Uncommon Descent Serving The Intelligent Design Community

Computer Simulations and Darwinism

Categories
Intelligent Design
Share
Facebook
Twitter/X
LinkedIn
Flipboard
Print
Email

Okay dudes, no more talk about my abandonment of atheism. Here’s some science and engineering talk.

I know something about computer simulations. In fact, I know a lot about them, and their limitations.

Search algorithms (and especially AI-related search algorithms) are a specialty of mine, as is combinatorial mathematics.

The branching factor (the average number of moves per side) in chess yields approximately 10^120 possible outcomes, but the number of legally achievable positions is approximately 10^80 — the estimated number of elementary particles (protons and neutrons) in the entire known universe. Compare this to the branching factor of nucleotide sequences in the DNA molecule. Do the math.

Finite element analysis (FEA) of nonlinear, transient, dynamic systems, with the use of the most sophisticated, powerful computer program ever devised for such purposes (LS-DYNA, originally conceived at Lawrence Livermore National Laboratory in the mid-1970s for the development of variable-yield nuclear weapons) is another of my computer-simulation specialties.

Dyna has been used heavily in the automotive industry for simulating car crashes, so that cars can be designed to produce the least damage to occupants.

In these simulations everything is precisely known and empirically quantified (the material properties of the components — modulus of elasticity, mass density, shear modulus, precisely calibrated failure modes, etc.).

In addition, the explicit FEA time step (the minimal integration time step determined by the software based on the speed on sound in the smallest finite element and its mass density, which is required to avoid numerical instability) is critical. In my simulations the time step is approximately a ten-millionth of second, during which partial differential equations, based on the laws of physics (F=ma in particular) are solved to compute the physical distortion of the system and the propagation of the forces throughout the system in question.

One learns very quickly with FEA simulations that even with all of this knowledge and sophistication one must empirically justify the results of the simulation incrementally by comparing the results with the reality it attempts to simulate.

One false assumption about a material property or any of the other aspects of a simulation can completely invalidate it. Worse yet, it can produce results that seem reasonable, but are completely wrong.

So, the next time someone tries to convince you that a computer simulation has validated the creative power of the Darwinian mechanism of random errors filtered by natural selection in biology, you should tell them to go back to school and learn something about legitimate computer simulations, and how difficult it is to produce reliable results, even when the details are well known.

Comments
Elizabeth, you wrote: "In fact, if the ID argument was that only a God could have invented a universe that could bring forth Chopin, I’d be almost fine with it. What I’m not fine with is the idea that the only possible God is one who had to tinker with his/her creation from time to time in order to ensure that Chopin turned up. The theory that the universe actually works without outside interference seems infinitely more marvellous to me than one that requires a maintenance engineer It is also, IMO, one that is supported by overwhelming evidence." 1. "The ID argument" isn't about God at all. It's about inferring design. You may object, saying that many ID proponents identify the designer with the God of their religion. But that identification is not part of ID per se, as ID people have been saying ad nauseam for 15 years now. I'm not going to bother to find you quotations for this. If you are a responsible critic of ID, i.e., if you read what ID proponents say for themselves as opposed to rumors spread about them by their opponents, you will have seen many statements like the one I have just made. 2. To speak about "the only possible God" is to speak theologically. ID is not theology; it is branch of the information sciences, applied to biology (and sometimes also to cosmology). I have not heard leading ID proponents make statements about "the only possible God" in their theoretical writings about design detection. And even in the case of *some* ID proponents, who write about God in popular apologetic works, I haven't heard them speaking of "the only possible God" -- they merely defend their own conception of God. I don't know where you are pulling up this phrase, but it either never or only rarely appears in literature written by ID proponents. 3. It is not an inherent part of ID that the designer has to "tinker" with anything. Some ID proponents may personally believe that the Designer did in fact "tinker" with nature, but tinkering is not part of ID per se. You here fall into the same confusion that most ID critics fall into. You think that ID is about affirming supernatural interventions as against purely natural causes. It isn't. It's about affirming design as against chance. And a design can be implemented through purely natural causes, through a chain of events in which there is no divine intervention. Have you ever played the game "Mousetrap"? Everything that happens once the "boot" kicks the sign is purely natural; there is no intervention by the player. Yet the whole sequence is designed by the game manufacturer. Substitute "first life" or even "Big Bang" for the action of the boot, and you have one possible interpretation of evolution from an ID perspective. In fact, that is exactly the interpretation of evolution you will find in Michael Denton's second book. No miracles. No interventions. And Michael Denton is definitely a design theorist, at least "id" if not "ID". 4. Whether or not something seems more marvellous to someone has nothing to do with its truth. The world of revealed religion seems more marvellous to most people than does the world postulated by atheism, but I don't think you would agree that this is an argument for revealed religion against atheism. 5. Your notion of "overwhelming evidence" is curious. We don't even understand 1% of what happens in the universe, and you are confident that "the universe works without outside interference"? We don't have even one complete hypothetical evolutionary pathway for the origin of any major organ or system, and you are confident that evolution works without outside interference? I guess people trained in philosophy are much more skeptical than those trained in biomedical fields, because I don't have your confidence. For all I know, all events may indeed happen without any "outside interference"; but I certainly do not think the evidence for such a claim is "overwhelming." In fact, I don't think such a claim arises primarily out of "evidence" in the first place. The claim is primarily an operational postulate of modern scientific research, not something that has been proved by modern scientific research. There isn't a single event, no matter how strange or miraculous-seeming, that a modern scientist wouldn't try to find a natural cause for. If Jesus rose from the dead today, the laboratory staff would be all over him, grabbing blood and tissue samples and putting his brain through a scan and so on, trying to isolate the natural cause of his resurrection. Thus, any possible counterevidence to naturalistic assumptions is simply turned into a new question for naturalistic science to answer. Modern science is methodologically blind to supernatural events, even if they do occur. So to speak of "overwhelming evidence" is to misconstrue the nature of modern scientific practice. Modern science could never find evidence that would count against its own inescapable assumptions. T.Timaeus
October 12, 2011
October
10
Oct
12
12
2011
07:03 PM
7
07
03
PM
PDT
You said it takes a brief time. How many times has it been tested, and what have these bacteria evolved into?
They evolved into bacteria adapted to a new food source. Nearly every every living thing in the world is a microbe or virus. By number, by weight, by variety. Why the obsession with evolving into something else? It's not what TOE predicts.Petrushka
October 12, 2011
October
10
Oct
12
12
2011
05:42 PM
5
05
42
PM
PDT
"...10 and 20 was equiprobable and no other number occurred, which seems vanishingly unlikely to me." This is exactly what happened. All beneficial fixed mutations fell within 10 and 20 for all 12 isolated populations. It does appear that no other number occurred. "Although the bacteria in each population are thought to have generated hundreds of millions of mutations over the first 20,000 generations, Lenski has estimated that only 10 to 20 beneficial mutations achieved fixation in each population, with less than 100 total point mutations (including neutral mutations) reaching fixation in each population." Concerning fixed beneficial mutations (10-20), this is not Gaussian distribution. With a 100 total fixed cap. This is flat. I wager the Avida distributions are Gaussian. In fact many of the examples on youtube often cited are normal bell curve. However, the lenski e-coli seems to be flat, indicating a wall. If this is true, than the Avida results are not representative of what is evidenced by the largest evo field study to date. I have never seen the Avida data. But I have a hunch based on other sim results I have seen.junkdnaforlife
October 12, 2011
October
10
Oct
12
12
2011
04:00 PM
4
04
00
PM
PDT
There is a terrible abuse of the word "probable" in the above exchanges! Probability is, essentially, a measure of uncertainty. Once something has happened, all uncertainty is ended. Bearing this in mind, try reading through the above posts :)Elizabeth Liddle
October 12, 2011
October
10
Oct
12
12
2011
02:13 PM
2
02
13
PM
PDT
Petrushka, In response to
Every possible state of the universe is astronomically improbable.
You said
The fallacy is that evolution doesn’t test every possible state in the universe.
You're crossing discussion points. As I said before, I get it. Almost everyone gets it. Evolution tests the surrounding points. You said this before and I believe I acknowledged it.
A population of bacteria, even a small population, can buy every possible lottery ticket.
What is this fixation with lottery tickets? Is there some magic correlation between lottery odds and evolution? Which lottery are you even talking about? Nonetheless, you're making my point very well for me. Lenski is giving those bacteria every opportunity to buy as many lottery tickets as they can, and where exactly has it gotten them?
The Lenski experiment demonstrates that all the one step changes can be sampled by a small population in a very brief time.
Really? So after that very brief time, the modified bacteria were now searching from a new "point," one step from where they were. What happened after the next brief time when they searched the points that were nearest to them in their modified state? What happened the next time, and the next? You said it takes a brief time. How many times has it been tested, and what have these bacteria evolved into? Let me guess: The search spaces available within single-step increments don't get them very far. They are still living the same bacterial lives as their distant ancestors. Why do you keep making the point that you intend to argue against? The only meaningful tests ever conducted indicate that evolution is real, it produces variations, and it appears to have limits.ScottAndrews
October 12, 2011
October
10
Oct
12
12
2011
12:38 PM
12
12
38
PM
PDT
Lastyearon, One more note on this:
can you think of one past event(not related to biology/evolution) that was too improbable to be plausible?
As I have repeatedly pointed out, plausibility is subjective. It is not a measurement of probability, much less possibility. I think you're confusing plausible with possible. Plausible is a film plot or a homework excuse. If someone told you that you were going to get struck by lightning on five different occasions during your lifetime, you would probably say that they were crazy. It's not plausible. It is highly improbable, but it is not impossible. Improbable and impossible will never be the same thing. Getting hit by lightning 1,000 times in a lifetime is improbable. But it's improbable enough that we safely rule it out. Where exactly do you draw that line? Even that is subjective. But can you see the difference between acknowledging that an improbable event might happen, acknowledging that one has happened, and using a series of improbable events that you can't even define as an explanation? Look for a better explanation, or realize that you don't have one and leave it at that.ScottAndrews
October 12, 2011
October
10
Oct
12
12
2011
12:17 PM
12
12
17
PM
PDT
Lastyearon, Are you just throwing stuff to see what sticks?
You contradicted yourself in your last paragraph. First you said that “Every possible state of the universe is astronomically improbable”. And then you said, “within that reality, some events are probable”. How can some events be probable if every state of the universe is astronomically improbable?
When you consider any two events, the general improbability of the state of the universe applies to either of them. You can factor it out. Yes, given the state of the universe five billion years ago, its present state is one of many possible states, and is therefore improbable. Does that mean that when you throw a rock in the air it's not more likely to fall than to fly into space or turn into a whale? How can I make this any simpler? Probability is a rough measurement. It measures which things are more or less probable. What does it say about your point of view if it requires you to first undermine and negate the very concept of probability? Isn't that a giant red flag?ScottAndrews
October 12, 2011
October
10
Oct
12
12
2011
11:55 AM
11
11
55
AM
PDT
Lastyearon, That's a nonsensical question.
can you think of one past event(not related to biology/evolution) that was too improbable to be plausible?
Probability or the lack thereof can apply to past events. Plausibility cannot. A thing either happened or it didn't.ScottAndrews
October 12, 2011
October
10
Oct
12
12
2011
11:20 AM
11
11
20
AM
PDT
Every possible state of the universe is astronomically improbable.
The fallacy is that evolution doesn't test every possible state in the universe. For the most part it tests those states that are one point mutation away from the current state. There are, of course, many minds of genomic changes in addition to point mutations, but these basically shuffle existing sequences without changing them. The Lenski experiment demonstrates that all the one step changes can be sampled by a small population in a very brief time. A population of bacteria, even a small population, can buy every possible lottery ticket.Petrushka
October 12, 2011
October
10
Oct
12
12
2011
10:28 AM
10
10
28
AM
PDT
Scott, You contradicted yourself in your last paragraph. First you said that "Every possible state of the universe is astronomically improbable". And then you said, "within that reality, some events are probable". How can some events be probable if every state of the universe is astronomically improbable?lastyearon
October 12, 2011
October
10
Oct
12
12
2011
10:17 AM
10
10
17
AM
PDT
some [events] are too improbable to be plausible
Scott, can you think of one past event(not related to biology/evolution) that was too improbable to be plausible?lastyearon
October 12, 2011
October
10
Oct
12
12
2011
10:13 AM
10
10
13
AM
PDT
The problem with the Powerball/lightning strike analogy is that that it compares the probability of more probable events to that of less probable events. Measurements of probability exist precisely to distinguish between the two. If 50 million tickets out of 500 million combinations is comparable to 1 in 10^100, then the very concept of probability is meaningless. Every possible state of the universe is astronomically improbable. Let's just put that out there and acknowledge it. Now, do we throw away the concept of probability, or do we accept that within that reality, some events are probable, some are less probable, and some are too improbable to be plausible? It's a valid concept or it's not. You can't acknowledge it and then use meaningless comparisons to negate it when it's inconvenient.ScottAndrews
October 12, 2011
October
10
Oct
12
12
2011
08:36 AM
8
08
36
AM
PDT
would you acknowledge that Behe’s irreducible complexity is a real principle in biology and that some *existing* systems are simply out of reach of Darwinian evolution?
Things are not out of reach because of Behe's principle. Anything that requires a succession of improbable events is out of reach if you are trying to predict the future, but not necessarily so if you are trying to discern the past. We have a communication problem regarding probability. Any specific event can be incredibly unlikely (getting hit by a meteorite, winning Powerball, your parents getting together and conceiving you). And yet things happen, despite the incredible odds against. This is why we can't predict the future in detail. From my perspective, ID makes the mistake of looking at the odds against Joe winning Powerball after he has won. Dembski has actually written a paper on this in which he uses his explanatory filter to decide whether elections were deliberately rigged by placing candidates on a ballot in a certain sequence. There's also an interesting recent case of a woman statistician who has apparently figured out how to win scratch-off card games. The evidence is that she has math skills, and she has won a lot of money over a long period of time. There are uses and misuses of this process. It seems so intuitive, and yet it is subject to all kinds or reasoning errors. When you are trying to figure out whether an election has been rigged or a lottery is not random, you are deciding between likelihoods of competing theories. This is a Bayesian analysis (something Dembski used in the election analysis). You have to know something about the situation and the possible ways in which a particular end could be achieved. In order to rig an election, you have too have physical access to some aspect of the ballot process. In order to "cheat" at scratch-off cards, you have to have access to some aspect of the cards. Apparently in the case of the cards, there were clues in the card serial number. I believe in an older case of Lotto cheating, the winners were related to people who did the drawings. Returning to Behe's principle, the problem is he is astonished that certain sequences of change have occurred, but he offers no particular reason why they shouldn't have. He offers what I consider a rather disingenuous argument that we cannot predict the course of future evolution. I consider this equivalent to asserting we cannot predict the names of the next three Powerball winners. And yet there will be three winners. Behe's principle hinges on what is known as Dollo's Law. Originally it dealt with the irreversibility of a particular evolutionary path. It has been generalized to argue that any particular path is improbable. Having three lotto winners, one cannot expect that a rerun of the drawings would produce the same winners. But one cannot say the winners were specified in advance. And in evolution, one cannot say that the particular size, shape, color or decorative feature of an organism was specified in advance. One thing established by the Lenski experiment is that given a population of bacteria, all possible point mutations will occur. There is no bias toward useful mutations. This is interesting for another reason, and that is that a relatively small population of bacteria, in the course of a couple decades, can explore the entire functional landscape of incremental changes. A third interesting finding is that a change that confers no immediate benefit, and some slight harm, can be preserved in a population, and can eventually become useful when combined with further mutations. This has been a hypothesis for half a century, but has now been observed.Petrushka
October 12, 2011
October
10
Oct
12
12
2011
08:07 AM
8
08
07
AM
PDT
Are you asking me what existing systems couldn't evolve?
So with that clarification and if such a computer program were written, would you acknowledge that Behe’s irreducible complexity is a real principle in biology and that some *existing* systems are simply out of reach of Darwinian evolution?
Let me check I understand your question. You originally asked:
If I were to write a computer program based on the idea that some biological systems are irreducibly complex and that a Darwinian pathway would not be able to achieve them, and after running the program, sure enough, the Darwinian approach did not achieve them, would you be willing to publicly acknowledge that Behe’s irreducible complexity is a real principle in biology and that some systems are simply out of reach of Darwinian evolution? If not, why not?
Are you proposing that your hypothetical Darwinian computer model is of an actual existing biological system? And that if a virtual version of that system couldn't evolve within your evolutionary model, then we would have to conclude it was out of reach of evolution? Well, no. All you would be able to conclude is that, given the parameters of your model, the thing is very unlikely to evolve. That conclusion is only as good as your model. The better (more realistic) your model, the more confident you might be that the thing in question really was unevolvable, but we can never rule out a missing parameter. Indeed, many of the great breakthroughs in science have been in finding missing parameters - finding a key overlooked factor that explains otherwise "unexplainable" phenomena. But there's another problem: in a system as complex and varied as biological systems, the changes of a specific "target" feature evolving is very small, although the chances of a feature that performs some target function may be quite high (this is true of AVIDA, by the way: what is "rewarded" is not a specific algorithm, but one that performs a specific function - many possible algorithms may do this). So if, in your model system, your virtual organisms evolved a motility system involving, say, some kind of jet propulsion principle that doesn't happen to exist in nature, when what you were trying to model was, say, some kind of rotary engine principle (like the bacterial flagellum) - would you conclude that flagella were unevolvable? Or might you rather conclude that motility systems tend to evolve, but that the probability of any one system evolving is quite low (just as the probability of any hand of cards is 1, while the probability of any given hand of cards is vanishingly small)?Elizabeth Liddle
October 12, 2011
October
10
Oct
12
12
2011
07:01 AM
7
07
01
AM
PDT
If, as the theory of evolution proposes, adaptation of populations to their current environment is via incremental changes, each of which may be only slightly beneficial (or, it turns out, neutral or even slightly deleterious), but which accumulate via selection and drift to provide adaptive "solutions" to the current environment, centaurs (hexapods) would have to diverge from the lineage that produced tetrapods long before tetrapods evolved forelimbs that served as arms with hands. Evolutionary processes can only build on what goes immediately before. The one sort-of exception is hybridisation, but that is still only possible up to a certain point after speciation. Even if you crossed a horse with a human, you wouldn't end up with a centaur, because neither parent has genotypic information that specifies six limbs. Now it's possible that in the remote future, hexapods might evolve from our current fish population, and six-legged vertebrates with hoof-like hind limbs and hand-like forelimbs might be one form they take, but the probability that the hind-limbs might bear more than a passing resemblance to a horse, and the forelimbs more than a passing resemblance to a human, that it should have mammal-like hair and sets of mammary glands between each pair of limbs, mammalian jaws and ear bones, and language function is simply vanishingly unlikely. Convergent evolution does occur, but only extremely rarely does the same body-part evolve similar functions in both cases, and the probability that many would do so, in a completely different lineage, is obviously infinitessimal. Never mind a rabbit in the pre-cambrian, a centaur (a breeding population of centaurs, anyway), anywhere, would simply not fit into any Darwinian phylogeny.Elizabeth Liddle
October 12, 2011
October
10
Oct
12
12
2011
06:45 AM
6
06
45
AM
PDT
It was reached via neutral and even slightly deleterious pathways.Elizabeth Liddle
October 12, 2011
October
10
Oct
12
12
2011
06:10 AM
6
06
10
AM
PDT
Well, from where I am sitting, it is you who are confused. Certainly the starting population was designed, as was the fitness landscape. What was not designed were the evolving virtual organisms themselves. Each mutation was completely blind; the vast majority were neutral or deleterious; Moroever, the "rewarded" i.e. beneficial mutations were both rare and separated by necessary but non-beneficial step; therefore there was no direction. Therefore the evolution of each function was both blind and undirected, thus simulating biological evolution. You appear to have made a mistake.Elizabeth Liddle
October 12, 2011
October
10
Oct
12
12
2011
06:08 AM
6
06
08
AM
PDT
Evaluation of neo-Darwinian Theory using the Avida Platform. Part 1. Evaluation of neo-Darwinian Theory using the Avida Platform. Part 2.Joseph
October 12, 2011
October
10
Oct
12
12
2011
05:24 AM
5
05
24
AM
PDT
As for EQU- what is the evidence that EQU can arise via blind, undirected physical processes?Joseph
October 12, 2011
October
10
Oct
12
12
2011
05:23 AM
5
05
23
AM
PDT
Perhaps you can show how self-reproduction arose via blind, undirected physical processes.Joseph
October 12, 2011
October
10
Oct
12
12
2011
04:47 AM
4
04
47
AM
PDT
But anyway you still have issues with the fact that ID is not anti-evolution and things that are designed to evolve. evolve by design are in no way connected to darwinism.
I look forward to the day when you flesh out that statement.
Genetic algorithms already "fleshed it out", duh.
It makes no sense to me.
Typical. Ya see organisms could be evolving by design- as in they were designed to evolve, meaning that evolution is directed as opposed to blind and undirected.Joseph
October 12, 2011
October
10
Oct
12
12
2011
04:43 AM
4
04
43
AM
PDT
Ummm Behe argues only against blind and undirected processes producing IC. And AVIDA does not simulate that. Game over...Joseph
October 12, 2011
October
10
Oct
12
12
2011
04:40 AM
4
04
40
AM
PDT
Elizabeth:
Yes, I know it is, Joseph. But, it turns out Behe is wrong. And so are you. AVIDA demonstrates that even blind and undirected process can result in the evolution of IC functions.
No, it does not do that. You are confused. AVIDA does not simulate biological evolution, you lose. With AVIDA EVERYTHING was DESIGNED- the starting organism, the resources, the reward- it does NOT reflect/ simulate blind and undirected physical processes.Joseph
October 12, 2011
October
10
Oct
12
12
2011
04:39 AM
4
04
39
AM
PDT
What was IC about Thorton's example?Joseph
October 12, 2011
October
10
Oct
12
12
2011
04:35 AM
4
04
35
AM
PDT
Please could you provide the actual citation. What you are saying is profoundly unclear. For a start, "exactly 15 +-5" is not the nomenclature for a flat distribution, unless you are saying that every number between 10 and 20 was equiprobable and no other number occurred, which seems vanishingly unlikely to me. And even if it was, I'm not seeing your point. Could you be specific?Elizabeth Liddle
October 12, 2011
October
10
Oct
12
12
2011
04:16 AM
4
04
16
AM
PDT
If intermediate steps are deleterious but nonetheless in the long run they lead to benefit in terms of survival, they are not deleterious.
Your are playing word games. There are several ways in which deleterious changes can become fixed in a population. In humans sickle cell trait is recessive and is beneficial unless it is homozygous. Another way is for the change to occur in a duplicate gene, in which case it may have little or no effect. Another way is for it to occur after a compensating change. Another way is for it to be nearly neutral. Another way is for it to deleterious in its original environment, but beneficial in its current environment. Another way is for it to hitchhike on a beneficial mutation. You may wish to ignore all this, but the compensation scenario has has in fact been tested in pathetic detail by Thornton.Petrushka
October 10, 2011
October
10
Oct
10
10
2011
12:44 PM
12
12
44
PM
PDT
Let us step back a bit and think. If intermediate steps are deleterious but nonetheless in the long run they lead to benefit in terms of survival, they are not deleterious. Consequently, everything is beneficial, and therefore we haven't explained anything. In this case, is impossible to substantiate extinction or non-existence of fairy tale creatures. My point is that it is possible to "prove" anything with this kind of logic. Generally speaking, I believe that a system of statements allowing anything to happen (positive, neutral and deleterious) is trivial and delivers zero information. In which case the notions of positive, neutral and deleterious lose their distinctive meanings.Eugene S
October 10, 2011
October
10
Oct
10
10
2011
12:28 PM
12
12
28
PM
PDT
BTW, you didn't respond to the point of my question. I'm not talking about fairy tale creatures we know don't exist. It's easy to admit Darwinian evolution can't account for them because they don't exist; thus your theory is rhetorically protected. How convenient. Of course I'm talking about real biology, so I apologize if you misunderstood my question to think I was talking about fairy tale creatures that don't exist. Just put the word "existing" in front of "systems." So with that clarification and if such a computer program were written, would you acknowledge that Behe’s irreducible complexity is a real principle in biology and that some *existing* systems are simply out of reach of Darwinian evolution? If not, why not?Eric Anderson
October 10, 2011
October
10
Oct
10
10
2011
10:47 AM
10
10
47
AM
PDT
What principle of evolution dictates that centaurs cannot evolve? Can you articulate an objective principle flowing from the concept of mutations + selection that would prevent the formation of any particular organism?Eric Anderson
October 10, 2011
October
10
Oct
10
10
2011
10:38 AM
10
10
38
AM
PDT
"If you just compare the receptors in modern humans, the evolutionary events by which they could have evolved are not obvious. It may look as if the complex functions of each protein evolved independently," said Thornton, an HHMI early career scientist and professor in the UO's Center for Ecology and Evolutionary Biology. "But when we traced these proteins from their ancestor through time, we saw how evolution tinkered with the ancestral form, producing an incredible diversity of protein functions and the ability to interact with many different chemical signals."
http://uonews.uoregon.edu/archive/news-release/2010/10/evolutionary-tinkering-produced-complex-proteins-diverse-functionsPetrushka
October 10, 2011
October
10
Oct
10
10
2011
07:50 AM
7
07
50
AM
PDT
1 … 3 4 5 6 7 … 11