3

In the debate between Bill Nye and Ken Ham on Feburary 4, 2014, Ham claimed the Richard Lenski experiments added no new genetic data. He went on to show a clip from Dr. Andrew J. Fabiach, a creationist that teaches at Liberty University,

When I look at the evidence that people cite of E. Coli supposedly evolving over 30 years, over 30,000 generations in the lab, and people say that it is now able to grow on citrate I don't deny that it grows on citrate but it is not any kind of new information. The information is already. It is just a switch that gets turned on and off. That is what they reported and it's nothing new.

Later in the Q/A exchange between Nye and Ham, Ham reiterates this claim,

What Bill Nye needs to do for me is to show me an example of something -- some new function -- that arose that was not previously possible from the genetic information that was there. I would claim and challenge you that there is no such example that you can give. That's I brought up the example in my presentation of Lenski experiments in regards to E. coli; and, there were some that seemed to develop the ability to exist on citrate but as Dr. Fabiach (sp?) has said from looking at his research he has found that that information was already there. It was just a gene that switched on and off. There is no example because information that's there in the genetic information of different animals and plants and so on there is no new function that can be added. Certainly great variation within a kind, but you'd have to show an example of brand new function that never previously was possible. There is no such example that you can give anywhere in the world.

So did the E. coli long-term evolution experiment result in new genetic data from mutation, or not?

  • Why did you remove the tag young-earth-creationism when it's clearly an argument by one to espouse his world view: @articuno. – Evan Carroll Feb 6 '14 at 1:44
  • 2
    @EvanCarroll The question, though, is not at all about young-Earth-creationism. To use the tag in the way you suggest would be a meta-tag, which is discouraged. – user5582 Feb 6 '14 at 2:09
  • Isn't liberty university essentially a creationist/neocon diploma mill originally created by Jerry Falwell? – Shadur Feb 6 '14 at 11:12
  • @Shadur A simple Google search seems to suggest that Liberty University is a private, Christian university. Yes, it's created by Jerry Falwell. It's actually an accredited university and one of the largest evangelical Christian universities in the USA. So, no, it's not a creationist/neocon diploma mill. It may just have students, faculty, and staff who have wacky creationist/neocon beliefs, though. – Double U Feb 7 '14 at 2:03
6

I'll avoid trying to define what "additional genetic information" means and focus on what the Lenski experiment actually shows. The claim from Ken Ham that an existing gene was switched on is essentially correct, although there is a bit more to the whole thing.

The genetic background for the evolution of the Cit+ trait is examined in Detail in the paper "Genomic Analysis of a Key Innovation in an Experimental E. coli Population" from Lensky. They state:

The Cit1 trait originated in one clade by a tandem duplication that captured an aerobically expressed promoter for the expression of a previously silent citrate transporter.

The E. coli strain in this experiment is unable to use citrate as a carbon source under aerobic conditions, a major reason for that is that it can't transport citrate though the membrane. This E. coli strain has a copy of the citT gene which can function as a citrate/succinate antiporter, but this gene is under the control of a promoter that is not active under aerobic conditions.

What the bacteria did that evolved the ability to use citrate under aerobic conditions is that they duplicated the citT gene. The duplicated gene was inserted in a way that put it under the control of an entirely different promoter, which is active under aerobic conditions.

But this is not the whole story, they write in this paper:

The evolution of the Cit1 trait involved three successive processes: potentiation, actualization and refinement.

The process I described is the actualization step. But before this some unspecified mutations were necessary to make this step possible. They didn't identify exactly which mutations those were, but they could show that they must have existed. The third step, refinement was also necessary as the initial phenotype was very weak, and several other mutations substantially increased the ability to use citrate.

  • Well, if the citT gene was originally there, what is all the excitement over? I'm kind of confused. It sounds like Ham was right in his critique. – Evan Carroll Feb 6 '14 at 21:44
  • @EvanCarroll It is still a very interesting experiment, but it is not the one argument to end the creationism issue forever. – Mad Scientist Feb 6 '14 at 21:46
  • @EvanCarroll The excitement was over learning something new about the universe. Ham is only 'right' in his critique if you consider his argumentation style "If you can't explain it in words I can understand despite having zero actual experience in the field, I'm going to call your argument invalid and claim victory". This is not, however, how logic is commonly accepted to work. – Shadur Feb 7 '14 at 9:34
  • Did someone delete my comment? Why? – Evan Carroll Feb 7 '14 at 9:45
  • @Shadur not sure what you're responding too, apparently the admins have taken my comment out which leaves yours without context. – Evan Carroll Feb 7 '14 at 9:46

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .