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Lamarckism still here

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Lamarckism still here

Postby protozoan » Fri Mar 18, 2005 3:06 pm

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?
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Postby Chris4 » Fri Mar 18, 2005 3:19 pm

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.
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Postby DevGrp » Fri Mar 18, 2005 3:52 pm

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

"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


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
Last edited by DevGrp on Fri Mar 18, 2005 5:01 pm, edited 1 time in total.
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Postby protozoan » Fri Mar 18, 2005 4:43 pm

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

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.
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Postby mith » Fri Mar 18, 2005 8:24 pm

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?
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Postby protozoan » Sat Mar 19, 2005 10:24 pm

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
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see this

Postby 2810712 » Mon Mar 21, 2005 9:58 am

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 ? ? ?

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Postby protozoan » Thu Mar 24, 2005 7:42 pm

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 :P
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Postby thank.darwin » Fri Mar 25, 2005 12:05 am

They would not acquire traits...this might be right or wrong... it's up to you
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
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Postby mith » Fri Mar 25, 2005 2:05 am

Traits could be acquired through symbiosis.
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there has to be

Postby 2810712 » Tue Mar 29, 2005 4:55 am

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.


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Postby protozoan » Wed Mar 30, 2005 8:22 pm

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.
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