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Author
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Topic: Phillip L. Engle: New Evolutionary Theory: The End of Ideology
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zenheadache
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Member # 1233
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posted 06. May 2004 18:42
Nosivad, I probably shouldn't be respondiong because your comments were off the point, but it is lazy to say people were born with things like political or religious views. That's nonsense. People GENERALLY adopt the prevailing political and religious views of the environment in which they grow up. That's why some states are reliably religious and conservative over time, and why others are reliably irreligious and liberal over time.
It prematurely closes off discussion when you say some can't be convinced because they are born with a particular attitude and cannot change, and at the root of every informal fallacy is an attempt to prematurely end discussion before the issue has been settled logically.
There's no reason to get angry. If others are making valid criticisms against you, it's actually an opportunity to fine tune your ideas by addressing those criticisms.
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nosivad
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Member # 767
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posted 06. May 2004 19:08
Zen It is not nonsense. Read Wright's book and then draw conclusions. Of course you will have to go to the library. I don't get angry any more. I just get disillusioned.
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Rex Kerr
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Member # 632
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posted 06. May 2004 22:37
Zen, carefully done separated identical twin studies tend to show correlations of something like 50-70% on measures of personality, political leaning (left/right), and religious fervor. See, for example, Bouchard, T.J., McGue, M., Lykken, D., and Tellegen, A. 1999. Intrinsic and extrinsic religiousness: Genetics and environmental influences and personality correlates. Twin Research 2:88-98.
There are a lot of poorly done identical twin studies, though, so keep your eyes open if you decide to glance through abstracts without reading the methods sections of the papers!
In any case, 30% variability still gives plenty of room for experience, even in personality traits. Specific beliefs are necessarily much more experience-dependent.
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Rex Kerr
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posted 07. May 2004 03:12
Hm. It's a pity that the work I'm familiar with (performed in the lab of Bernhard Palsson) isn't published yet, because it gives a nice alternate view to Lenski's study. In particular, they sequenced the entire genome of their strains after 1000 generations. They didn't pick up any hypermutators as far as I am aware. They tested for evolutionary adaptation to growth on a different carbon source, and using a constraints-based model of biochemical networks, were able to predict the optimal utilization of that network on a given medium. The E. coli rapidly found that optimum, but in their whole genome sequencing, they found that it was implemented in a variety of different ways (some mutations were the same, but others varied between strains, and IIRC there were more variations than similarities).
However, in the paper Scott linked to, there is no indication that the common gene-regulatory phenotypes referred to by Peter (and not addressed in the paper Scott linked to) are the result of common mutations. Indeed, out of the ten mutations that they found in the three or four mutator strains, none were shared.
So the picture both from Lenski's data and from Palsson's suggests that, within the constraints imposed by the biochemical and regulatory pathways in the cell, there are certain optimal settings that can be achieved rapidly (i.e. without having to evolve entire new pathways) when dealing with an extreme case of conditions that E. coli is already pretty well adapted for. Palsson's group can predict these optimal settings, and his and apparently Lenski's data are consistent with the organisms performing a semi-random walk which is constrained by selective forces to move in the direction of this maximum fitness profile.
(Incidentally, there's a quirk in Lenski's data that I'm not sure how to interpret: on the basis of increases in fitness, he predicts 10-20 beneficial substitutions per nonmutator strain. However, on the basis of sequencing, he predicts 3. I think that the whole-genome sequencing method used by Palsson's group uncovered 5-10 substitutions per strain for only 1000 generations. (Vaguely consistent, I think, with Lenski's finding of ~10 steps of improved fitness within the first 2000 generations). This suggests that there's perhaps something odd about the regions Lenski chose to sequence.)
In any case, in the absence of other papers, Peter's characterizations seem too strong--I don't see evidence that "evolution is repeating itself over and over". Rather, for a given optimization problem, there are certain physical parameters (e.g. uptake rate, nucleotide synthesis rate, etc.) that need to be altered to attain maximum fitness, but this can happen a number of different ways. This is just an extension of results for, say, antibiotic selectivity where the antibiotic targets one gene and so, naturally, the easily-obtained selectively advantageous mutation is one that alters that gene.
Now, if the natural world just involved alternating back and forth between growth on glucose and growth on lactose, maybe evolution would repeat itself over and over (in phenotype, if not genotype). But reality is a little more complicated than that.
[ 07. May 2004, 03:15: Message edited by: Rex Kerr ]
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peter borger
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posted 07. May 2004 04:16
Lenski wrote several papers over the last couple of years on his mega evo experiment. Do an internet search and you wil find them all. The two I referred to ware published in Nature, 2 october 2000, and PNAS 4 feb 2003.
I would very much like to see the sequences of the strains Rex refers to, since I expect not a lot of hypermutatore (why would you expect them?). Evolution as we observe it is nothing more than shuffling of preexisting DNA elemenst that affect gene expression. Gene expression does the trick of Darwininan evolution.
Unfolding of multipurpose genomes is mediated by other mechanisms that thoroughly shuffle the genome, in a non-random fashion. Semi-meioses is only one of the mechanisms that could explain the shuffling. Several other saltational mechanism have already been proposed in scientific literature, and the observatoins in the chromosomes can be explained accordingly.
Peebee
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gordon
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posted 07. May 2004 10:14
I have not had much time the past few weeks, but I again note Davison's false charges:
quote:
It was perfectly acceptable to allow Gordon to describe me as incompetent and to allow that ad hominem to stand even after I asked for its removal.... There is nothing uncivil about clarifying the real position of a scholar of Schindewolf's stature.
I did not describe you in any such way, and to claim otherwise is to fabricate falsehoods.
Here is what I actually wrote:
As for Davison, he stopped doing legitimate research in the late 1970s as far as I can tell. Right about the same time he concocted his hypothesis. Coincidence, I am sure.
To which you (bizarrely) responded:
"As for your comment on when I did my last significant research, that is an inexcusable personal attack and your post should be deleted either voluntarily or by the moderator."
How is it an attack to point out the truth?
You never denied that the dates were wrong, you just characterized it as an attack.
You subsequently wrote, after a rash of paranoid blathering:
"My most recent post was prompted by my having been characterized as incompetent by an anonymous contributor to this forum."
The devolution of the truth in the thread is one of the main reasons that I suspect your claims are given so little thought.
Good day to you.
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gordon
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posted 07. May 2004 10:17
quote:
Theories are hypotheses that have been verified experimentally and thereby have fulfilled the essential feature of any theory which is predictability.
Interesting. I wonder what experiments have been done to assess the validity of semi-meiosis?
quote:
I'm afraid your arguments are falling on deaf ears
Quite obviously.
[ 07. May 2004, 10:28: Message edited by: gordon ]
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nosivad
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Member # 767
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posted 07. May 2004 13:06
I have no intention of engaging with gordon except to say that to claim someone stopped doing legitimate research when that same person has published several papers since that alleged date is a direct assault on that person's competence. It is true however that every paper I have published in the last twenty years has been critical of the Darwinian model. I will leave it for others to decide the motivation for gordon's cynical evaluation of my contributions over the last several years. I'm not through yet either. I'm just getting warmed up!
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peter borger
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posted 07. May 2004 13:42
Maximal fitness?
Why don't you simple call it maximal reproduction rate?
That's all fitness stands for in the evolutionary jargon. Not that the organism are more fit, whatever it means, the organism are simply able to reproduce faster.
It should be crystal clear that every selection experiment that involves replicating organism will end up with the fastest replicator. You don't have to be an einstein to understand that.
Such experiments have NOTHING in common with evolution.
have a nice day,
peebee
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Scott
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posted 07. May 2004 19:10
gordon wrote:
quote:
How is it an attack to point out the truth?
I really expect to find a higher level of argumentation here at ISCID.
Your reasoning seems to be that if something is true, it cannot be an attack. This is an obvious non sequitur.
An ad hominem is an attack. Your attack is an ad hominem because it is directed not at the argument, but the person.
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Rex Kerr
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posted 07. May 2004 21:36
Peter, it is one of Lenski's papers that has the hypermutators. Scott linked to the paper. Go check it out if you're interested.
The Palsson group didn't find a majority of changes in shuffling of DNA elements. It is therefore not accurate to say that evolution is nothing more than this--Palsson's group has found more, namely (mostly) point mutations in the enzymes in various metabolic, transport, and biosynthesis pathways.
As to the criticism that every experiment that involves a replicating organism will end up with the fastest replicator and that this has nothing to do with evolution...that's just odd.
Firstly, life is such an experiment, and the fastest replicators don't always win. Secondly, life is such an experiment, so if there is evolution, it's got to be influenced by replication rates of organisms.
Maybe Peter meant something else, or was intending to post to another thread?
If we really must continue the character attack tangent:
Gordon, maybe you can explain, if they were not intended as a personal attack, what your sentences were supposed to mean and what they were supposed to imply? In particular, please account for the use of the sentence (fragment) "Concidence, I am sure.", as well as setting off the "Right about" dependent clause with a period instead of a comma, and the negation of "legitimate" used in your characterization. Or maybe it's better just to drop this and focus on the substantive parts of the discussion.
[ 07. May 2004, 21:36: Message edited by: Rex Kerr ]
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zenheadache
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posted 08. May 2004 00:46
Gordon, you were being sarcastic, and that can reasonably be interpreted as a veiled ad hominem. If you made such comments about me, I would feel the same way, and if I said that about you, you would also probably feel insulted.
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peter borger
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posted 08. May 2004 02:20
hypermutators induce an alternative DNA polymerase with less proofreading capacity. It is already preexisting in the genome. This is Rosenberg's work. Let me repeat this:
All elements that induce vatiations are already present, preexisting in the genome.
peebee
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Rex Kerr
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posted 08. May 2004 15:26
You might read the article--that wasn't the type of hypermutator they were scoring for.
Also, yes, everything that causes variation in an organism, with very rare exceptions, is a modification of what's already there. That's the whole point of common descent. This doesn't distinguish between modern evolutionary models and alternatives.
[ 08. May 2004, 15:26: Message edited by: Rex Kerr ]
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