Just look at the name of the show, and tell me it's not relevant to crevo threads!
Cheers!
Full Disclosure: Candice Olson is cute, too.
Posted on 05/18/2006 11:16:00 AM PDT by PatrickHenry
Forcing Darwin's hand: capturing natural selection in a flask
Even with modern genomic tools, it's a daunting task to find a smoking gun for Darwinian evolution. The problem lies in being able to say not just when and how a specific gene mutated but also how that one genetic change translated into real-world dominance of one population over another.
Rice University biologists, using an ingenious experiment that forced bacteria to compete in a head-to-head contest for evolutionary dominance, today offer the first glimpse of how individual genetic-level adaptations play out as Darwinian natural selection in large populations. The results appear in the May 19 issue of Molecular Cell.
"One of our most surprising findings is that an estimated 20 million point mutations gave rise to just six populations that were capable of vying for dominance," said lead researcher Yousif Shamoo, associate professor of biochemistry and cell biology. "This suggests that very few molecular pathways are available for a specific molecular response, and it points to the intriguing possibility of developing a system to predict the specific mutations that pathogens will use in order to become resistant to antibiotics."
Rice's study involved the heat-loving bacteria G. stearothermophilus, which thrives at up to 73 degrees Celsius (163 F). Shamoo and graduate students Rafael Couñago and undergraduate Stephen Chen used a mutant strain of the microbe that was unable to make a key protein that the bacteria needed to regulate its metabolism at high temperatures. They grew the bacteria for one month in fermentor, raising the temperature a half degree Celsius each day.
Over a span of 1,500 generations, the percentage of mutant strains inside the fermentor ebbed and flowed as the single-celled microbes competed for dominance. Eventually, one strain squeezed out almost all the competition by virtue of its ability to most efficiently metabolize food at high temperature.
The metabolic protein required to thrive at high-temperature could only be made in one genetic region of the bacteria's DNA, meaning the researchers had only to characterize that small region of the genome for each new strain in order to measure evolutionary progress.
The researchers sampled the fermentor for new strains every other day. Though millions of mutations in the target gene are believed to have occurred, only about 700 of those were capable of creating a new variant of the target gene. In all, the researchers identified 343 unique strains, each of which contained one of just six variants of the critical gene.
The first of the six, dubbed Q199R, arose almost immediately, and was the dominant strain through the 500 th generation. Around 62 degrees Celsius, the Q199R was unable to further cope with the rising temperature, and a new round of mutations occurred. Five new varieties - themselves mutant forms of Q199R - vied for final domination of the fermentor. Three of the five were driven to extinction within a couple of days, and the final two fought it out over the remaining three weeks of the test.
The research included a raft of additional experiments as well. The team characterized each of the mutant proteins to document precisely how it aided in metabolic regulation. The fermentor experiment was repeated and the same mutations - and no others - were observed to develop again. Three of the six genes - the "winner," it's closest competitor and Q199R - were spliced back into the original form of the bacteria and studied, to rule out the possibility that mutations in other genes were responsible for the competitive advantage.
Shamoo said it's significant that the mutations didn't arise where expected within the gene. Four of the six occurred in regions of the gene that are identical in both heat-resistant and non-heat-resistant forms of G. stearothermophilus . Shamoo said this strongly shows the dynamic nature of evolution at the molecular and atomic level.
Shamoo said the most promising finding is the fact that the follow-up test produced precisely the same mutant genes.
"The duplicate study suggests that the pathways of molecular adaptation are reproducible and not highly variable under identical conditions," Shamoo said.
The research was funded by the National Science Foundation, the Welch Foundation and the Keck Center for Computational and Structural Biology.
You can't believe science or physics as a complete source or reliable source. No disrespect intended, but we as humans, includes scientist..:) has only a four dimensional capability. Meaning, that humans understand only length, width, height, and time as reference to their world. They only use 10% of their brains......how can we rely on science when it changes every day.
there is more to the world than just what these humans can design. More than they can imagine.........
There's no reason why ten or a hundred selective pressures shouldn't operate entirely indepedently on the same population.
But, I agree, the experiment could be done. I would bet dollars to donuts unless you choose two pressures that are specifically designed to interfere, they will act independently.
'Tis where the rubber meets the road--did the scientists know, or have a pretty good estimate, in advance --
where the point mutations would have to be in order to increase survival within an increasing temperature environment?
If not, then I think it would be hard to know in advance which pressures would interfere, or not.
E.g. on a much earlier crevo thread I thought I read of the fact there were six mutations which all had to occur in rapid succession in order to generate a flagellum. Even with complete knowledge of the an organism's chromosome, it still looks like a tall order computationally in order to predict *in advance* the possibility of that occurrence.
Which would make the rigorous design of an experiment to predict and effect specific mutations harder to do.
(But that *would* be where the fun would be...as well as driving PETA completely Bat-sh*t.)
Cheers!
Just look at the name of the show, and tell me it's not relevant to crevo threads!
Cheers!
Full Disclosure: Candice Olson is cute, too.
Seriously doubt it. Genomics is cheap and easy. Protein folding and protein chemistry are more difficult.
If not, then I think it would be hard to know in advance which pressures would interfere, or not.
Yes, but why would you adopt the default hypothesis that they interfere? Remember, it's a mathematical truism that any physically realistic function of two variables will in the limit of a small perturbation reduce to linear, independent functions of the variables. To counter that, you have to assume a relatively huge coupling term.
With all due respect here, you're playing the creationist game - that if you can come up with an alternative, no matter how implausible, then we know nothing. It's not science, it's lawyering. In science, we assume the simplest hypothesis first. The simplest hypothesis is that the two pressures are independent. Unless there is evidence they aren't independent, or some reason to expect they aren't independent, there's no reason to assume coupling between the two pressures will affect the rate of evolution.
I wasn't going to stalk you. The reason I emphasized it was because the only post I remember from you was a request for homework help on the religious beliefs of Founding Fathers. Actually, it was one of the first results on Google: http://209.157.64.201/focus/f-news/1505879/posts After it was pointed out to you that your letter was an UL, you never visited that thread again.
You'll be getting reminders from me if you pull that on me, that's all.
placemarker
EXACTLY. You might be able to tell in advance which codon mistranscriptions are most likely. Going from there to say what the 3D structure of the resultant mutant protein is harder; accurately predicting in advance the change in the function of the protein, and its interaction with the other proteins, enzymes, and celluar biochemical cycles is harder yet. And precisely *BECAUSE* the end effect is so hard to gauge from the initial point mutation, I predict it is very hard to design an experiment where you systematically vary two environmental variables, in such a way that you are sure in advance that the adaptations won't step on each other.
IN OTHER WORDS: Yes, I *AGREE* that most of the time, you can approximate the treatment of a situation by mathematical separation of variables. But it does remain an approximation--and there remain times where the approximation may get you into trouble. I just happen to think that the exceptions are going to be very interesting, so I'd like to keep an eye out for them. With all due respect here, you're playing the creationist game
With all due respect here, I'm *not* playing the creationist game...
My point is that this experiment is *FINALLY* getting to the point of *specificity*, and I've been waiting with bated breath for so long for this to happen I can hardly hold in my excitement.
It is not *you know nothing*, it is (in the words of Michael Ledeen from National Review Online, concerning the Middle East) "Faster, please."
Unless there is evidence they aren't independent, or some reason to expect they aren't independent, there's no reason to assume coupling between the two pressures will affect the rate of evolution.
I have acknowledged and comprehended your assertion. I don't necessarily agree that this assertion is *NECESSARILY* true "in vivo" where there are so damn MANY environmental factors to deal with at once. Think of your design tradeoffs within (say) automobile engine design. Gas mileage or power? Torque at low RPM, high top end, environmentally friendly? There is no set answer, it depends on the environment, and changes within the environment. Or (since cars *are* intelligently designed, except for certain GM products ;-) it depends on the market and what features people expect at a particular price point.
Cheers!
How would "creationism" be Latinized?
The best I could come up with was "Res Paleiana", referring to William Paley (published "Natural Theology" in 1800)
In crossing a heath, suppose I pitched my foot against a stone and were asked how the stone came to be there, I might possibly answer that for anything I knew to the contrary it had lain there forever; nor would it, perhaps, be very easy to show the absurdity of this answer. But suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place, I should hardly think of the answer which I had before given....
Same question for "evolution"
How about "Res Darwiniana"? Thanks
<< some Christians use unpopularity as a measure of the correctness of their theology >>
<< Some Christians on this site must be very, very correct indeed. >>
It's part of the game they play in their minds to never question the "rightness" of whatever cause they have embraced as the "Christian crusade" du jour. I have seen it in scores of discussion sites concerning religious topics -- and just about all the crevo discussions online.
Here's how it works:
1) Popularity and success of our "ministry" or "cause" is proof that our cause is right, that God is supporting it, that God is pleased with it, and that God is blessing our faithfulness. Doesn't seem to phase them to realize that causes they oppose and consider virtually Satanic are even more popular and successful.
2) UNpopularity and lack of success is proof that we are in the right, but that the enemy -- SATAN and his dupes -- are fighting tooth and nail to cause us problems. They use this argument even when the opponents causing such "damage" are their fellow Christians who believe their "cause" is dangerous and unbiblical.
The best thing about these two claims is that you will see people using them BOTH in the same argument! I call it their heads-I-win-tails-you-lose game.
Of course, logically -- the popularity or success of such causes is no evidence of their correctness or that God is blessing them because he is pleased with them. That is a logical fallacy known as "argumentum ad populum" -- the argument "to the people," or the argument based on popularity. The answer to this argument is to point out something they oppose that is experiencing great success, popularity, and seeming "blessings from God" -- and ask them if the same argument applies.
Of course -- UNpopularity of an idea is no argument for its rightness OR wrongness. What counts is the actual evidence -- which one side in THIS argument always manages to avoid. Their arsenal seems to consist almost entirely of taking put shots at the evidence from the other side -- evidence they reveal almost total ignorance about.
When we point out this fallacy to them, they then come back with the accusation that we are using the same arguments about popularity of the "cause" when we point out that the overwhelming majority of biologists accept the theory of common descent and consider creationism patent anti-scientific nonsense.
They will throw this accusation at us, while at the same time, trumpeting the polls showing how many Americans "do not believe that we came from monkeys" or some such nonsense. They can't seem to get their minds around the idea that the vast majority opinion of biologists is entirely relevant to this discussion -- while the opinions of millions of people who have no clue about the theory are meaningless -- especially considering that so many of them have GOTTEN their weird ideas about the theory from the straw men dished out by creationists, and from the fact that evolution is so poorly addressed in the schools.
<< How would "creationism" be Latinized? >>
Stercus tauri?
Okay -- to be more serious -- how about:
Res incepti = Things of the beginning [Think "Genesis"].
<< Same question for "evolution"
How about "Res Darwiniana"? Thanks >>
Well -- actually -- I like "evolution." It already comes from the Latin, from a word meaning "to unroll."
There are many verses in the Bible that may imply unpopularity should be taken as a measure of correctness of theology, so it's easy to see where some get that idea, but keep in mind that these verses were written in times where being a Christian was punishable by stoning. If you're a Christian and you're liked by people seeking to stone Christians, there's something wrong with your beliefs. Just like if you're a Republican and you're liked by Democrats, then there's something wrong with your politics. Common sense, and these verses have very little relevance in America, except perhaps on college campuses.
<< There are many verses in the Bible that may imply unpopularity should be taken as a measure of correctness of theology, so it's easy to see where some get that idea, >>
Your further explanation is good -- but there is more at work here. This is very common logical fallacy, beyond the argumentum ad populum I mentioned before.
Let me lay it out logically:
Premise: If our ideas are from God -- God-haters will dispute our ideas and oppose us.
Premise: There are people who dispute our ideas and oppose us.
Conclusions: Those people who oppose us are God-haters, and our ideas are from God.
The conclusions actually reverse the if-then statement:
In logic:
P-->Q (If P is true, then Q is necessarily true).
Q (Q is true).
Therefore, P (P is true).
This is known as "affirming the consequent," and it is a fatal error in logic. P is a sufficient condition for Q, but Q is not a sufficient condition for P.
See it? In this case -- they are saying:
* P->Q = If our ideas are of God ---- then we will be opposed.
* Q = We are opposed.
* Therefore P = our ideas are from God.
This leaves out the possibility that we could be opposed for a lot of other reasons, including the fact that our ideas are NOT from God. Even if it were true that the rightness of one's ideas will cause opposition -- that does not mean that any opposition to one's ideas means that the ideas are right. That is "affirming the consequent."
I hope I have explained this well enough. Apart from the self-delusion involved, it's just flat-out illogical.
Now I await the inevitable response in someone's mind: But God's thinking is far above your man-made reasoning.
Res incepti is good. It's too good, actually, because it looks like a perfectly reasonable field of study. It lacks the often negative connotation that the English suffix "ism" can provide (communism, racism, etc.). Indeed, such negativity is what the creationists themselves attempt when they label evolution as "Darwinism." Because they've set the rules for this controversy (that is, no rules), they can't complain when their own tactics are employed.
I've made a fast search for some rarely-used case or construction that hints at irony, or derision, but I can't find it. I suspect that such exists as an oddball poetic device.
If nothing else is available, I'd just toss the thing into the ablative case, to show how weird it is. Ah, wait! The dative case is used with verbs like credo, confido, etc. That hints (at least to me) of something less than directly comprehended. Thus: rebus inceptis Fortunately, the dative and ablative plural for res are both rebus, so we can't miss. It's the same with 2nd declension nouns like inceptum, therefore inceptis works either way.
[Arrrrrrgghhhhh!!]
<< I've made a fast search for some rarely-used case or construction that hints at irony, or derision, but I can't find it. >>
So -- now we're back to "stercus tauri." LOL!
<< Oh, perfectly clear... you do a good job of smashing peanuts with sledgehammers. :-) >>
Sorry about that. I sometimes get into "teacher" mode, and in my attempt to avoid a protracted back-and-forth, I try to get it all in one post.
<< Wasn't trying to be argumentative, I was adding supplemental background. :-) >>
Yes, I could see that. Nor was I being argumentative. I was just being -- uh -- maybe a little pedantic? I hope not.
Cheers.
<< Magistre
[Arrrrrrgghhhhh!!] >>
Oh, that's a relief! I knew you were addressing me, and I knew you were doing SOMETHING with the word, but I also knew that warn't the usual vocative. I got to thinking -- uh-oh, I've popped off about being a Latin teacher, and this guy knows so much Latin that he's using stuff I never heard of!
I prefer sentina, a word I learned from Cicero. Anyway, using the dative or ablative case (which are conveniently the same for these words), we can subtly distinguish between:
res incepti -- origin studies involving rational conclusions based on objectively verifiable data; andI post; you decide.rebus inceptis -- all other beliefs about origins, from whatever source derived (e.g., authoritarian mandate, communitarian consensus, revelation, or voices from Uranus).
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