Lenski results challenge creationism
From RationalWiki
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 a beneficial mutation, 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 descendants of that group, and only the frozen descendants 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),[2] 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.
Contents |
[edit] General problems for creationists
Creationists come in many different flavors, but the process as outlined above will cause problems of one sort or another for many of them.
- Some creationists deny that any form of evolution occurs and this clear demonstration of the process is an obvious challenge to them.[3][4]
- Others will claim that all mutations are inevitably harmful[5] and this beneficial mutation will be hard for them to accept.[6]
- Yet others claim (erroneously) that the second law of thermodynamics would not allow evolution to generate more complex life forms[7] - yet here we see it doing just that. It is creating new information.[8] [9]
- Many creationists hold to a false dichotomy of microevolution and macroevolution[10]. By this they mean that organisms may change, for example, their size or color but that they are unable to develop wholly new traits. (Although they have never been able to say what the limiting factor is.) But again, this experiment shows them developing new traits.[11]. 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.[12]
[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 reaction
Seeing many of their favorite myths so clearly under challenge, it is not surprising the 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 minimise the importance of the results by Young Earth Creationists, to some kind of weird double-think by Believers in Intelligent design.
[edit] Outright Rejection - Conservapedia
As of June 2008 the most appallingly unsuccessful attempt was that made by Andrew Schlafly, the founder of Conservapedia, which resulted in his receiving a remarkable public spanking in the Lenski affair. The history of this vain attempt is recounted elsewhere on this wiki but here we note that Andrew Schlafly seems to have been rather abandoned by his co-religionists in this effort, possible because they feel it is a losing strategy.
[edit] It's not what it looks like - OEC Response
Answers in Genesis claims [13] 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 so "degenerative events" would seem to be unlikely.
[edit] Yes, it's evolution but it's compatible with ID - ID response
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.
[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. [14]
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 occassion modify genes of organisms to bring about certain results), but because Lenski simply provided the environment for several generations that placed the pressure on those bacteria to adapt to absorb citrates: the bacteria evolved through a natural process to adapt to the constraints of their environment, just as the theory of evolution predicted they would.
[edit] See also
[edit] External links
A PDF of the paper from Prof Lenski's site
[edit] Other creationist reaction
- Multiple Mutations Needed for E. Coli (Michael Behe's Amazon Blog)
- On the evolution of a "key innovation" in Escherichia coli (Access Research Network - ID apologetics)
- Uncommondescent 1 and Uncommondescent 2
- "Experimental Support for Historical Contingency Challenges Biological Evolution." Except it doesn't.
- The "science against evolution" page
[edit] Footnotes
- ↑ NS:bacteria make major evolutionary shift in the lab
- ↑ unexpected evolution of new trait
- ↑ ID society Kansas - Evolution does not happen
- ↑ AIG denies macroevolution and microevolution
- ↑ Erroneous creationist claim that all mutations are harmful
- ↑ See for example AiG's response to Lenski's paper
- ↑ second law
- ↑ MSNBC - Lenski's E. coli have new information
- ↑ New Scientist - Bacteria more complex
- ↑ Creationists claim distinction between "microevolution" and "macroevolution"
- ↑ Lenski paper - E. coli develop ability to metabolize citrate
- ↑ E.Coli defined by inability to metabolize citrate
- ↑ AIG response
- ↑ http://freerepublic.com/focus/chat/2052325/posts?page=18#18 Free Republic: "Bacteria Reveal Secret Of Adaptation At Evolution Canyon "

