What evidence is there for evolution being non-random?

[Meadmaker]

Or that anything at all has a purpose from some point of view.

~~ Paul

Good point. "Purpose" is not an inerent part of living systems (or other physical systems, for that matter). The idea of "purpose" is imposed on a system ex post facto by an observer.

 

[Meadmaker]

Wind has no purpose--but it exists and blows dandelion seeds all over the place and so do kids making wishes... But there is no dandelion planting purpose...

Likewise, there is no dandelion planting purpose to a dandelion seed. Dandelion seeds have no purpose.

 

[articulett]

Certainly one problem with the argument is that it suggests that the complexity of the airplane couldn’t come about randomly. Most people would recognize that the error in that argument is that all of the complexity wouldn’t happen at once.

>>>. . .
All right, I addressed that one. If there's another one you would like me to address, feel free to let me know. I know you've mentioned quite a few already, but one at a time, please, if you really want to hear my answer. I'll have a few for you as we go on, but for now I'm content to answer, not ask.

Actually, most people wouldn't recognize the error in Deepak's argument--because random implies a lack of direction--and thus instantly is a possibility.

Now address the original post where mijo wants to know the evidence for evolution being non-random so that he can refute"the creationist straw man (sic) that holds that organisms in their current state are far too complex to have arisen by chance."


Once you do that, you'll have solved his dilemma in it's purported entirety. Now remember, you've pretty much claimed that "evolution is random", and the biologists here have said, actually, mutations are considered relatively random, but selection is not--it makes sure the least fit go no further (in the game of life)--and acts to hone the more fit through time--hence it's the "opposite of random"--it forces direction. In this analogy, fitness refers only to a strand of DNA's ability to make more copies of itself (on which natural selection can act).

Remember, this answer needs to be directed at hypothetical creationists, so don't assume any scientific knowledge or even an eagerness to understand the flaw in the statement. Afterwards, see if he can explain the answer back to you without being obfuscating. If not, why not? And if you can't do it, who can? See, if he can give an answer that would satisfy a biologist into concluding that he does, indeed, understand the answer to the question he asked. See if he gives an answer that shows how evolution is very different than the gas molecules he speaks of in regards to random and non-randomness. See if he gives an answer that convinces anyone that he understands the basics of evolution. And what exactly is the problem that you and he have with "random mutation coupled with natural selection"?

 

[mijopaalmc]

articulett-

In this particular case, the argument need not be directed at creationists. I started this thread because I had stated that evolution was random in another thread, provided evidence in the form of definitions that it was random and been met with staunch denial (not refutation, but denial). I therefore wanted people to present evidence that evolution is "non-random" in this thread.

 

[articulett]

Likewise, there is no dandelion planting purpose to a dandelion seed. Dandelion seeds have no purpose.

Exactly. But if genes in the dandelion could be said to have a purpose it would be to get the chance to make more copies of themselves. The same goes for a computer virus...once it's "released in the wild", it generates it's own copies (or not) by invading host machines. But, through natural selection, the dandelion has evolved an all too good strategy for making more of itself all over the place, and has been aided by human "wish making" while blowing on dandelion fluff (another act without a purpose--a meme without a theme, if you will.)

This is really one of the best brief descriptions of evolution that I could find. http://video.google.com/videoplay?docid=-522726029201501667&q=sagan+evolution&hl=en
I show it to my students and reflect back on it. He talks about chance--and about preferential survival--and how it is without purpose-- If you or Sagan or anyone else on this forum cannot get mijo to answer his own question, I suggest, it's because he wants to hear about how evolution is random--not how it's not.

BTW, I linked this before. Mijo doesn't seem interested in links that answer his topic question.

 

[articulett]

articulett-

In this particular case, the argument need not be directed at creationists. I started this thread because I had stated that evolution was random in another thread, provided evidence in the form of definitions that it was random and been met with staunch denial (not refutation, but denial). I therefore wanted people to present evidence that evolution is "non-random" in this thread.

That is because random is a word associated with chance and abused by creationists as noted in your opening post. (And by the way, you referred to the hypothetical creationist claim as a straw man, but I'd characterize it more as a misunderstanding.)

When you say evolution is random, it leads to the exact same misunderstanding. It skips over selection--the most important part of evolution--the non-randomizer--the mechanism by which evolution is a "process"--a complexity-builder. Having random components does not a random process make. A case can be made for it be absolutely wrong--or at least as wrong as saying "artificial selection" is random. Because whether selection is purposeful or not doesn't change the fact that selection is going on. Always. Not every life form survives long enough to reproduce...not every strand of DNA has an equal chance at survival and complexity formation...not every sperm makes an organism...not every seed makes a plant...whatever genetic factors made the ones that do "lucky"--get passed on. Both Dawkins and Carl Sagan point out that selection is not random--even if that is not the exact words--but you keep hearing that random components make it random and thus it's fair for you to conclude that "evolution is random"--buy why? Why would anyone conclude such an unclear thing--even if you could twist meaning in a way so it wasn't completely false--why? Especially if the goal was to show someone the non-random elements of evolution so they did presume that complexity came from chance. Chance is just a ticket in the lottery. Selection chooses which numbers come up winners.

And if people are adamant about saying evolution is NOT random, it might be because people like you keep saying it is--when that is a mischaracterization at the very best. You seem to seek out the random components and need very little evidence to conclude "evolution is random", but you dismiss all the evidence that shows that this is a really wrong misleading way to explain the process. YOU are the one stuck on that word. You are the one who refuses to see Selection as something other than random. Is artificial selection random or non-random-- and does it really matter in understanding what artificial selection IS? Natural Selection is the same thing...over longer time and with less "purposeful" choices.

Having random components does not a random process make. I wouldn't trust anyone who says "evolution is random" unless I was damn sure they understood selection. And I would prefer the term "undirected"--or "without purpose" or "without a goal"... to "random". It isn't random...just like the fly article says. I know what meadmaker means by random--but he does not mean what you do.

Complexity may come from chaos...(which also isn't random)--but evolution's complexity comes from selection.

 

[mijopaalmc]

I am cross-posting part of something that I wrote in response to one of Paul's post in another thread.

To me, if being more fit guarantees survival while being less fit guarantees perishing, evolution is a deterministic (or non-random) system. However, if being more fit only makes survival more probable while being less fit make perishing more probable, then evolution is a stochastic (or random) system because it is based on probabilities of survival whereas the former deterministic system is based on certainties. Notice that it is by virtue of the fact that the events are constrained and probabilities of survival non-uniformly distributed, which is what evolutionary biologists* seem to mean when they say that evolution is "non-random", that evolution happens in the stochastic system. If the events were unconstrained and the probabilities of survival uniformly distributed, which is what creationists mean when they call evolution is "random", evolution couldn't happen because every individual would be equally fit. Thus, in so far as evolutionary biologists mean something more restricted than mathematicians and statisticians** when they describe evolution as "non-random", the description of evolution as "non-random" is completely correct within the confines of evolutionary biology. Similarly, in so far as creationists mean something even more restricted than mathematicians, statisticians, and evolutionary biologists when they describe evolution as "random", the description of evolution as "random" is completely incorrect outside of the confines of creationism.

I thought it was more appropriate to respond what Paul said where he said it, but I still feel the above is relevant to our discussion here.

 

[articulett]

I am cross-posting part of something that I wrote in response to one of Paul's post in another thread.



I thought it was more appropriate to respond what Paul said where he said it, but I still feel the above is relevant to our discussion here.

But there is a 100% certainty that the least fit will not survive. That is the definition of least fit. Whether it's an embryo with an extra autosome or a sperm with 2 tails or a dandelion seed that remains two firmly attached to it's core. If only one male in a group has mating rights, then it won't be the least fit one, that's for sure. Fitness tends to beget more fitness--recombinations and mutations allow for growth on that theme--lesser fitness tends to get weeded out. The less fit always will. 100% of the time. We will never know all the potential "geniuses" or "fit" specimens that perished in the randomness of life--and we will never know the least fit that never got a toehold on life either. They're ancestors are not here. But we can see the "successes" in every genome. Every genome today is due to millions of years of elimination rounds... and the game is still going on.

 

[Meadmaker]

Now address the original post where mijo wants to know the evidence for evolution being non-random

Oh, that's easy.

"Yes, that's accurate, but it isn't all that helpful in understanding evolution. The important thing to understand is that even though survival in one generation is random, it is random with a non-uniform probability. Over many generations, the probability of survival of a gene with low fitness complements is so small that we can neglect it, while the higher fitness complement will certainly dominate. In fact, those probabilities are so close to 0 and 1 respectively that it's questionable whether the word "random" is even appropriate."

so that he can refute"the creationist straw man (sic) that holds that organisms in their current state are far too complex to have arisen by chance."

I make no claims for fitness of purpose of this answer. I'll just answer the questions.

Next?

 

[T'ai Chi]

Again, I agree that it's really a stochastic/random process. And if you would like to call it such when explaining it to a novice, be my guest. Then the novice can ask what a stochastic process is and expect to get a full explanation from you.

So how is it the "exact opposite of the truth", according to Dawkins, to call it stochastic/random then?

 

[T'ai Chi]

What do we say when we have a stunningly complex suite of processes that involve a good-sized dollop of randomness (mutation, genetic drift, etc.) and a much larger-sized process that is largely deterministic when looked at from the point of view of the Earth, but somewhat more random when looked at from outside the Earth? We agree that, overall, evolution is a random process.

You answered your own question. If it involves any randomness, it is correct to call it random, even if it involves the largely (phrasing which allows for yet more random stuff) deterministic.

 

[T'ai Chi]

I think it's more misleading, because you continually ignore the fact that evolution is nonrandom with respect to the environment.

IMO that's just some wishy-washy English tacked on to things. Kind of a pseudo-explanation/weasel word kind of thing to pretend that stochastic suddenly does not mean random. Like referring to philosophical debates about whether everything in the universe is really deterministic or not, it is in the same genre of a pseudo answer to this scientific question.

Talking about this scientifically, however, the pertinant issue seems to be: can anyone provide any example of a non-trivial function that has random and non-random inputs such that the function is not a random variable?

If one can't, and evolution is a non-trivial function that has random and non-random inputs, why would one believe that calling evolution random is "the exact opposite of truth"?

 

[articulett]

I am cross-posting part of something that I wrote in response to one of Paul's post in another thread.



I thought it was more appropriate to respond what Paul said where he said it, but I still feel the above is relevant to our discussion here.

But there is a 100% certainty that the least fit will not survive. That is the definition of least fit. Whether it's an embryo with an extra autosome or a sperm with 2 tails or a dandelion seed that remains two firmly attached to it's core. If only one male in a group has mating rights, then it won't be the least fit one, that's for sure. Fitness tends to beget more fitness--recombinations and mutations allow for growth on that theme--lesser fitness tends to get weeded out. The less fit always will. 100% of the time. We will never know all the potential "geniuses" or "fit" specimens that perished in the randomness of life--and we will never know the least fit that never got a toehold on life either. They're ancestors are not here. But we can see the "successes" in every genome. Every genome today is due to millions of years of elimination rounds... and the game is still going on.

And you are really missing the definition of fitness--the relativity of fitness. Something isn't fit if it cannot live to reproduce... Fitness is defined entirely by whether an organism can get it's dna into a vector so that the information is carried into the future. If it can't do this...it's absolutely out of the game. The less "fit" it is, the more quickly it will be eliminated...the more "success" factors it has, the more likely it is to be incorporated into future generations... More or less fit has nothing to do with what humans consider "fit" and everything to do with a genes capacity for building a vector that makes more genes...whether it's giant genomes like oak trees or tiny genomes like SAR11 microbe--

Watch the Sagan clip closely. Probabilities can probably be said to be a part of any system or process or anything complex--but that doesn't mean you can define that thing as "random". Random generally means that all outcomes are equally probable--or equally unpredictable...that is just not the case with evolution. We know for certain that the least fit will not survive...will not leave fossils...they are the empty spaces between branches in the tree of life.

I truly do understand what you are saying. You are saying that because randomness is involved in selection and also in mutation, it's fair to call evolution random. That is "true"--but misleading. Why, because, randomness withing a process does not a random process make. It hops right over selection...just as the creationists jump from chance to complexity and can't imagine how it can be so. You are making the same error of the supposed creationists you want to correct. If you want to understand why their claim is off-base...not correct-- murky at best...you might want to look at why your own claim is that way. If you would just hear what the rest of us are saying-- Selection IS the non-randomizer-- Just like human choice is the non randomizer in artificial selection... And even though random aspects come into play...neither artificial selection nor natural selection are random processes. Natural selection is not random for the exact same reasons that artificial selection is not random. Really. Sure, the perfect dog specimen can get hit by a car before being bred, and a growl from the female can cause a reaction int the male that makes a different sperm fertilize the egg--but that doesn't make artificial selection random. I mean, you "could" make a case for saying that it does--but why? What information does it convey? It gives a wrong impression and no information about the most important part of what the process is.

If you see hostility towards the word "random", it's because many a creationist has abused that word...Q.E.D. Even random mutations aren't strictly "random"--but they are a lot closer to being "random" than the selectin process.

 

[articulett]

Oh, that's easy.

"Yes, that's accurate, but it isn't all that helpful in understanding evolution. The important thing to understand is that even though survival in one generation is random, it is random with a non-uniform probability. Over many generations, the probability of survival of a gene with low fitness complements is so small that we can neglect it, while the higher fitness complement will certainly dominate. In fact, those probabilities are so close to 0 and 1 respectively that it's questionable whether the word "random" is even appropriate."




I make no claims for fitness of purpose of this answer. I'll just answer the questions.

Next?

Random with non-uniform probability?...Gee, isn't that, "not random". Why not just greater or lesser probability...? And by definition...the "least fit" do not survive at all...while the lesser fit have an increasing chance of being weeded out --and the most fit--even if that implies a degree of luck in the process--are, by definition, the ones that live and reproduce the most copies of themselves (and I'm referring to the genes here). This is absolutely irrespective of which "fitter genes" could have existed if not for some random "accident"--meteor--lightening strike, etc. The fittest genes are the ones that are best at begetting more of those fit genes (and mutations thereof)...and the least fit genes are the ones that can't beget at all...or that render the organism incapable of begetting copies of themselves. You've used the word random unnecessarily and even improperly--and defined least fit as still have a probability of surviving--and the most fit as still having a possibility of obliteration...but, by the definition of fitness in regards to evolution, this is not the case.

The least fit are always those genes, organisms, strands of DNA, etc. that don't make it for whatever reasons...and the most fit are the ones that make the most copies of themselves to get carried into the future. That's it. Organisms dies, but DNA lives on...if it's "the most fit" to do so...

 

[articulett]

You answered your own question. If it involves any randomness, it is correct to call it random, even if it involves the largely (phrasing which allows for yet more random stuff) deterministic.

says T'ai... the admitted proponent of intelligent design.

Thanks T'ai, but Dawkins phraseology makes much more sense if the goal is to actually understand evolution. Quit reading for what you want to hear, and get a clue. You'd think that after 10,000 posts they'd give you a free one or something...

 

[articulett]

IMO that's just some wishy-washy English tacked on to things. Kind of a pseudo-explanation/weasel word kind of thing to pretend that stochastic suddenly does not mean random. Like referring to philosophical debates about whether everything in the universe is really deterministic or not, it is in the same genre of a pseudo answer to this scientific question.

Talking about this scientifically, however, the pertinant issue seems to be: can anyone provide any example of a non-trivial function that has random and non-random inputs such that the function is not a random variable?

If one can't, and evolution is a non-trivial function that has random and non-random inputs, why would one believe that calling evolution random is "the exact opposite of truth"?

Um, because natural selection de-randomizes the random aspects? It culls from the random to build complexity? Duh? Having random components does not a random process make. Is building a house random, because you pick the nails that were on sale in a certain store on a certain day? Are you random because you randomly pop into threads randomly to insert nonsense?

(don't worry...he has me on ignore...and he only hears what he wants to hear anyhow...it's too bad really...he'd just eat up that Deepak Chopra link...)

 

[Meadmaker]

Random with non-uniform probability?...Gee, isn't that, "not random".

Not according to my textbooks.

Serious question: Have you ever taken a college level course in probability?

 

[Meadmaker]

says T'ai... the admitted proponent of intelligent design.

Just curious, T'ai, are you a proponent of intelligent design?

 

[articulett]

Not according to my textbooks.

Serious question: Have you ever taken a college level course in probability?

Yes--and Baysesian statistics. I was a Genetic Counselor.

In statistics, a random event is an event not affected by either previous or future events--all events are equally likely.

A random number generator generates numbers so there is no detectable pattern...but even that is only "pseudo random" in the strictest sense of the word random.

In layman's term, random can mean without purpose...and that can be extrapolated to apply awkwardly to selection...because everything is without purpose--but evolution depends on previous events--not all events are equally likely and, therefore, according to the science dictionary in my hand right now, selection is not random--and neither is evolution. Randomness has no "direction"--no path one can trace. Evolution does--not purposeful--but "forward" building on what works--and eliminating that which doesn't.

By the way...proponents of intelligent design usually ignore the question or answer obliquely. Those who are not proponents of it tend to be rather vocal on this forum. You suggested in an earlier thread that worshipers would be proud and speak out--that is not the case, because they know they will be dismissed in conversation (since it's a recreation of the Kleinman thread)-- One rarely comes right out and says it, and part of the wedge strategy is to try and look like a serious scientist (not that T'ai is part of the wedge strategy or trying to look like a serious anything.)

What about you meadmaker, are you a proponent of "intelligent design". If you are not, then your reaction will be much like others who are not--and if you are--you'll dance around this question.

And what is your background on science in regards to probabilities and statistics?

 

[Meadmaker]

What about you meadmaker, are you a proponent of "intelligent design".

No.

And what is your background on science in regards to probabilities and statistics?

I have a master's degree in electrical engineering. I took two classes specifically on probability. One for advanced undergraduates, and one for graduate students. In studying optimal control and non-linear dynamics I had to study random processes. Professionally, I did work on signal processing.

I've never taken a course specifically on statistics, and the only way I can reconcile what you are saying with my work is that the definitions used in statistics must be different than those used in probability.