Silver-level articleLenski results challenge creationism

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This article may have a content or subject overlap with Richard Lenski and the pages could be merged. You can discuss this here.

In June 2008 the popular science magazine New Scientist printed a story about Professor Richard Lenski's twenty-year project examining the evolution of E. coli.[1] They reported that, as a result of several beneficial mutations, his organisms had acquired the ability to metabolize citrate - or more correctly an ability to transport it through the cell wall prior to metabolizing it. This was an entirely new ability for this species - an increase in complexity provided by a beneficial mutation. This beneficial trait was then fixed in the population by natural selection.

It is also important to notice that before acquiring this ability the bacteria acquired a previous potentiating mutation which, although it was not clearly beneficial at the time, subsequently allowed the descendants of that potentiated group the ability to process citrate after a further mutation. Furthermore frozen ancestors of that group, and only the frozen ancestors of that group, retained the ability to re-evolve that favorable trait.

His group did not use genetic engineering to modify the organism (to design it), it was produced entirely by the evolutionary process.

It is another beautiful example of evolution in action and a fascinating example of potentiating mutations. Although evolution has been demonstrated many times in the past the circumstances surrounding this particular experiment gave it a higher profile.

Ken Ham and Liberty University affiliate Andrew Fabich lied outright about the contents of the paper publishing the results of this experiment during Ham's debate with Bill Nye.

Contents

[edit] General problems for creationists

Creationists come in many different flavors, but the process as outlined above caused problems of one sort or another for almost all of them.

The citrate mutant (center). Not so scary after all.
  • Some creationists deny that any form of evolution occurs and this clear demonstration of the process is an obvious challenge to them.[2]
  • Others will claim that all mutations are inevitably harmful[3] and this beneficial mutation will be hard for them to accept.[4]
  • Yet others claim (erroneously) that the second law of thermodynamics would not allow evolution to generate more complex life forms[5] — yet here we see it doing just that. It is creating new information.[6]
  • Many creationists hold to a false dichotomy of microevolution and macroevolution.[7] By this they claim that organisms may change, for example, their size or color - but that they are unable to develop wholly new traits. (Nevertheless they have never been able to say what the limiting factor could be which allows for "micro" but disallows "macro" mutations.) But again, this experiment really does show life developing new traits.[8] They have developed an ability which they didn't have before. Indeed, one of the defining traits of E. coli has traditionally been its inability to metabolize citrate in the presence of oxygen.[9]

[edit] Problems for intelligent design

Believers in intelligent design maintain that if something "looks" as though it was designed then it was, in fact, designed. Some go no further than that and have no interest in timescales or details and do not see the "design" part as a process. They may well hold other views associated with young-Earth creationism. Others see the "design" part as ongoing process which they try to fit into long-term evolutionary theory in some way or another. Professor Lenski's experiment also causes problems for both these groups.

  • After the beneficial mutation which gave it the ability to metabolize citrate had been fixed in the population the bacteria, they would have looked like organisms "designed" to metabolize citrate. But in this case we have seen that this ability came about as a result of the evolutionary process. As it can be seen that evolution, and not intelligent design, was the driver then it clearly shows that the apparent evidence of design is in no way real evidence of design.
  • This experiment also gives a big problem to more scientifically-minded believers in ID such as Michael Behe. He has claimed that the sheer improbability of a sequence of mutations leading to a change of this type means that evolution simply cannot happen as has been proposed. The fact that Lenski's citrate-eating bacteria have managed a three-mutation step to get where they are in a mere twenty years gives the lie to his objections and sheds significant doubt on the assertions in his book The Edge of Evolution.

[edit] Creationist reactions

Seeing many of their favorite myths so clearly challenged, it is not surprising that creationists would like to undermine Professor Lenski's results. These reactions have ranged from outright rejection and apparent accusation of fraud by more extreme elements, to attempts to minimize the importance of the results by young Earth creationists, to some kind of weird double-think by believers in intelligent design.

[edit] YEC response: it's not what it looks like

Answers in Genesis claims[10] that there are "no additive mechanisms" and that "Instead degenerative events are likely to have occurred resulting in the loss of regulation and/or specificity".

However these responses from AIG would not seem to be wholly consistent with reality as:

  • The organism is doing something it couldn't do before.
  • The organism is now better able to survive in its new environment — where its preferred food, glucose, was limited — so "degenerative events" would seem to be unlikely.

[edit] ID response: yes, it's evolution but it's compatible with ID

Basically, this approach argues that God went in and jiggered with the E. coli's genetics. It provides another wonderful example of why intelligent design isn't science, as it is impossible to disprove that an all-powerful, invisible being did anything, but very easy to say that an all-powerful, invisible being did everything. This "interpretation" of Lenski's findings is in line with some aspects of theistic evolution.

[edit] Conservapedia: outright rejection

The most appallingly unsuccessful attempt to refute, reject and discredit the Lenski study was that made by Andrew Schlafly, the founder of Conservapedia. This resulted in his receiving a remarkable public spanking in what has since been termed and documented on RationalWiki as the Lenski affair‎. Even from the first round of the affair, Schlafly began to lose support from his coreligionists in his efforts, possibly because they felt it was a losing strategy. Several that displayed the most vocal support of him were probably parodists.

[edit] Lenski was the intelligent designer

On Free Republic, a poster named "tongass kid" said of the E. coli developing the ability to process citrate, "So this was done in the laboratory by some intelligent design, not random selection. Fifty years of fruit fly genetic lab experiments on countless number of fruit fly have not created a new species using intelligent design combined with random selection. If it is done in a lab it is intelligent design and not natural selection." [sic] In the following post (post 19 on that same page), a user named "Coyoteman", who has generally been opposed to creationism and intelligent design, seemed to have been confused by the post. [11]

This argument by tongass kid, however, forgets exactly what an intelligent designer is or does; if Lenski had directly modified the genes of the bacteria to absorb citrates, then that indeed would have been an empirical case of intelligent design (and scientists do on occasion modify genes of organisms to bring about certain, intentional results). In this case, however, Lenski merely provided an environment that put pressure on the bacteria to adapt. It was expected that in the time frame of the experiment, the bacteria would be able to marginally increase their efficiency of living in the medium and this was previously demonstrated and published by the time the more prominent and famous report was made. The ability of the bacteria to absorb citrate wasn't an intentional intelligent aim of the experiment. It came as a fair shock to the researchers that the E. coli developed the ability to absorb the citrate medium (described in the popular literature as the bacteria not having enough to eat, so they evolved to eat the plates and cutlery instead).

But of course, since none of those intelligent design proponents are monitoring Lenski's lab 24/7, they of course have every reason to believe something else has been done to modify the genes of the E. coli to enable them to process citrate.

[edit] See also

[edit] External links

[edit] Other creationist reaction

[edit] Footnotes

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