Happy Lamarck Day

How nice. My birthday.

;^)

Congratulations to both of you!

When I introduce evolution by starting with Lamarck I always say what a shame it is that the only thing we remember about Lamarck is his one mistake. The reality of it is that his "mistake" was simply a first try without which it is possible Darwin would not have developed his theory. After all Darwin did start out as a "creationist" and accepted stasis in species. The very idea of change in species was a great breakthrough in thinking. His daughter was right!!!

I think Lamarck has gotten a bad rap to a great degree. Partly because he was wrong about a key point, and partly because Charles Darwin, many years later, explained the idea of natural selection so clearly. But if you read Lamarck and try to appreciate the context of the times he was in and what was known, he did a much better job than we usually grant.

With the edition of Epigenetics to our understanding of evolutionary processes, Lamarck may not have been quite as wrong as he once appeared.

http://www.pbs.org/wgbh/nova/sciencenow/3411/02.html

Lamarck's name is associated with the testable hypothesis that the sole or major reason for adaptive variation over generations is, to put it in modern terms, some sort of direct feedback from environmental conditions, acting on the germ line and causing guided changes in germ line genetic material, to the effect that offspring would develop a phenotype better able to deal with that particular environment.

(This is, of course, a simplifying paraphrase, and this exact wording would never be found in any original writing by Lamarck. It is, however, broadly consistent with his views, and with what the term "Lamarckism" means in modern discourse. If, in fact, this paraphrase is not fair, I welcome feedback, will correct it, and will not use it going forward.)

Stated this way, the hypothesis is testable, and it is invariably found to be incorrect. The specific way in which it is incorrect is that actual germ line genetic mutations show no evidence of being "planned" or "guided" according to the human-perceived "needs" or "desires" of ancestor organisms.

That particular hypothesis was a reasonable one when Lamarck lived. In fact, it is so intuitive that it remains more or less the intelligent layman's idea of how evolution works. The reason "Lamarckism" is specifically taught as a wrong idea is probably related to the fact that it is a common and intuitive, but ultimately erroneous, interpretation of the data. Lamarck should be remembered as a brilliant scientist.

Of course, in the modern era, we know that it is foolish to think of genetics and environment in isolation from one another.

There are plenty of examples of more or less pure evolution due to "random variation and natural selection". An obvious example is single-allele-based resistance to a suddenly pervasive environmental pathogen, toxin, or antibiotic, where the resistance conferring allele is relatively rare before the sudden introduction of the challenge. This often involves a lot of lateral transfer of genetic material in prokaryotic populations (as opposed to diploid eukaryotic populations), but the bottom line in these types of situations is usually that there is rapid selection for the resistant phenotype, and a rapid change in the frequency of the resistance associated allele in the population.

On the other hand, evolution is usually the result of many more complex, interacting factors. Thus, it is common for terms like "neo-Lamarckism" to be used to discuss models in which the role of natural selection is less dominant. It should be remembered, though, that direct "guiding" of germline genetic mutations by the human-assumed "needs" or "will" of organisms has never been observed, and that we now have better explanations than that (which were not available to Lamarck).

But if you read Lamarck and try to appreciate the context of the times he was in and what was known, he did a much better job than we usually grant.

It should be noted that, in later editions of his book, "On the Origin of Species," Darwin assigned a role to inheritance of acquired traits as an engine of evolutionary change.

I should add to all of this that Lamarck's idea was not inheritance of acquired characters, but using it as a mechanism of evolution. In Lamarck's day almost everyone believed in inheritance of acquired characters -- it was obviously true. They didn't need Lamarck to tell them about it. If you had said to them "Oh that's Lamarck's idea"
they would have said "La-who? Never heard of him." Everyone knew it was true, and Lamarck's role was to make use of it, not to be a principal advocate of it.

Henry J said:

But if you read Lamarck and try to appreciate the context of the times he was in and what was known, he did a much better job than we usually grant.

So it's a case of everybody makes mistakes, and everybody has those days? :) I guess this is analogous to things like phlogiston, ether, wave-only theory of light, particle-only theory of light, various early models of the atom, and the steady-state models of the universe - all of those looked reasonable at one time to the people (or some of them) at the time. Henry

Funny thing is, you don't see anyone trying to push his ideas into public school science classes.

Joe, or anyone:

I'd be interested knowing the degree to which Lamarck postulated branching evolution. If speciation happens, as he proposed, there must be at least some amount of divergence. Did Lamarck accept common descent within genera? Within orders?Of course, even if there is branching within orders, there could be many independently derived clades within those orders, each of them with a piece of the order. This wasn't his focus, but how much evidence is there of his thought on the branching question? (To be clear: I'm not talking about tree metaphors, or embranchements, or anything except common descent of multiple species.)

Karen S. said: Funny thing is, you don't see anyone trying to push his ideas into public school science classes.

John Harshman said: Joe, or anyone: I'd be interested knowing the degree to which Lamarck postulated branching evolution. If speciation happens, as he proposed, there must be at least some amount of divergence. Did Lamarck accept common descent within genera? Within orders?Of course, even if there is branching within orders, there could be many independently derived clades within those orders, each of them with a piece of the order. This wasn't his focus, but how much evidence is there of his thought on the branching question? (To be clear: I'm not talking about tree metaphors, or embranchements, or anything except common descent of multiple species.)

There would be good reason to crown Darwin the Copernicus of biology too, if Mayr is correct to claim that he was the first to posit branching evolution. (People who recall Lamarck’s branching diagram may dismiss Mayr’s surprising claim out of hand, but the presence of extant groups along the trunk and branches of Lamarck’s tree signals how confused was Lamarck’s view, due to the lingering influence of the old chain of being as well as his reluctance to believe in extinction.)

Is there any particular reason Lamarck's "wrong idea" couldn't turn out to be right in some hypothetical creature? Suppose Planet Y has environmental factors, such as a lot of ionizing radiation, which tends to cause lots of mutations. Could mechanisms designed to repair genetic mistakes somehow themselves evolve to cause mutations of the "stretching-giraffe" variety - sort of auto-genetic engineering?

Pretty science fiction-y, I suppose: is it even possible? I'm an aerospace engineer, not any kind of biologist, so if you have an expert answer please try to pitch it in layman's terms as much as possible.

Alan Smithee said: Is there any particular reason Lamarck's "wrong idea" couldn't turn out to be right in some hypothetical creature?

* Darwin did much to make the concept of evolution respectable, but his mechanism, natural selection, proved harder to sell. Sensible people willing to question what they are told are unlikely to accept evolution by natural selection on first sight. The evidence for it tends towards the indirect, the concept has its seeming implausibilities, and some of its implications are unsettling. However, nobody has been able to suggest any other mechanistic theory for the evolution of life that has stood up to the available evidence. Lamarckism a popular idea even in the scientific community up to about World War II, but it was effectively dead at that late date and now survives only in a ghostly fashion on the scientific fringe. Lamarckism envisioned adaptations as arising in a "directed" fashion due to the "needs" and "strivings" of organisms, with these adaptations passed down to following generations. The giraffe, in stretching its neck, would get a longer neck, and would pass that longer neck down to its offspring. In terms of what we know about biology today, such notions are completely unrealistic. An organism's capabilities are essentially fixed by its genome at conception. This is not to say that an organism is as fixed in structure as any machine rolling off the production line, only that the organism is dealt a particular set of cards at the outset and its life will be a game played with those cards. The organism has no way of adding cards to the biological hand it is dealt; its progeny will be dealt a new hand of cards, reshuffled in sexually-reproducing species through sexual recombination, and with occasional variations due to mutation. The parent has little or no control over how the cards are dealt, and the hands passed off to its offspring are not necessarily an improvement on the hand originally dealt to the parent. Even if an organism did acquire new biological features, it has no means of passing them down to the next generation. The mechanisms by which genes code an organism are complicated enough; it's very difficult to suggest in any detail a mechanism that could "edit" the genome in the germ cells of an organism to track changes in form of the mature organism. This "editor" system would have to have some "blueprint" of how the organism was put together, and would have to "scan" the entire organism to see how it conformed to this blueprint. When the modifications due to the efforts of the organism to, say, stretch its neck were uncovered in the scan, the editor would have to then make the appropriate updates in all the genomes of the germ cells. Once again, the genome is far more like a recipe than it is like a blueprint and the alterations would not be straightforward. This system isn't ruled out by the laws of physics, but it would be extremely complicated in its implementation. A similar observation could be made about the origins of innate instincts. In Lamarckian terms, instincts in animals arose from behaviors learned by their ancestors and passed down, but that would imply some scheme for translating the memory of the ancestor into genetic codes. In any case, if such an editor system existed, there would certainly be some biochemical evidence for it, but no evidence has been found for a trace of it. Worse, acquired characteristics are not necessarily good; if an animal loses an eye, how would the editor know this was something undesireable? The editor would have to be able to make value judgements, determining what new features amount to improvements and which amount to defects. In MET, the value judgement is automatic: if a change improves the odds of survival and procreation, it's retained, otherwise it dies out. In addition, while it is possible to imagine a giraffe getting a longer neck by its efforts, anyone who's ever worked as a problem-solver knows that problems in themselves do not necessarily suggest obvious solutions, that obtaining solutions may require considerable mental gymnastics, and there may be different possible solutions. Would the editor dream up a list of different possible solutions, and then perform value judgements to figure out which was best? If it just came up with a solution at random and tried it, that would sound something more like natural selection at work. Carrying this thought further, how could Lamarckism create a complicated organ like the eye, or even a simple eyespot? How could a blind creature "strive" to see? The editor would have to be capable of considerable imagination. * There's a bit of fine print in this overall condemnation of Lamarckism. There has been some disputed evidence that acquired immunities in a parent can be passed down to offspring by some mechanism, which doesn't seem at all implausible. If it does happen, it would be an example of limited inheritance of acquired characteristics at work. It is definitely known that a mother will pass down a sample of the bacteria in her gut to her baby at birth, and since the mother may have acquired new and "improved" bacteria since her own birth, that would amount to inheritance of acquired characteristics -- at least through a symbiotic "end run". Of course, memes amount to inheritance of acquired characteristics, with learning acquired by ancestors passed down to descendants -- but this is blindingly obvious and nobody sees it as any challenge to MET. Memes aren't an irrelevant consideration by any means, human culture being a clearly important subject, but in strictly biological terms they're outside of the domain of concern. Nobody's seriously claiming that Lamarckism is right after all. Even adding these conditions, it's still mostly wrong.

Alan Smithee said: ... Could mechanisms designed to repair genetic mistakes somehow themselves evolve to cause mutations of the "stretching-giraffe" variety - sort of auto-genetic engineering?

As a poster mentioned here Darwin did say children could inherit developed traits of their parents. I know he said women in later life could raise the intelligence of their later born daughters by becoming smarter themselves. So a woman of 28 could by effort make her self more intelligent then her own inheritance from her mother by principals of intelligence raising. Then give to a daughter and that girl would genetically have greater intelligence. this he suggested in order to raise womens intelligence to higher levels and maybe male levels.
His ideas not mine.
Biblical creationist don't and can't agree with different intelligence levels of people. the soul is the real origin of thinking and not a physical thing is involved in intelligence.

Actually this creationist accept innate triggers to change creatures quickly in a post flood world. So within a few hundred years from one kind off the ark you would have bears, dogs, seals and others. Of coarse water mammals from land creatures and marsupials from placentals.
All creature change is untested hypothesis by the way.

John Harshman said: I'd be interested knowing the degree to which Lamarck postulated branching evolution. If speciation happens, as he proposed, there must be at least some amount of divergence. Did Lamarck accept common descent within genera? Within orders? Of course, even if there is branching within orders, there could be many independently derived clades within those orders, each of them with a piece of the order. This wasn't his focus, but how much evidence is there of his thought on the branching question? (To be clear: I'm not talking about tree metaphors, or embranchements, or anything except common descent of multiple species.)

In fact, if it is true that all living bodies are productions of nature, we cannot refuse to believe that she could produce them only successively, not all at once at a specific moment. Now, if she created them one after the other, there is reason to believe that she began exclusively with the simplest and did not produce the most complex organic structures (in both the animal and plant kingdoms) until the end.

While this order will better set down the order of nature, it will at the same time make the study of objects much easier, will improve our understanding of the organic structure of animals, the progress in its complexity from class to class, and will demonstrate even better the affinities existing between the different degrees in the make up of animal organization and the external difference which we most frequently use to characterize the classes, orders, families, genera, and species.

Such might be the reflections which one could make if man, considered here as the preeminent race in question, were not distinguished from animals except by the characteristics of his organic structure and if his origin were not different from theirs.

So within a few hundred years from one kind off the ark you would have bears, dogs, seals and others.

— Robert Byers

eddie said: The following is based on a very quick perusal of Zoological Philosophy in translation.

Lamarck explicitly rejects the Chain of Being vision, stating that life should not be studied from the 'most perfect' to the 'least perfect' since that's not the way it evolved. Instead:

Now, if she created them one after the other, there is reason to believe that she began exclusively with the simplest and did not produce the most complex organic structures (in both the animal and plant kingdoms) until the end.

As for common descent: yes, definitely. Although it appears that this is not from one original parent, but from two simple types of parents, one simple plant type, one simple animal type: As has been noted above, there doesn't seem to be any extinction in Lamarck, so from these original simple plants and animals everything we see around us has now evolved. But the immediate ancestors of everything are still around too. This accounts for the vast array of different species in the world. ... But you have to remember that all intermediate stages (or, at least, the majority of them) are still with us. However, his presentation is in table form, not diagrammatic, so it's not clear if he ever pictured evolution in a tree-like way.

This is most clearly visible when Lamarck names the ancestor for human beings: 'The Orang of Angola' (Simia troglodytes), so our ancestor is definitely still around.

Woops, I meant to say “page 462 of that Google Books version”

This book seems appropriate. Has anyone read it?:

Richard W. Burkhardt, Jr. The spirit of system : Lamarck and evolutionary biology. Cambridge, MA, Harvard University Press, 1977. (second edition in 1995). Google books has excerpts, and it says that my understanding of Lamarck is all wrong, but the excerpt unfortunately doesn't tell me what understanding would be all right. But apparently Lamarck didn't think that new lineages were arising all the time by spontaneous generation and then entering into Lamarck's branching pathways of upward development.

Frank J said:

So within a few hundred years from one kind off the ark you would have bears, dogs, seals and others.

— Robert Byers

OK, just a little feeding: Speaking of untested hypotheses, yours is one that screams for testing, if anyone indeed finds it the slightest bit promising. I would ask why you think mainstream science does not bother, but I expect you to whine about "naturalist bias." Which is pure nonsense because such a theory would be every bit as "naturalistic" as the one we have, and many "Darwinists" are even more adamant that "Goddidit" than the average promoter of the "unnamed intelligent designer." So I'll ask why you think that the DI, and specifically its "research" arm, the Biologic Institute, has yet to go near such an intriguing alternate hypothesis. Could it be because the only potential alternate explanation they have offered to date includes a ~4 billion year history of life with common descent? Could it be that, when they're not playing "don't ask, don't tell," they practically admit that such a hypothesis is absurd?

Byere wrote:

"there are many avenues to discovery . Hypothesis is one and whether its tested or not doesn’t take away from its credibility as a idea. Evolution, I say, is untested hypothesis but still its an idea that is plausible where origins start without the bible as a witness. i’m a biblical creationist and not I.D. Allies but a different army."

0.6 no information content blatantly false claims immense gramatic and spell problems epic fail