Skip to comments.Evolution moves more quickly than scientists thought
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.
We will leave it with you. Thanks.
We will leave it with you. Thanks.
I agree completely with your post #512....you nailed it...
*Heck!* Even LC is more specific ! *Gosh!*
BTW, Newton wasn't a liar, though his mechanics were shown to be incorrect. Even Aristotle was no lier, though spilling a lot of claims which were shown to be false later.
The reason: Up to their best knowledge, they told the truth. That's the difference to your posts
Central Archivist/Junior, for somebody who has been throwing around the label "liar", you certainly exposed yourself as fitting the bill completely. Your disavowal in post #541 is the height of being disingenuous.
You can argue for your belief in evolution. However, to use an image of a dildo on a debate opponent, man.. don't you guys have any pride?? That is so eighth grade. For a bunch of "scientists", your credibility is sinking into the gutter, along with your website.
I felt a little sympathy for your cohort earlier this month, but I'm seeing what Jim Robinson saw, when he started cutting you folks down to size.
Appreciate the little revelation there. It sure cuts into anyone's credibility to be caught red handed like that. Just to let you know that people are out there seeing it.
You have demonstrably put forth a complete and utter falsehood regarding your treatment of me on your forum.
You really are a drama queen.
But the BIG LIE calls God a liar. Sounds like you sign on to the BIG LIE and therefore you are calling God a liar. You can call me a liar all you want but if you say God is a liar you will have to answer to Him, not me.
It's a dildo dipwit. Well, I can see where you might have made the mistake, having never seen the real thing before.
Running Wolf, and you, for that matter, can't tell a dildo from the real thing.
DLR and RW make a good pair. I advise everyone from this point on to regard them as joined at the hip.
Eighth grade placemarker.
Disapproving old hag placemarker.
You shouldn't say such things about yourself, ml.
Eighth grade? That's pretty generous.
Took me five tries to get through that stage. *Chuckles*
You need to tell RW that you consider being associated with him insulting.
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.
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.
|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?
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.
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?
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.
#573, mate, #573.
To keep tabs on them. They're sitting behind the wall they erected, and hurl insults at our effigies, and openly mock faith and cuss out Freepers because they disagree. I didn't want that going on unchallenged. But the hyenas couldn't take having a dissenter in the ranks, and so they nuked my account for unspecified, unjustified reasons.
I can't seem to locate a recent post of mine where I detailed the offenses of DarwinCentral. Perhaps J-Ro removed it. Either way, it's a laundry list of the insults they're over there lobbing at us.
Gosh, I've never actually been to that site. I actually thought that Darwin Central, or whatever it is called was a sort of cult group found on college campuses or something.
I'm watching George Carlin talk about "entropy" as I post this.
If that site is reduced to posting such images as what is alleged above, then I'd say that it is not likely to be later counted as among the "fittest" scientific opinion sites as its survival is unlikely. I mean seriously, who could take it seriously?
Entropy makes a lot more sense to me than does Darwinism, which is antithetic anyhow to that notion.
It is not a penus, its a dildo.
Oh, OK, now they make sense.
I get it.
They are "science" oriented because they reject "Authority."
They do not see themselves as the reincarnation of Pope Innocent III.
Conspired to undermine the rule of kings, and later when the rejection of authority tidal wave hit or flooded the church, "that was different."
Someday I'll write a book.
That Pope incited the formulation of the Magna Carta....
"The great charter of freedom."
I see things my way....
The Neodarwinists want to be "the Authority" and that makes them no better than the folks who suppressed Science for generations and centuries, and even millenia....
They use the Courts to help them enforce their BS doctrines.
Just happened to be reading this thread and caught your exchange. The little trick they played with the avatar, is not even highschool level. It's gradeshool.
ROTFLOL!! I've read the exchanges over there and he was constantly taunted and ridiculed. As for the image, if that's your idea of treating someone *quite well*, well, the gutter level that you've been accused of reaching is way too high.
As for the fact that there are other creationists who post there and they aren't banned yet, I suppose that's *evidence* of how open minded and tolerant you are. If you want to back up that claim, you HAVE to allow some of the other side on. It's nothing to brag on.
We've heard from only three evos. Not such a good track record...
The tally so far is:
condemn - 0
condone - 3
How do we know that they've seen this interchange?
Because what one knows they all know. They run together in a pack, like a bunch of lemmings.
Since there's nothing stopping them from posting here, the only reason I can think of for them not to speak out against it, is because they approve of it.
You were treated quite well over there, it was your personality and immaturity that finally got you banned.Was that before or after I was called a punk, full of luddite nonsense, insulated, smart a**, cretard, a lightweight, or when I was told to "shut the f*** up and get the f*** out" etc?
BTW, a Penis, is not a Dildo. I know that you have probably not seen either one of those things RW, but that is your problem not mine.Wolf was the one that said that, but he said it was an image and Junior acted completely indignant, as if they would NEVER stoop to such depths. And then turns around and says it wasn't the real thing, it was an image of one. Well hey, isn't that what Wolf said?
Oh look! Another DC troll. Why don't you go home newb? You've been insulting FReepers since you joined 90 days ago.
Sure they did!
Yup: sure PROVES Evolution, all right!!!
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