacteria don’t have to evolve into “something else” in order to evolve.

Do you comprehend what evolution is?

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