major evolutionary change seen in the lab

[_Sethbag]

One of the major claims of Intelligent Design theory is that there are aspects of life that are complex enough that they couldn't have evolved, because evolution would require a lot of small steps, and the particular feature in question is supposed not to work with some of the steps removed. With only some of the small steps in place, the evolutionary advantage is said not to support the survival of those small steps, so the big complex change can never happen.

A scientist took a single e. Coli bacterium and derived 12 populations from its offspring, and has tracked them for years now. He also took samples of the populations every 500 generations and froze them so he can go back, revive them, and "replay" them at will to see if the same things will be observed to happen.

He observed a major change in the bacteria, with one of the 12 populations developing the ability to metabolize citrate, which is an ability that e. Coli has not had before.

He went back and re-grew various samples taken from the history of these 12 populations, and discovered that he could only get this ability to redevelop if he started with ancestors from the same population, from the 12, that had first developed it, and only if he started with bacteria from after a certain generation, some 10,000 generations before the citrate-metabolizing trait first arose.

The research seems to be demonstrating that a collection of various subtle changes eventually lead to the development of this major new ability, and that without these pre-requisite changes, the major new ability simple doesn't happen later on.

It's interesting stuff, because it pokes a finger straight into the eye of ID claims. It actually shows, in a lab, a kind of evolutionary change that ID theorists have claimed wouldn't happen.

Here's the article.

[_Thama]

The obvious ID response to this will be that the ability to metabolize a chemical isn't a major development, and is not comparable to the formation of an organ or limb.

Those familiar with biochemistry and genetics realize that the opposite is true: a new metabolic pathway is more difficult to produce through selection mechanisms that a wing or an eye. Homeotic mutations allow a simple point mutation to produce structural changes as profound as addition of limbs, wings, or body segments within the course of a single generation in some animals, and the incremental processes by which the eye may have evolved (with increasing selective advantage at every step) have been well established. However, the coagulation cascade was a much more formidable opponent for those attempting to falsify the ID claims of irreducible complexity on that issue, and the fitting of an enzyme to a new substrate at multiple steps is also challenging (though not insurmountable) for the evolutionary model.

This is huge.

[_EAllusion]

I posted this here:

http://www.rottentomatoes.com/vine/show ... p?t=630354

Voivod is good people. He posted a few notable examples of observing evolution in action.

I think this is more on the order of neat than mindblowing, but let's have fun predicting the ID responses based on their history.

1) This was incredibly unlikely, and it was just a tiny change. Now imagine how unlikely that makes bacterium turning into humans is. It's one in an impossible to concieve number.

2) This experiment was run by scientists defining the parameters, therefore it is actually an instance showing how intelligent design is needed to drive speciation.

3) No new information was added. If you look, you'll find that mutations merely destroyed what already was there.

4) All this shows is microevolution occurs, which we all know, but doesn't prove the fairytale atheist dogma of macroevolution.

[_Runtu]

How do we know that God didn't cause the mutation? :)

[_The Nehor]

Well, the conclusion we must draw is obvious. SATAN is messing with cell cultures to deceive us. We should burn all the research and test all the researchers for possession and test them as witches. I volunteer to try the exorcisms.

Seriously though, this is neat. I couldn't find any other reports on this and want to read more. Anyone see any?

[_The Dude]

This is huge.

No, it's micro. Microorganisms. Microevolution. You get the picture. lol

I see creationists saying "See! I told you evolution was all about random chance. Those scientists didn't design the system and the organisms didn't seek out citrate, it all just fell into place by pure chance. What are the odds of that happening? Oh wait... it did happen. Doh! But that doesn't mean humans came about by chance. Nu-uh! No way! Evolution is a lie, I tell 'ya. Says so in the Bible." Of course, for creationists it is all about the odds of a predetermined combination falling into place. Evolution, meanwhile, does not actually proceed with the cart before the horse.

[_Bond...James Bond]

How long does a "generation" last at that level?

[_The Nehor]

How long does a "generation" last at that level?

It's been going since 1988 and they've had over 44,000 generations. That means 44,000 generations in 7,300 days so probably a little over 6 a day or about one every 4 hours.

[_The Dude]

I posted this here:

http://www.rottentomatoes.com/vine/show ... p?t=630354

Ha! Now I've discovered what "E" means in "EAllusion". You have a ton of posts over there.

This is cool, but it will be very interesting once they document the step-by-step DNA changes that brought about the ability to eat citrate.... Personally, if I were a reviewer, I would have asked for that information. Importantly, PNAS (the journal that published this) doesn't require peer-review for all submissions by academy members. Oops! That's what the creationists are really going to complain about:

Contributed by Richard E. Lenski, April 9, 2008 (received for review March 26, 2008)

[_Moniker]

2) This experiment was run by scientists defining the parameters, therefore it is actually an instance showing how intelligent design is needed to drive speciation.

I already saw this response posted earlier on another message board.