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Evolution moves more quickly than scientists thought
The Kansas City Star ^ | November 18, 2006 | Eric Hand

Posted on 11/19/2006 1:00:27 PM PST by DaveLoneRanger

ST. LOUIS - Evolution happens. But it can also stop and turn on a dime.

A new study of lizards in the Bahamas shows that the natural selection pressures that drive evolution can flip-flop faster than previously thought - even in months.

"Darwin was right about so many things," said Jonathan Losos, a former Washington University biologist who led the study. "In this case he was wrong. He thought that evolution must occur slowly and gradually."

The lizards and their changing leg lengths are yet another case of evolution occurring in real time. From finches that evolve longer beaks in a few years to bacteria that adapt to strange feeding regimens in days, evolution, as a science, has leapt out of musty museums and into the field.

Scientists say that, from a political perspective, the cases offer a vivid reminder of the continuous process that some people imagine proceeding only in fossilized fits and starts: First monkey, then man.

But for the scientists themselves, the cases show that evolutionary biology has, well, evolved into a predictive, experimental science like any other.

Losos had the perfect Petri dishes: 12 tiny islands in the Bahamas with small populations of insect-eating Anolis sagrei, six-inch long lizards that normally live on the ground but can adapt to life in trees.

On six of the islands, Losos introduced a predator, a large curly-tailed lizard that can gobble up the lizards. He theorized that at first, the fastest prey would survive as they ran for the trees. Natural selection would reward long legs. Then, as the little lizards adapted to life in trees, nimble twig maneuvers and shorter legs would be rewarded.

At the start of the experiment, the scientists, using dental floss nooses on the ends of 10-foot poles, caught all lizards and carefully measured their hind-limbs. After the first six months, their predictions held up. The average leg length of survivors was 2 percent longer than those that were killed. After a year, leg length was 3 percent shorter. The changes were small in absolute terms but statistically very large, said R. Brian Langerhans, a graduate student with Losos.

The study appeared Friday in the journal Science. Losos did the research while at Washington University, but left for Harvard University in June.

The lizard study echoes one of the classic cases of evolution-in-action: Darwin's finches on the Galapagos Islands. For more than 30 years, Princeton University biologists Peter and Rosemary Grant have measured changes in the finches' beaks. After extended droughts, small seeds became more scarce. In a few years, the finches evolved longer beaks to crack the larger, tough seeds that remained. Then as more plentiful times returned, the bird beaks got smaller again.

At Michigan State University, Richard Lenski is studying evolution in test tubes. For almost 20 years, he has reared 12 colonies of E. coli. They have divided more than 30,000 times - which, in terms of human generations, is longer than Homo sapiens has been around. Lenski has challenged the bacteria with strange feeding patterns - feeding them sugars, then starving them.

The colonies all adapted, quickly. But they used different genetic tricks to get there. Their DNA is now remarkably different: an example of parallel evolution.

It's difficult to know how an organism will adapt, and also how subtle environmental changes will kick evolution off in a striking new direction, said Ken Petron, a University of Cincinnati ecologist who worked with the Grants on their finches.

For example, on one trip to the Galapagos during a time of seed scarcity, the Grants expected to find the trend toward larger beaks. But a new, larger finch had colonized the island and was eating the larger seeds, Petron said. It was no longer an advantage for the smaller finches to grow larger beaks.

"It's very difficult to predict the outcome of evolution before it happens," he said.

But if biologists can get better at predicting evolution, it could have applications for areas in which humans are altering the environment and causing evolutionary pressures themselves, Langerhans said. Stanford University ecologist Stephen Palumbi has estimated a $50 billion "evolution bill" associated with the antibiotic and pesticide resistance that bacteria, weeds and insects have evolved in medicine and agriculture.

Had the experiment continued, Losos expected the lizard legs to get even shorter with successive generations. But two hurricanes in quick succession submerged the little islands. "All the living lizards were washed away. Bummer," Losos said.

Some eggs survived, however, and hatchling populations are growing. Losos plans to start the experiment over.


TOPICS:
KEYWORDS: crevolist; evolution; naturalselection; religionisobsolete
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To: DaveLoneRanger

Running Wolf, and you, for that matter, can't tell a dildo from the real thing.


561 posted on 11/23/2006 5:27:30 PM PST by Junior (Losing faith in humanity one person at a time.)
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To: Junior

DLR and RW make a good pair. I advise everyone from this point on to regard them as joined at the hip.


562 posted on 11/23/2006 5:37:41 PM PST by ml1954 (ID = Case closed....no further inquiry allowed...now move along.)
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To: Moorings

Eighth grade placemarker.


563 posted on 11/23/2006 5:44:43 PM PST by Mamzelle
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Disapproving old hag placemarker.


564 posted on 11/23/2006 5:53:19 PM PST by ml1954 (ID = Case closed....no further inquiry allowed...now move along.)
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To: ml1954

You shouldn't say such things about yourself, ml.


565 posted on 11/23/2006 6:03:18 PM PST by metmom (Welfare was never meant to be a career choice.)
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To: Mamzelle

Eighth grade? That's pretty generous.


566 posted on 11/23/2006 6:04:15 PM PST by metmom (Welfare was never meant to be a career choice.)
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To: ml1954
You think creationism and intelligent design are joined at the hip too. So I'm afraid your credibility is considerably lessened on that front.

In the future, when you attempt to insult someone, it would be good of you to ping them as a courtesy.
567 posted on 11/23/2006 7:55:58 PM PST by DaveLoneRanger ("I am here to fight evil and exchange good-natured barbs." - The Tick)
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To: Mamzelle

Took me five tries to get through that stage. *Chuckles*


568 posted on 11/23/2006 7:57:46 PM PST by DaveLoneRanger ("I am here to fight evil and exchange good-natured barbs." - The Tick)
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To: Junior; RunningWolf
Oh YES, Wolf, for GOODNESS' SAKE. It wasn't the image of genitalia, it was the image of a FAKE one. Honestly! Of all the hurtful errors to make.

And you are correct. I proudly admit and proclaim, I have never seen a dildo before.
569 posted on 11/23/2006 8:00:06 PM PST by DaveLoneRanger ("I am here to fight evil and exchange good-natured barbs." - The Tick)
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To: Junior
I was trying to be gentle with you, I see that is impossible, much as reasoning with a dumb ox would be impossible. Here is your sex education.

dildo - Pronunciation Key - Show Spelled Pronunciation[dil-doh]

–noun, plural -dos. Slang. an artificial erect penis, used as a sexual aid.

Man, you and that website are nothing but juvenile punks, and that is probably an insult to juvenile punks as a whole
570 posted on 11/23/2006 8:14:04 PM PST by RunningWolf (2-1 Cav 1975)
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To: DaveLoneRanger

Dildo Central?


571 posted on 11/23/2006 8:18:09 PM PST by Mamzelle
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To: DaveLoneRanger

You need to tell RW that you consider being associated with him insulting.


572 posted on 11/23/2006 8:22:36 PM PST by ml1954 (ID = Case closed....no further inquiry allowed...now move along.)
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To: ml1954

I figured you'd respond that way. But I responded based on your motivation, not how I received it. If I responded based on how I received everything, all you'd see is a bunch of laughing heads.


573 posted on 11/23/2006 8:37:15 PM PST by DaveLoneRanger ("I am here to fight evil and exchange good-natured barbs." - The Tick)
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To: Mamzelle

I am SO resisting using that moniker for them. Mostly because it would come across as vulgar to those who don't know the back story.


574 posted on 11/23/2006 8:38:03 PM PST by DaveLoneRanger ("I am here to fight evil and exchange good-natured barbs." - The Tick)
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To: Junior; DaveLoneRanger; RunningWolf
image
1. a physical likeness or representation of a person, animal, or thing, photographed, painted, sculptured, or otherwise made visible.

But why even bother about that site? It's like being called the boogeyman by the neighborhood bully. So what?

575 posted on 11/23/2006 8:47:40 PM PST by AndrewC (Duckpond, LLD, JSD (all honorary))
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To: DaveLoneRanger; RunningWolf; Mamzelle
I wonder where the chorus of condemnations for that kind of behavior and that kind of lying is?

All I hear is ***crickets chirping***

Must be since none of the evos are condemning it they are giving it their whole-hearted approval. It says a lot about the group as a whole.

576 posted on 11/23/2006 8:49:49 PM PST by metmom (Welfare was never meant to be a career choice.)
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To: DaveLoneRanger

I don't blame you for not wanting to be associated with RW. But you really should tell him that. Don't you think that would be the right thing to do?


577 posted on 11/23/2006 8:49:58 PM PST by ml1954 (ID = Case closed....no further inquiry allowed...now move along.)
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To: Junior; DaveLoneRanger
Good try to get away from the fact that you and your web site behave that way, thats how you treat your guests.

It is unreal & bizarre, there is no explanation for it.

W.
578 posted on 11/23/2006 9:14:00 PM PST by RunningWolf (2-1 Cav 1975)
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To: ml1954; DaveLoneRanger
Look I don't care if DaveLoneRanger wants to be associated with me or not. I don't need him and he does not need me, we stand on our own.

But if nothing else you evos are very effective at relentlessly attempting to steer the discussion to an area that favors you, in this case away from just how sleazy and pathetic the evo ping list members = dildo-central really is.

But it aint working.

W.
579 posted on 11/23/2006 9:18:49 PM PST by RunningWolf (2-1 Cav 1975)
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To: metmom

Aren't the crickets lovely this time of year? I think they chirp to stay warm, which just adds that little touch of gusto brought on by half-frozen insects.

I tend not to assume just because the evos don't condemn it is a reason to assume they support it. For example, how do we know that they've seen this interchange? I'd love to ask them, but they won't let me on their forum, and they're staying off this one like vampires avoid garlic.


580 posted on 11/23/2006 9:32:57 PM PST by DaveLoneRanger ("I am here to fight evil and exchange good-natured barbs." - The Tick)
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