Talk:Lamarckism

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[edit] Stylistic concerns

A blacksmith, through his work, strengthens the muscles in his arms. His sons will have like muscular development when they mature sounds much better to me than similar muscular development, although I admit the use of "like" in this manner is perhaps a bit archaic or at least not widely known in American English. --Marshman 17:11, 11 Mar 2005 (UTC)

I confess similar sounds much more familiar and much better to me than like, although I admit I'm not a native English hearer. --KYPark 03:37, 9 Apr 2005 (UTC)
As I said, that use is an older, but very correct use of the term "like" in English, and still used in the sciences. The meaning is "similar". Unfortunately, the word "like" is much abused in modern American (has become a slang expresson), and many people have very different experiences with it. I for one prefer not to write to the lowest common denominator (I think there is a Simple English Wikipedia for that). The fact that "simlar" sounds better to you just shows limitation in your experience with English (which you admit); but none of us should just accept limitation. Reading should expand our experiences. Coinsider that you have now learned another correct use of the word "like". --Marshman 19:26, 9 Apr 2005 (UTC)
I think it sounds better regardless. A side note: the Simple English Wikipedia has long struggled, and I doubt that it will last another year. So Wikipedia itself may one be forced to consider and cater to that denominator. --Maru (talk) 23:58, 27 September 2005 (UTC)

[edit] Respect....

I changed the intro to: Lamarckism is a theory of biological evolution proposed by French biologist Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck. Developed in the early 19th century, Lamarckism holds that traits acquired (or diminished) during the lifetime of an organism can be passed on to the offspring. Lamarck based his theory on two observations, in his day considered to be generally true:

...as I believe Lamarckism is not a "discredited theory" any more than Darwin is "discredited" for some of the things he said in "Varieties..." Msr.Lamarck was a true genious of his day and the intro as previously written was not objective enough.

For that same reason I deleted the link to "Obsolete Scientific Theories" though I might have been a little hasty in that. (spirit of free speech and all) I'll try to replace it.

Further, I strongly object to the phrase: the main argument against Lamarckism is that experiments simply do not support the second law—purely "acquired traits" are not inherited.

Evolution of any sort generally takes eons to accomplish. I cannot conceive of an experiment that would definitively show that minor allele modification or genetic drift is not accomplished in this manner. Could someone please cite work of this sort? --LeonardM 23:23, 27 September 2005 (UTC)

Nice to see a fellow Brin-ler on here. I'll only reply to the last point: if Lamarckism takes a similar amount of time to shift allele frequencies in a population, it becomes extremely difficult to distinguish from a Baldwin effect, and secondly, regular evolution can be seen in only a few generations under sufficiently extreme selection pressures (like those which have been effected in laboratories), so given a real effect which one can see, versus an effect which is not detected, and whose supporters kept inventing excuses.... Well, one can see why naive Lamarckism was dismissed, in addition to a lack of decent explanation for how changes to somatic cells can be reflected in or transmitted to germ-line cells. Although of course there is the objection that mere "augmentation" and "diminishment" cannot generate the novelty of nature, or indeed any novelty at all. But this is not my field, so I'll hush up now. --Maru (talk) 23:58, 27 September 2005 (UTC)
Thanks Maru, same here! Just wait until I get my Blind Cave Tetra experiment going. Shoot, they might be especially susceptable to *morph-ability* in general. I'll let you know in about 20 years! --172.133.136.193 13:56, 29 September 2005 (UTC)
I think you forgot to login there... I shall look forward to reading your results in a vanity press-published book filled with long rambling screeds and incoherent essays, punctuated by occasional fits of idiosyncratic grammar and spelling! :) --Maru (talk) 06:07, 1 October 2005 (UTC)
Wow, sorry Maru. I didn't mean to sully the entire Wikipedia with my presence. ..and Gosh, I didn't think my edit was THAT out of line. but ..well, since you're an ArchBishop or whatever in the WikiCatholic church, I'll take your word for it. I'll examine my conschins, I mean Con-Sh*t and resolve not to WikiSin any more. OK? --LeonardM 02:49, 3 October 2005 (UTC)
Go my child, go and sin no more. Read the Holy Texts and receive the balm of the Holy Spirit unto thy mind, and the Great Jimbo shall receive you unto His bosom. --Maru (talk) 03:47, 3 October 2005 (UTC)
Darwin said something like "A book from which I learned nothing (I remember my surprise)." David R. Ingham 22:22, 19 October 2006 (UTC)

[edit] Lamarckism Obsolete??

LoL, Revert it back if you like. I don't have time to go to the mats on it right now. Mark my words though, epigenetic influence will prove a stronger drive to evolution than the blind random chance that Darwin so strongly advocated. (whatever the heck THAT is! :) LeonardM 18:34, 11 October 2005 (UTC)

[edit] References

Could this article be better referenced? Even if some external links were added? --Nicholas 22:35, 12 October 2005 (UTC)

[edit] Lamarckism disproven?

This seems inaccurate to me. Lamarckism in a wider sense may have been demonstrated to be unlikely/ dominated by other processes/ not happen but to say it is disproven is surely bunk. In the world of bacteriology Lamarckism is alive and kicking -- where it has been argued that bacteria can "learn" resistance from one another and then pass that "learning" on to future generations [1]. In the words of Salvador Luria: "bacteriology is the last stronghold of Lamarckism" (although he himself did not believe Lamarckism to hold for bacteria). The Encyclopedia Britannica comments that the process also holds for some protozoa[2]. Coricus 06:13, 30 January 2006 (UTC)

Will "superseded" do? Vremya 08:20, 30 January 2006 (UTC)]]
That seems fair -- but must apologise... I performed an edit on the page to add information about J. Cairns (et al) and removed your update. Please have a look throughthe article and see if its acceptable. Thanks.

Coricus 09:04, 30 January 2006 (UTC)

[edit] Article Merger

I know the scientists out there aren't likely to be happy about this but I think we should at least debate whether the article on racial memory should be merged into the one on Lamarckism. If science doesn't stop new-age pseudoscience from taking older discredited scientific theories and running with them (by simply changing the words to something else) then it loses its best facet -- the ability to educate and lift everyone's level of knowledge. Coricus 09:40, 30 January 2006 (UTC)

I actually think there are a whole range of articles here that need to be reorganised. See my suggestion of merging epigenetics and epigenetic inheritance. Would racial memory fit better there? I also feel very strongly about debunking the myth that Lamarckism is obsolete. It has actually had quite some support in recent years (see my recent edit of that article and this one), although evolution as per the modern synthesis is definitely the dominant force (also see nature vs. nurture). - Samsara contrib talk 13:49, 31 January 2006 (UTC)

I am adimantly against merging these articles. It seems today that too many historical and scientific theories are grouped together because they are now deemed false, lessening their importance. Racial memory has many implication Lammarck's biological theory does not. I vote against merging these two articles, though I know this is not democracy. Hummel

Redsupremacy says:

I have streamlined racial memory so it makes more sense, though i know think they should be kept seperate.

[edit] acquired characteristics, Darwin's pangenesis

I'm copying this discussion here as it may be useful in writing this article. It comes from Talk:Natural selection originally. - Samsara contrib talk 17:41, 19 February 2006 (UTC)

"Darwin, moreover, had also to overcome the then dominant view that individual organisms can transmit to their progeny modifications elicited in them by environmental factors. In contrast, Darwin argued that adaptation is the result of the culling by nature of inheritable variation that arises without directionality."

As far as I know, Darwin did accept the transmission of "somatic" modifications, he proposed pangenesis, his own idea of that. Thus accepting then that the modification could arise directionally.

But with natural selection taken in consideration, acquired characteristics, by itself, were not the main mechanism driving the evolution of adaptations. Along with that, there was the point that the environment is limited (Malthus influence), and those who are better adapted would succeed reproductively with more ease, outnumbering the lesser adapted variants, and eventually only the better adapted ones would exist.

Only with the rediscovery of Mendel's works with heredity that the inheritance of acquired characteristics was finally abandoned. Initially Mendel's genetics were also seen as a trouble for natural selection, by some. However, nowadays there's the myth resulting from oversimplification and historical incorrectness that Lamarckism and Darwinism conflict each other in the sense of "natural selection of non-acquired characteristics" versus "transmission of characteristics acquired by individual effort".

Even though Darwin received a letter of Mendel himself, as I've read it or heard it, he never opened, for some reason. Mendel's genetics remained unknown for some more time, and were never defended by Darwin. (I guess I've read that on Carl Zimmer's "at the water's edge", but I've also read something that makes me suspicious, I guess that was in wikipedia, about Darwin citing some of Mendel's papers.

--Extremophile 21:47, 17 February 2006 (UTC)

That is a reference. Michael T. Ghiselin is a well-respected evolutionary biologist. - Samsara contrib talk 22:35, 17 February 2006 (UTC)

[edit] Lab mice

This year, a group of British(?) scientists did an experiment that showed that a female mouse put under a lot of stress would produce offspring that exhibited a stronger perpensity for stress and anxiety than the offspring of a mouse that was kept in calm and relaxed conditions.

I believe that they found actual verifiable chemical changes in the mice born from the stressed mother that were not the result of learned behavour.

I know that this isn't the same thing as new a genetic trate being passed on, but it seems like a fringe example of Lamarckism?

If it is, could somebody please find some data on it (sorry I don't have any more information to proffer) and add it to this section as it turns around some of the agruments pressed on this page about this princple being pure hockum.

Can we have some supporting references for this and include it, please? Also, I'm not convinced by the piece on lab rats already in the article. This really needs supporting sources or it should be removed. At present it smacks of new ageism and pseudoscience... 193.129.65.37 08:22, 21 June 2006 (UTC)

[edit] Reverse transcriptase

At the viral level, apparently there's a set of enzymes called Reverse transcriptase enzymes. These transfer from the RNA back to the DNA, and may be responsible for the way viruses 'jump' species. Wonder if anyone would like to source this for this article? Seems like the one area where Lamarckism might be relevant and true.ThuranX 03:42, 13 April 2006 (UTC)

[edit] Footnotes

I have 'updated' this page to place footnotes in the current Wiki format. Also deleted an external reference to a site that is by subscription. Comments on doing this would be appreciated [I am new to this]. --Dumarest 16:26, 22 April 2006 (UTC)


[edit] Bacteriology is the last "stronghold" of Lamarckism cf. Weiner-Novick's experiment, 1957 and the experiment of Melvin Cohn and Kengo Horibata

I found material that shows that Bacteriology is the last "stronghold" of Lamarckism, namely the E.coli which are discussed :

Autrans Proceedings, epigenomique.free.fr/Cours_HN/Multistationarity.pdf

Epigenesis and the lactose operon: importance of a positive feedback circuit.

The experiment was reported by Novick and Wiener in the famous journal “Proceedings of the National Academy of Sciences US” [4]. Lactose utilisation by the bacterium E. Coli had been studied for some time in the Pasteur Institute. It was known that lactose catabolism required both an enzyme (the β-galactosidase) that degrades lactose and a permease that facilitates its penetration into the cells. Both proteins were not synthesised by the bacteria unless lactose, designated hence as the “inducer” of this synthesis, was present in the culture medium. Novick and Wiener evidenced an epigenetic modification when the bacteria were grown in the presence of a low concentration of lactose, which was not sufficient to induce the synthesis of the two proteins.


However if the cells had been previously induced (by a high concentration of lactose in the medium, but

for as short as 10 minutes), they could synthesise the proteins in the presence of the low lactose concentration for (at least) 150 generations. Thus the phenotype of the same bacteria with regard to the production of β-galactosidase, was different in this culture medium (with a low concentration of lactose) depending on whether they had or not experienced during 10 min, 150 generations ago, a high concentration of lactose. This is a wonderfully simple but quite typical epigenetic modification. And the consequences are not trivial. It means that the phenotype of this extremely well known bacterium, whose genome has been fully sequenced, is still not predictible, when the bacteria are in a medium containing a low lactose concentration if the history of the culture is not known!


Now, as everybody knows, the mechanism of the induction by lactose of the synthesis of the proteins required for its metabolism was unravelled by Jacob and Monod [5], who were awarded the Nobel prize for their now famous “operon model”. Fig 1 depicts the mechanism as it is established now. In the absence of lactose a negative regulator, protein LacI, which is always produced due to the constitutive expression of gene lacI , is active and prevents the expression (transcription followed by translation) of three genes including gene lacZ encoding the β-galactosidase, and lacY, encoding the lactose permease. In the presence of lactose, a derivative of this sugar (allolactose) has a high affinity for protein LacI and provokes an allosteric modification of this protein that looses its affinity for the promoter of the operon, which can thus be transcribed. When there is no more lactose, protein LacI resumes its active conformation, and the synthesis of the enzymes is rapidly interrupted. But how does lactose enter inside the cells? When the external concentration is high, it can diffuse through the cell wall, but this process is not sufficient at low lactose concentration. This explains why, in general, bacteria cannot be induced by low lactose concentrations.


Let us now go back to the Novick and Wiener experiment. At low lactose concentration, the cells cannot be induced, but pre-induced cells have produced a permease that allows lactose transport into the cells even at low concentration! So all that is to the epigenetic behaviour is that the permease allows the entrance of lactose that allows the synthesis of the permease etc…From this simple fact, arise all the properties of epigenesis: the phenotype (with regard to β-galactosidase synthesis) depends on the history of the culture, a short pulse of a high concentration of lactose (or a transitory removal of lactose) suffices to change one of the phenotype into the other, and there is hysteresis, since the concentration required to induce the culture is much higher than the concentration below which the cultures is “de-induced” (fig 2).


All these properties are those of a bistable system, a non linear dynamical system with two steady states. And all these properties result from the fact that the lactose permease promotes its own synthesis under low lactose concentration, that is, lactose permease is part of a positive feedback circuit.

Links:

1. Enzyme Induction as an All-or-None Phenomenon -- Novick and Weiner , 1957 www.pubmedcentral.nih.gov/articlerender.fcgi?artid=528498

2. "Physiology of the inhibition by glucose of the induced synthesis of the beta-galactosideenzyme system of Escherichia coli." , Melvin Cohn and Kengo Horibata http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=290602&tools=bot

[edit] Article merge?

There's currently an article on 'Inheritance of acquired characters' which is quite a short stub. I'm a bit confused, please ignore my ignorance if i am displaying any, but why is there two articles on what appears to be the same thing. Are Lamarckism and the theory of acquired characteristics different because as far as i can tell they relate to the same thing. If they are different, are they different enough to qualify being two separate articles or could they be merged into one? Thanks, Gazzelle 15:23, 10 January 2007 (UTC)

The Theory of acquired characteristics seems to be about the general idea throughout history and the many different proposals, and this article about Lamarck's specific theory. --Gwern (contribs) 18:19 10 January 2007 (GMT)
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