Lamarckism still here

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    • #560
      protozoan
      Participant

      Is lamarckism stil accepted in the modern biology, is there stil any minority of biologists which still believe that if i will learn hard to play on piano and finelly i will be a very good pianist (with a very good music sense), my children could inherit it?

    • #20638
      Chris4
      Participant

      Never heard of this term but i see the principle. But if i was a great on the piano i would be playing it when my kids grow up and therefore they would learn it. You’d have to find the gene for good musical abilities and see if it was passed down. Assuming there is one.
      skills such as musical abilities, sports etc can be passed to children but i think Nurture (The environment in which your kids grow up in) has a bigger role to play in this.This is the way scientists are thinking now. Nature vs nurture.

    • #20640
      DevGrp
      Participant

      Lamarck was a French botanist who is most famous for his theory of “inheritance of acquired traits.”

      The school book example of this is that a giraffes acquired a longer neck by stretching for food on high branches. It then passed this longer neck onto its childern and thus over time giraffes got longer and longer necks

      see
      http://www.ucmp.berkeley.edu/history/lamarck.html

      I did find this

      quote :

      “There is a modern form of Lamarckism, however. It holds that, as a result of an animal’s practice or habits, its hormones are changed. This results in inheritance by the offspring of the variations thus called forth by the parents’ adaptation to environment. Imagine a bird which must walk in shallow water and must continually attempt to stretch its legs. Its hormones, they say, will become modified by this practice. Its eggs are then supposed to be influenced by this hormonal change. The offspring will tend to have longer legs as a result, according to modern Lamarckism”

      The author references an obscure 1960’s French book as the source of this theory

      Of course the web address I found this on says it all:
      http://creationsafaris.com/epoi_c05.htm

      On the other hand I have a bit more respect for SCIENCE

      quote :

      Recently, however, Lamarck’s name has been creeping back into the scientific literature. The reason: an explosion in the field of epigenetics, the study of changes in genetic expression that are not linked to alterations in DNA sequences. Some of these epigenetic changes can be passed on to offspring in ways that appear to violate Mendelian genetics. And although these new findings do not support Lamarck’s overall concept, they do raise the possibility that “epimutations,” as they are called, could play a role in evolution. “I don’t know of any evidence that Lamarck was even a little bit right, but this is possible,” says molecular geneticist Eric Selker of the University of Oregon, Eugene. “It is increasingly clear that epigenetic mechanisms play important, sometimes critical, roles in biology.”

      http://www.sciencemag.org/cgi/content/full/288/5463/38

      So perhaps Larmarck had it a bit right

      EDIT I forgot to add when I first posted this that Lamarck’s theory was generally accepted as wrong by the beginning of the twentieth century. The modern Science reference does not support Lamarcks general theory but just hints that it may in some special cases happen /EDIT

    • #20642
      protozoan
      Participant

      For those who are lazy to read the all the excellent link added by DevGrp, there is a main passage according to lamarckism:

      quote :

      a change in the environment causes changes in the needs of organisms living in that environment, which in turn causes changes in their behavior. Altered behavior leads to greater or lesser use of a given structure or organ; use would cause the structure to increase in size over several generations, whereas disuse would cause it to shrink or even disappear. This rule — that use or disuse causes structures to enlarge or shrink — Lamarck called the “First Law” in his book Philosophie zoologique. Lamarck’s “Second Law” stated that all such changes were heritable. The result of these laws was the continuous, gradual change of all organisms, as they became adapted to their environments; the physiological needs of organisms, created by their interactions with the environment, drive Lamarckian evolution

      .

      I think such a good example of “a use or disuse” is our brain. If we learn our brain increase its ability such as to solve problems or to keep remmembering a things etc. It is so evolved organ that it can evolve even during the lifetime of a one man. The question would be if those evolved abilities in a one man can inherit his offsprings or the offsprings must begin from total beggining to assume these abillities.

    • #20652
      mith
      Participant

      That’s very interesting.
      I noticed that ppl who wear glasses usually have children or parents who also wear glasses. But the trend seems discontinuous, I mean, most people have normal vision in the 1700’s. Could myopia be something like that?

    • #20682
      protozoan
      Participant

      Yes myopia could be the example of a disuse of an organ – eyes. Maybe we dont use our eyes like our ancestors did. But for me the better example could be our teeth. Somewhere i heard that our teeth has changed cause we now eat more processed food

      I clicked on a submit but i didnt wanted it, so i continue. Food is now softer than ever before. Cheving surface of our teeth is smaller than before.. We have bent teeth and many of young people must have brace. But why theres no people who have perfectly strong teeth adapt to chew a hard food like our ancestors had. Theres no natural selection to us, so if Darwin was right there should be milion types of teeth(cause theres no natural selection to prefer only the most favourable possibility). But not, the main trend is decreasing of chewing surface in all humanity.
      (in my lexicon i didnt find the word which could name the all set of teeth. So if i say teeth i mean the all set of teeth.)

      You can use the edit function~ mith

    • #20703
      2810712
      Participant

      I don’t know if anybody has mentioned this here, but how can we explain evolution of plants and similar organisms on the basis of lamarkism – do they say that god or some body or even light stetched the plants , so some of them could get stetched and thus got adapted. but wht about hormones ? Planthormones ,are , as per my knowledge , local, so , how would explain ? ? ?

      hrushikesh

    • #20782
      protozoan
      Participant

      Ok. Maybe these organisms which are passive are results of the natural selection. But maybe animals are more active organisms and so they could evolved mechanisms which could lead to lamarkism principle of inheriting acquired traits. I know it is only speculation, but maybe 😛

    • #20794
      thank.darwin
      Participant

      They would not acquire traits…this might be right or wrong… it’s up to you

    • #20799
      mith
      Participant

      Traits could be acquired through symbiosis.

    • #20924
      2810712
      Participant

      Symbiosis …???
      Symbiosis needs aquiring some traits, but symbiosis is not the mechanism to aquire any trait .

      There is some pt in what protozoan said.
      And protozoan, how would you explain the evolution of protozoa- first eukariotes,
      I think , as you say, there can be multiple mechanisms of evolution, but if you read genetics, old Lamarkism would get discarded readily. About new lamarkism, I agree that it can change genes to bbegin evolution , as all organisms would not try to stretch their body – atlast natural selection is required to eliminate the organisms with no hormonal and thus genetic changes , So, new lamarkism can be thought as a way to induce genetic change/s – inducing variation/s [ which is/ R raw material/s for natural selection ] in disered direction. So, its not random genetic change. It is different than the genetic change mechanisms provided by non-lamarkians , they provide the random change mechanism , so it will really require more time to carry out whole evolution on earth.
      The origin of life can not be explained by Lamark theory, but evolution of life after a specefic stage when organisms began to have their desires[ eg. the desire to stretch the neck or even a pseudopodium … ] and it could induce definite gene-change, can be explained, also, lamark theory provides non-random gene-change so it will take less time, so less people will question that whether life really originated on earth as earth is some few mil. yrs old. But it may be just one of the ways of inducing gene-change.
      Random gene change-mutation would also occur.

      hrushikesh

    • #20965
      protozoan
      Participant

      Random changes are for me somethin unuderstandable. Lets think about it. If any change occurs in the sequence of DNA, it causes a change in the sequence of amino acids of the protein, and if so change occur even in the active site of it, what will then happen? Such a protein will not work properly. What follow this? Disorder, disease. Genetic disease. Theres a lot of such a diseases. These changes are disordered. Also if such a change occurs in a cell in any place of the body it can never influence the offsprings only if it happened in the gametes. Diversity of the organisms or of the people is because of sexual process. My mother was fat, my father was thin, what the result would be possible? And will these result stand the natural selection? Thats the way i think darwinism could work. Not random changes in DNA everywhere it is possible. But the mixing the traits (DNA) through the sexual process and natural selection to the result of it.
      But i still wonder if Lamarckism theory would be right. I think it would be. People may think that certain thing is definitive true, but then they discover some detail and whole concept disintegrate. We still dont know all detaills so the doors of possibilities are still open.

      Also 2810712 what u told thats the way i think lamarckism could work.

    • #20978
      2810712
      Participant

      I think, I’m required to explain what random changes are, probably i’ve not explained it correctly in that post, sorry.

      @protozoan

      Some thing about random changes.
      Consider a polyfatous [ very faaat] boy, he wants to drink some drink. so he goes in kitchen and takes the ingredients of that drink, and then mixes them. Mixing is a change here. He only mixed those ingredients which were required, so his mixing [= change ] was not random, it occured in some definite direction. If this change had to be non-random he would have mixed every available ingredient. Same is the case with
      Lamarkism , in it, changes in DNA occur in definite direction, and in the mutatiions there is no any definite direction of changes,
      Thus, probably , DNA chnges due to lamark effect cannot give rise to entirely new thing.
      Thus, ex-lamark effects [ eg. mutation] are also required to explain evolution.

      hrushikesh

    • #21415
      protozoan
      Participant

      Ok, but i still dont believe in disordered changes in dna. These changes cannot have any perspective. I think theres evolved mechanisms which could evolve even in first procaryotes through wich dna is changing. Not disordered changes. Through so changes 90%(my raw guessing) of offsprings have no chance to live.

    • #21581
      Sereuetokage
      Participant

      I urge you all to access this site and learn the truth of Lamarck vs. Darwin:

      http://www.textbookleague.org/54marck.htm

      Spread the word so that none will suffer this ignorance any longer!

    • #21583
      mith
      Participant

      Oh I don’t know about the validity but I love how this site brings up objections to common text books(especially since I found my dreaded history book on the list).

    • #22035
      Beetle
      Participant

      The site is ok but what can guarantee us that their version is not just another side of the story? Except that you have personaly read the Lamarck`s works.

      The idea of inheriting parents traits is foolish. The animals do not desire to have longer neck. Especialy lower animals dont desire anything and plants cannot have so diffrent way of evolving since thay have the same genetical structure. The elongation of giraffs neck is product of natural selection. The animals with longer neck had a better chance of survival and they left more offspring that had longer necks too.

      How can any biologist today that knows basics of genetics even consider this idea? If parents can pass on their acquired traits than that would mean that new genetic material can be integradted in the dna. But not in the dna of somatic cells, eg. muscle in the body of a spotsman, but in the gamets wich have no relations with lifting weights. New dna can be inserted trough virus infection but you can hardly say that it was deliberatly done by the parent. The only other way in wich parents can stir the development of the offspring is by the citoplasmatic induction. The unevenly distribution of citoplasmatic componetnts in the ovum may determine the way of embryonal development. But again it is not the delibarete stiring.

      In regard of the elevating number of persons with glasses that can be explained by the higer control of eye sight in the 20th century than in the 18th. It is posibly though that since we have a organised society for a few thousends of years that selectiv pressure on poor sighted individuals has loosen up and that those poor sighted individuals are not excluded from the reproductive genetic pool of human populations so their number trough time could increased.

      There is one more problem with using the words like “desire” and “wanting” in the biology. These words automaticly implicate religion and/or some kind of higher, havenly premade plans for all beings. This can make conflict somewhere there isn`t one so it is best not to use them.

    • #23121
      jrmonfor
      Participant

      Although I rarely enjoy arguing for the side that makes absolutely no sense, there are actually some decent examples of “Lamarckism” that don’t initially seem so ridiculous (I’m looking at you, whoever it was that brought up the giraffe necks). But first off, Lamarck’s theories are wrong. He did not have the knowledge of genetics we now benefit from. It just so happens that some of the garbage in his theory is partly true…by pure coincidence.

      That said, I do believe that some acquired non-hereditary traits can be passed between generations. As an example let us examine the giant sloth. If it is in fact advantageous to be larger, this may eventually lead to the selection of sloths whose genetics code for a larger sloth. Over thousands of generations natural selection would favor these slarger sloths, and voila!…giant sloths. But one nice thing about growing giant is that it is controlled by hormones. Envoronmental factors can easily alter the production of growth hormones. Ergo, a regular sized proto-sloth (with regular sized sloth hereditary genes) can grow larger due to envoronmental factors. When our large proto-sloth is pregnant, it’s environmentally induced levels of growth hormone can act on the fetus, resulting in…another large sloth that still does not contain large-sloth genes.

      That was obviously a hypothetical example. How about a scientifically documented, practically common knowledge example. The immune system.

    • #23143
      mith
      Participant

      I hope there’s a part 2 to this :D. Plus I’m not sure if the mom’s growth hormones will affect the baby for the rest of its life.

    • #23356
      Beetle
      Participant
      quote mithrilhack:

      Plus I’m not sure if the mom’s growth hormones will affect the baby for the rest of its life.

      I agree with this. Maybe if the enviromental factors remain the same (favorable for giant growth) troughout the offspring life but in the moment the factors change even slightly everything would go back to normal beacause it`s not genaticaly determined.

      What did you mean by immune system? That the babies after birth have temporary imunnity gained from their mothers?

    • #23486
      jrmonfor
      Participant

      The great thing about growth hormone irregularities (if indeed there is a positive) is that they are not always required to act through the entirety of the life of an individual. In the hypothetical example I discussed earlier the hormones were elevated only in utero, and possibly during early developement (I’m not certain whether GH’s are lipid soluble enough to be transmitted through lactation). The point is that elevated exposure for that limited time can have a perminent effect, that’s how growth hormones work. When you went through puberty those oh so enjoyable growth-spurts were caused by temporary elevations in growth hormone levels. After puberty, when your hormone levels returned to their normal levels you didn’t shrink back to your childhood size.

      Back to sloth. Maybe the effect of the growth hormones won’t be so dramatic as to produce a giant adult, but what they will do is produce a larger than normal baby. If the environment of this offspring is not the same as the one it’s mother was exposed to, and there is no environmental influence on hormones, there is no reason this sloth would end up much larger than any normal sloth. And most importantly, all things being equal, the size found in it’s mother will not be passed in any way to the subsequent generation.

      This is in essence why nobody in their right mind should be arguing for Lamarckism. I only wanted to point out that by complete fluke Lamarck was partly right; that some traits can be passed without involving hereditary DNA. But the traits that may be passed through one generation do not enter into the hereditary blueprint of that generation. This is the key to true evolution. Learning to play piano and having the genetic coding for cystic fibrosis are two entirely seperate things.

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