Evolution Not Random

[articulett]

New Findings Confirm Darwin's Theory: Evolution Not Random


http://www.sciencedaily.com/releases/2008/01/080118134531.htm

Not that this will make any difference to anybody who thinks that it makes sense to call evolution "random" or that scientists think this all came about "randomly"-- but more proof of what the smart people on this forum have been saying all along.

I do get tired of the creationist straw man and purposeful obfuscation of what is and isn't random in regards to evolution and what "random" means.
No scientists says that evolution is random. There are random components to the mutation process... but the process itself is deterministic.

 

[Esperdome]

I recommend to anyone interested, "The Blind Watchmaker" by Richard Dawkins. It really helped me to understand the nuts and bolts of Darwinism.

 

[mijopaalmc]

Nothing in that article actually say that evolution is not random in the mathematical sense, i.e., "[o]f or relating to a type of circumstance or event that is described by a probability distribution". Evolution (in particular natural selection) can be random in that sense a still display the convergence on adaptive optima describe in the article.

The way to prove that evolution is deterministic is to come up with data that say individuals of a given group of phenotypes always reproduce while individuals of all the other phenotypes never reproduce. So far no evidence of that nature has ever been produced.

 

[Esperdome]

The way to prove that evolution is deterministic is to come up with data that say individuals of a given group of phenotypes always reproduce while individuals of all the other phenotypes never reproduce. So far no evidence of that nature has ever been produced.

From what I understand of evolution, this is incorrect. The one group may reproduce more having more favorable characteristics, but the other group will keep on reproducing, but would be slightly less likely to reproduce as the first group.

 

[mijopaalmc]

From what I understand of evolution, this is incorrect. The one group may reproduce more having more favorable characteristics, but the other group will keep on reproducing, but would be slightly less likely to reproduce as the first group.

That was my point: the authors of the reportage and the authors of the journal article are falling prey to the oldest trap (yes, that is a slight bit of hyperbole) when discussing randomness. "Random" doesn't mean "unconstrained", "unbiased", or even "equiprobable". If that were true, the vast majority of the random variables that are described by probability distributions would not be random at all.

 

[Esperdome]

I'm afraid I'm not following you, Mijopaalmc. Do you support this statement or not;

The way to prove that evolution is deterministic is to come up with data that say individuals of a given group of phenotypes always reproduce while individuals of all the other phenotypes never reproduce. So far no evidence of that nature has ever been produced.

 

[articulett]

I'm afraid I'm not following you, Mijopaalmc. Do you support this statement or not;

Mijo, like Behe, thinks that "evolution is 'random'"

This post was directed at him and his ilk. There is nothing you can say or that anyone can say that will allow him to conclude that it's misleading and nondescriptive and confusing to describe evolution this way...

He swears he's not a creationist... but he insists on calling evolution "random"... he thinks that he is being clear and that Dawkins, et. al. are incorrect. Behe thinks the same. They both believe they are being "academically rigorous" but to the rest of the world they are going out of their way to obfuscate understanding of natural selection... so that it evolution sounds difficult to understand and unlikely rather than-- well, obvious.

He's impervious. But be my guest... if you want to play a round of Kleinmanesque "dodge and weave".

 

[mijopaalmc]

I support that statement and was expanding upon it in my next post. I was saying that people who insist that evolution is non-random are equivocating in so far as the way they choose to define "random" renders most of the random variable described by probability distribution in probability theory non-random. For instance, the normal distribution, which is the staple of most basic statistic, would not described a random variable because it is concentrated around its mean.

 

[Lucky]

The article is entirely without merit (and almost devoid of information). Hopefully the study wasn't – but we'll have to read it in the November 2007 issue of Current Biology to find out. This type of article - an exceptionally silly one in this case - is generated from the press release when a paper is accepted for publication. The journalist (usually with only the most superficial understanding of the topic) does a bit of paraphrasing and condensing, and adds a few colourful and vaguely relevant phrases ("Darwin's theory of evolution", "settle the question", "significant milestone").

We really, really are not going to "settle the question" of Darwnism vs some other mechanism of evolution (still less, evolution vs creationism - though it's already been settled multiple times) from a single study of 40 defined characteristics of female sexual organ development in 51 species of nematode.

Articulett, I'm not sure why you introduced the straw man of creationism – the article didn't, and I'm damned sure the study didn't. As far as it's possible to tell from the article, the researchers were using some standard methods of multi-generational analysis of triggered mutations (in nematodes) to compare the predictions of evolution by survival/reproductive advantage with those of random genetic drift. I guess their thesis was that high correlations between the different characteristics as they evolve through the generations implies the Darwinian advantage explanation.

The main problem here is to be sure that the 40 measures are truly independent with respect to their underlying genetic basis (else some of them are redundant measures of the same genetic changes, and necessarily correlated). How well this study handled the problem I don't know.

It's also just possible (from the article) that they are claiming to have shown that the advantageous mutations themselves are correlated – which would be highly heretical.

Shame the article couldn't have told us all this.

 

[MG1962]

Does claiming evolution is random in an organised kind of way count?

 

[mijopaalmc]

Here is the Current Biology article: Trends, Stasis, and Drift in the Evolution of Nematode Vulva Development. It was published in November 2007.

 

[tuc0]

Please do not use Comic Sans

 

[Esperdome]

Thanks for the warning, Articulett. I just finished "The Blind Watchmaker" a couple weeks ago, and I'm 'crusin' for a brusin' if you know what I mean.

 

[articulett]

Please do not use Comic Sans

Oops... didn't know I was making a Faux Pas... what font should I use when I've had enough Times New Roman and Arial. I was hasty and picked the first readable but not boring looking thing from the font list. I think comic font abuse would decrease if they'd named it "Komic" sans... --further down alphabetically.

 

[articulett]

I just brought up the headline because I saw it today... and because I knew the usual suspects would interject to say that evolution really IS random.

Here's a couple of better articles.
http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=205901264
http://science.slashdot.org/article.pl?sid=08/01/18/1943255

The biggest part of the wedge strategy is to misrepresent evolution with this idea that scientists think all this came together "randomly". All scientists (except creationist) would say that is simplistic at best and leaves out the most salient aspect of evolution--namely, natural selection.

Dawkins review of Behe's book captures the misunderstanding quite well:
http://www.google.com/search?client...+behe+edge+of+evolution...&btnG=Google+Search

In my opinion, Mijo is Behesque. Enjoy.

 

[mijopaalmc]

Thanks for the warning, Articulett. I just finished "The Blind Watchmaker" a couple weeks ago, and I'm 'crusin' for a brusin' if you know what I mean.

It is so sad that many people here insist that saying that evolution is random is a creationist stance, because their insistence belies the same ignorance of probability theory and stochastic processes as creationists. What really needs to be shown is that the creationist position that "evolution is impossible because evolution random" demonstrates a facile understanding of probability and stochastic processes and that evolution can display its empirically observed characteristics even if it is random.

 

[Esperdome]

I support that statement and was expanding upon it in my next post. I was saying that people who insist that evolution is non-random are equivocating in so far as the way they choose to define "random" renders most of the random variable described by probability distribution in probability theory non-random. For instance, the normal distribution, which is the staple of most basic statistic, would not described a random variable because it is concentrated around its mean.

If you are indeed expanding, you are obfuscating. This is nothing but gobbledygook to me.

 

[tuc0]

Oops... didn't know I was making a Faux Pas... what font should I use when I've had enough Times New Roman and Arial. I was hasty and picked the first readable but not boring looking thing from the font list. I think comic font abuse would decrease if they'd named it "Komic" sans... --further down alphabetically.

I agree it's not easy picking fonts for use on the web because you have so few to choose from. Maybe Courier New... has that old school typewriter vibe.

 

[mijopaalmc]

I see that articulett is repeating here old falsehood that "no reputable scientist says that evolution is random (or a stochastic process)". This is manifestly untrue as there are a least two prominent evolutionary biologists who have said that:


Stochastic Processes and the Distribution of Gene Frequencies under Natural Selection

Evolution is a stochastic process of change in gene frequencies in natural populations. Since the populations making up a species consist of many individuals and since evolution extends over enormous periods of time, laws which govern the process of change are inevitably "statistical". In this sense the genetical theory of evolution, as R. A. Fisher (1922) suggests, is comparable to the theory of gases. This analogy can be pushed further: Instead of considering populations as aggregates of genes, we find it more convenient to consider populations as aggregates of gene frequencies (or ratios). This is similar to the situation in physics where the specification of theory population of velocities is more useful than that of the population of particles (Fisher, 1953). As far as I know, this fruitful idea was first incorporated into the theory of population genetics by Fisher in his 1922 paper, which lead to a later elaboration (Fisher 1930a).

Selection: The Mechanism of Evolution[/QUOTE]

In every generation better-adapted individuals will bee more likely to survive and reproduce. This is only a tendency, however, not a deterministic rule. A snail living in an English hedgerow is less likely to be eaten of its shell is striped rather than plain.But it is not very likely to survive in any case; it may be eaten by a shrew, or die of heatstroke or starvation; it may even be eaten by a bird after all. Selection is a process of sampling. The variation of characters among individuals ensures that the sample that reproduces is a biased sample of the population as a whole, but its composition cannot be precisely specified in advance. But there is nobody responsible for selecting snail at the bottom of hedgerow, and no individuals, no matter how well-endowed has any guarantee of success, only a greater or lesser chance. Richard Lewontin once prefaced a lecture on this topic with a quote from Ecclesiastes: the race is not alway to the swift, nor the battle to the strong; but time and chance happen to both.

The nature of evolution as sampling implies that evolution is a stochastic process that is subject to sampling error. The composition of a population at any point in time will be determined by three factors. One is historical, the composition of the generation from which it descends. The second is selection, which tends to increase some kinds of individual and decrease others. The third is chance. The actual composition of the population will inevitably differ from what we expected based on descent and selection, because the life of each individual is a historically unique succession of events who eventual outcome is influenced by a multitude of factors. The next generation is formed in a stochastic, or probabilistic, fashion from the success and failure of many such lives. We may be able to predict its average properties with some assurance, but its composition will fluctuate to a greater or lesser extent in ways we cannot predict or account for.

 

[mijopaalmc]

If you are indeed expanding, you are obfuscating. This is nothing but gobbledygook to me.

Are you sure that, much like articulett, you are trying so hard to not understand?

The authors of the Current Biology article were explicitly clear that that they were defining "random" as "unbiased":

A surprising amount of developmental variation has been observed for otherwise highly conserved features, a phenomenon known as developmental system drift. Either stochastic processes (e.g., drift and absence of selection-independent constraints) or deterministic processes (e.g., selection or constraints) could be the predominate mechanism for the evolution of such variation. We tested whether evolutionary patterns of change were unbiased or biased, as predicted by the stochastic or deterministic hypotheses, respectively. As a model, we used the nematode vulva, a highly conserved, essential organ, the development of which has been intensively studied in the model systems Caenorhabditis elegans and Pristionchus pacificus.

All that I am say is that the definition of "random" as "unbiased" is not borne out by probability theory, as the majority of random variables and their corresponding probability distributions would not be "random" if such a definition were used.