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Topic: Phillip L. Engle: New Evolutionary Theory: The End of Ideology
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Rex Kerr
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Member # 632
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posted 07. April 2004 21:02
Biology is already treated as being quite nonlinear, and many aspects of it are far from equilibrium (although many fewer are far from steady-state). Aren't we already at (1), then, and can't we skip directly to step (2)?
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Phillip L. Engle
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posted 08. April 2004 09:34
We're not at (1) so long as biologists continue to stubbornly maintain (in the teeth of the facts) that the linear Darwinian re-sorting and selection mechanisms which provide for a limited range of useful variation WITHIN a species are the "very same" linear mechanisms that putatively fully explain the evolution of species, genera, etc. in the first place.
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Argon
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posted 08. April 2004 10:24
Phillip L. Engle writes:
"Such a revolutionary approach to biology would be to linear, uniformitarian Darwinism what Einstein's nonlinear General Theory of Relativity is to linear Newtonian dynamics."
I didn't realize that the General Theory of Relativity was any more or less 'linear' than Newtonian dynamics. For example, nonlinear oscillators may arise out of simple, classical systems.
I apologize for being pedantic but I don't think 'linear' means what Phillip thinks it does. Rex Kerr is correct in mentioning that biologists/biochemists/biophysicists already assume that life is not about 'linear' interactions. For example, heatbeat regulation relies on chaotic mechanisms of feedback. Even 'simple' preditor/prey interactions can create nonlinear responses. Enzyme dynamics, gene expression and many other biological phenomena are known to involve nonlinear interactions. So scientists within the life sciences most certainly are at least at step (1). About the only thing 'linear' about evolution is common (lineal) descent -- But that's another meaning entirely.
[ 08. April 2004, 11:35: Message edited by: Argon ]
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nosivad
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posted 08. April 2004 12:31
Argon
I am unaware of the "chaotic mechanisms of feedback" that regulate heartbeat. As a matter of fact, the heart without any innervation whatsoever, regulates its activity very well as is demonstrated by heart transplantation. It is know as "The Law of the Heart". The more blood the heart receives the stronger is the ventricular response. In any event please document these "chaotic mechanisms" in order to satisfy my curiosity.
As for "common descent", even that is far from established. The number of times life originated is just as unknown as how life originated. I find it very difficult to imagine evolutionary conversions between the many different life forms represented in the Burgess Shale. Leo Berg even postulated thousands of primary forms, without explaining exactly what he meant. The simple truth is, as I indicated in the paper "Is Evolution Finished?", that no one has the foggiest idea concerning events to which no one was witness. Actually, the only two things of which I remain convinced are 1. evolution did occur and 2. chance was not a contributing factor.
[ 08. April 2004, 12:49: Message edited by: nosivad ]
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Jack
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posted 08. April 2004 12:32
Hi Phillip Engle, I looked up your paper, "Teleology and Information in Biology". Unfortunately I'm unable to copy it. I'm trying to determine if I'm hitting a glitch or if the paper isn't allowed to be copied.
[ 08. April 2004, 19:36: Message edited by: Jack ]
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Rex Kerr
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posted 08. April 2004 13:45
Here's a Pubmed reference to an article on the types of spontaneous patterns generated by (obviously nonlinear) heart cells (Bub et al., J. Cardio. Electrophys. 14:S229 (2003).
There is an review article about atrial fibrillation that may be of use (Nattel, Nature 415:219 (2002)).
The heart can undergo transitions from having a stable limit cycle to being a chaotic attractor; the former is "proper" function and the latter is pathalogic under typical circumstances. Search around on pubmed for more. (here is an article that deals directly with chaos, although it is rather difficult to even understand the abstract (a Lyapunov exponent is a quantitative measure of certain types of chaos)).
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Argon
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posted 08. April 2004 14:39
nosivad writes:
"In any event please document these "chaotic mechanisms" in order to satisfy my curiosity."
That work has been ongoing for at least a decade and there is actually a scientific journal named "Chaos". In fact, the nonlinear interactions seem to be part of what helps the cardiovascular system adapt rapidly to changes in demands and loads. Rex Kerr suggested some articles and there are many more to be found using PubMed. Try "heart rate nonlinear" in a search. The following is a reference to the generalized, medically-oriented review:
JP Higgins: "Nonlinear systems in medicine", in Yale J Biol Med. 2002 Sep-Dec;75(5-6):247-60
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nosivad
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posted 08. April 2004 16:09
I am happy to learn that the "chaotic mechanisms" are pathological. However, I don't understand how this pertains to the subject of this thread which deals with why Darwinism should be abandoned as a scientific hypothesis.
"What we become depends on what we read after all the professors have finished with us".
Thomas Carlyle
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Argon
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posted 08. April 2004 16:52
nosivad writes:
"I am happy to learn that the "chaotic mechanisms" are pathological."
One can learn even more by investigating further. For example, nonlinear interactions seem to be necessary for the proper function of the heart. Some chaotic mechanisms appear to be very good for us.
continuing...
"However, I don't understand how this pertains to the subject of this thread which deals with why Darwinism should be abandoned as a scientific hypothesis."
Beats me. nosivad asked for references on the subject of nonlinear and chaotic feedback in the cardiovascular system.
As for the 'digression' about linear vs. nonlinear systems: If one checks my initial post (just scroll up a few lines), I said that I did not understand what Phillip L. Engle meant by 'linear' when he wrote of things like "linear Darwinian re-sorting and selection mechanisms" in his counter-response to Rex Kerr or when he originally used the term to contrast General Relativity with Newtonian dynamics. Clearly, considerations of linear vs. nonlinear systems have little if anything to do with arguments about the validity of Darwinian theory.
[ 08. April 2004, 17:06: Message edited by: Argon ]
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nosivad
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posted 08. April 2004 18:07
The whole thrust of Engle's essay is to question the validity of the Darwinian hypothesis. It certainly does not qualify as a theory sensu strictu. Theories are verified hypotheses. Darwinism simply doesn't meet that standard. Why it persists mystifies me.
[ 08. April 2004, 20:56: Message edited by: nosivad ]
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michaelgoodrich
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Member # 393
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posted 09. April 2004 14:03
Just wanted to throw in my $0.02 and say that I disgree with Engle in that statistical mechanics didn't introduce "chance" but rather ignorance into the existing framework of late 19th century mechanics.
This ignorance taking the explicit form of various statistical properties of large collections of molecules operating under ostensibly a purely deterministic Newtonian mechanics.
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Phillip L. Engle
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posted 11. April 2004 20:33
In describing neo-Darwinism as a "linear" theory, I am speaking in-general and overall, and I am using "linear" in the well-understood mathematical sense. In a short 6-page essay I can't nuance this. However, my 500-page book FAR FROM EQUILIBRIUM is available online for free at www.farfromequilibrium.com, and it goes into great detail on the differences between linear and nonlinear science, prior to going on to make the case for Robert F. DeHaan's theory of macrodevelopment as a proposed (essentially nonlinear) replacement for Darwin's (essentially linear) theory. (As one nuance, the book recognizes maverick paleontologist Stephen Jay Gould's advocacy of nonlinear chaos theory as relevant to evolutionary theory.)
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Rex Kerr
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posted 12. April 2004 06:22
The correct link does not have a comma in it.
I'm not sure whether this is the place to discuss the book at length.
For now, I'll mention that macrodevelopment is not only nonlinear but essentially discontinuous; and that Darwinian-style evolution is simply asserted (repeatedly) to be linear with no argument as to why it must be. In fact, I agree with a number of arguments as to why the history of life was nonlinear. I just can't see why a Darwinian-style (random mutation and natural selection) mechanism is ruled out on the basis of its imagined linearity. (Indeed, many of the arguments presented against a neo-Darwinistic viewpoint have nothing whatsoever to do with linearity.)
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nosivad
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posted 12. April 2004 07:16
The primary reason that Darwinian-style evolution must be ruled out is its failure to qualify as an experimental science. Of course it is also possible that evolution has been entirely emergent and independent of any external factors including mutation and selection. As long as speciation through experimental selection of micromutations continues to fail the second alternative remains viable. Neither can be accomodated within the Darwinian framework. Having rejected both Lamarckian and Darwinian hypotheses on experimental grounds, I am inclined toward a prescribed and self-regulating evolutionary scenario in which sexual reproduction served to terminate and stabilize speciation as well as the formation of any new higher taxonomic categories.
"Facts are facts; no new broad organizational plan has appeared for several hundred million years, and for an equally long time numerous species, animal as well as plant, have ceased evolving... At best, present evolutionary phenomena are simply slight changes of genotypes within populations, or substitution of an allele with a new one"
Grasse, Evolution of Living Organisms page 84
Please note how Grasse's statement conflicts with the title of his book.
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Argon
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posted 12. April 2004 11:21
Phillip L. Engle writes:
"In describing neo-Darwinism as a "linear" theory, I am speaking in-general and overall, and I am using "linear" in the well-understood mathematical sense."
I think I understand what 'linear' means in the 'well-understood mathematical sense'.
I concur with Rex Kerr. Neo-Darwinism is not a 'linear' theory per se (and it is not a single theory, per se). The root proposal is that interactions with the environment and inheritable variations among organisms can contribute to the differential reproduction of organisms. These interactions and the mappings between genotypes and their 'performances' in any particular environment can either be linear or nonlinear -- It depends entirely on the nature of the interactions and the underlying biology. Linear models are often used, mostly under highly simplified conditions, to make some of the work tractable. However, there is nothing inherent about neo-Darwinism that implies or requires the models to be linear vs. nonlinear. In fact, many (perhaps most?) complex evolutionary models are non-linear*. Arguing against Darwinian models on the basis of their perceived 'linearity' commits two errors: It is incorrect (Darwinian models are not inherently linear), and a non-sequitur ('Linearity' has nothing to do with validity).
For example, see here.
*(As are many models of classical dynamics. See the simple, non-linear oscillator model I referenced earlier. Weather is another classical, nonlinear, dynamic system.)
[ 12. April 2004, 11:30: Message edited by: Argon ]
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