Vicious Love

Elijah's Lamarckism isn't any faster than evolution through mutation and selection, though. Unless I've missed something, he basically believes in every aspect of evolution (of which he is aware) except the randomness of mutation.

Now, forget the fact that the combination of random mutation and natural selection provides more than sufficient explanation of our observations, and invisible Lamarckian mechanisms are a wholly unnecessary assumption. Forget the complete absence of evidence (and rather compelling evidence of absence) of some sort of mechanism by which an organism's desire to climb trees somehow modifies that organism's genes or those of its offspring. Ignore the screamingly ad hoc implications of reconciling deleterious mutations with practice-based evolution. Forget any other glaring flaws which I'm too fatigued to notice or elucidate.

What I want to know is, in no particular order, how a bacterium practices having a pore or secretion system which it does not have, how a fish practices giving live birth, how birds practice having display colors, how insects practice mimicking each other, how plants practice having flowers, how asexual life forms practice sexual reproduction, how hermaphrodites practice sexual dimorphism, how anything practices being smaller, and how and why all those wolves practiced being Pomeranians and Schnauzers.

Godless Dave

I've felt for a while that, in evolution education, too much emphasis is put on the mutations that persisted. If we were to show some examples of mutations that failed, then people would realize that mutations don't occur to match selection criteria.

For example, demonstrating that antibiotic resistant bacteria thrive even when exposed to pennicilin only shows half the picture of natural selection. The other half is all the bacteria without the beneficial mutation that were killed by pennicilin before they could reproduce.

Barbarian

Lack of mechanism in itself should not be a slam-dunk rebuttal, consider Wegener and plate tectonics. However, Lamarckian evolution plus all the facts about the role of xNA in inheritance do pose a problem, since they imply that the Lamarckian mechanism is able to perform the astounding feat of reverse-engineering the required DNA changes starting from the desired phenotypic changes. Even more, such a mechanism appears to be packed within every individual bacteria, so what we have here is a mechanism of amazing computing power hidden somewhere in the smallest living buggers money can buy. I could use one of those, preferably with schematics and architecture models and all that. Industrial-strength encryptions would be broken before lunchtime.

The matching of DNA with phenotypes feels to me like one of those problems difficult to reverse, similar to the way it is easy to multiply two huge prime numbers; at least easy compared to the difficulty of factoring the product to get the two numbers back again. DNA to phenotype is relatively straightforward, at least compared to solving the phenotype to DNA problem. Right now the task seems like unsolvable by anything else than brute force search over a phase space with a terrifying number of dimensions. If a colony of a few hundreds of billions of bacteria solve the problem in a few generations, we have a bloody miracle at hand.

I'd expect the Lamarckist to claim that there is no need to solve such an inverse problem because living things aren't striving for a certain phenotype but for any phenotype fulfilling a certain need. Such a position, however, won't be capable of generating any predictions different from mainstream ToE.

Jet Black

or that their reproduction was slowed sufficiently that they were vastly outnumbered by the penicillin resistant ones. I always think it's important to point out that premature death isn't the only way that genes can be removed from the gene pool.

TomboyMom

Elijah: Can you think of an experiment or observation that would confirm or falsify your hypothesis?

Come up with any evidence yet. Cuz, ya know, science is all about evidence.

ninewands

Errrrmmmmm ... wrong in one. That is exactly what happens. When the body's core temperature gets too high more blood is shunted to the skin in an effort to increase cooling. When the core temperature starts dropping circulation to the extremities starts to shut down. It's all regulated by the limbic system in the brain. A perfect example of this was an electric vest I saw on a show about a polar research center on Discovery. As long as the "victim's" torso was kept warm his hands and face stayed warm (+85F) in an air temp of -20F. This bears out my personal experience as a sufferer of Reynaud's phenomenon. Protected core temp equals decent circulation in the extremities, depressed core temp equals shutdown. So no ... this is NOT a Lamarckian process.

ETA: I inherited the gene complex for Reynaud's from my mother who suffered from rheumatoid arthritis ... a condition she inherited from her mother, who also displayed Reynaud's, so explain to me how that is passed on as an acquired trait through three generations.

SpaghettiSawUs

I must remember to inform my albino friend. If he avoids skin cancer for long enough to reproduce with his albino girlfriend, and then their kids come out all niceley equipped with melanin, then maybe Lamarckism r00lz.

I'll be sure to ignore his screams though, ca't have pain getting in the way of scienceyness now can we.

Wow.

Vicious Love

It could just be a random deleterious mutation. Nothing in Elijah's Bold New Science that precludes that.

Elijah

Still a physical process not a genetic one was the point I was trying to make. Wasn't really talking about Lamarckisim in that regard but the effect of the environment on the body.

Genes get passed on in Lamarchisim just like Darwinisim it's just that the origin of the (productive) genes changes come from specific physical stimuli not random mistakes in the coding.

Don't know enough about Reynaud's disease, but it looks like a circulation problem that's connected with the cold. In a Lamarckist view at some point your/parental line's genes were trying to overcompensate for being exposed to too much cold or the genes have been overly silenced/suppressed by not being exposed to enough extreme cold for some generations so the body doesn't think that it needs to defend from the cold as much.

Coming from a line of warm/tropical lived people would eventually produce genetic traits that made living in the cold weather more difficult.

Darwinians would say it comes from a random mistake in the coding that will eventually be weeded out of the population, which it very well may be, but this was just to compare lamarck to darwin thinking.

ninewands

My point was that it is a matter of the brain's limbic system striving to regulate core temp. Take that load off the limbic system and there is no shutdown or vasodilation. Now, I'll grant you that there exist Inuit tribes up around Ellesmere Island and Hudson's Bay who do not require quite as much in the way of protective clothing to maintain circulation in their extremities as we silly Northwest Europeans do. However, this is purely a case of natural selection magnifying a modification that was originally wrought by random mutation.

Nothing forced those Inuit to stay that far north as far as I can determine. Now, this evolutionary change took place over many generations, but it was rather quick as evolutionary changes go because those who did not carry the mutated gene did not reproduce very successfully after they froze to death.