Lamarckianism and genetics

[Deathby]

I remember watching a short documentary on this guy who believed in Lamarcianism evolution still and was out to prove it scientifically. He had quite a bit of proof that it worked in immune systems as well.

 

Given the complexity of living organisms, do you think that it would be feasibly possible for there to be a genetic way of explaining Lamarcianism (not necessarily in humans)?

 

Proteins are made of amino acids which also compose DNA. In stretching its neck, hence building up muscles, could the excess production of proteins foment a change in the DNA structure by mutation that could possibly be transferred at a later stage to the gamete cells? This is all done without much specific knowledge of precisely how new tissue is formed.

 

I mean if there was it would be a great boost to the punctuated model of evolution.

[Daymare17]

"I mean if there was it would be a great boost to the punctuated model of evolution."

 

Why would this be so?

[Sayonara]

It's not very likely. It's a bit like hoping some blueprints will change because you added extra bricks to the building.

[Deathby]

"I mean if there was it would be a great boost to the punctuated model of evolution."

 

Why would this be so?

 

Well if animals could utilise Lamarckian evolution in addition to Darwinian evolution they could react to changes so much quicker. Say distances between copses of trees grew greater as praries expanded. A zebra with stronger legs from all the walking transferring those legs to its offspring would allow it to adapt to the prarie lifestyle much quicker than if it had to wait for survival of the fittest over several generations.

 

And its not just wishful thinking, this guy has experimental data that suggests that immunity to certain diseases can be transferred to offspring.

[Skye]

It'd really help if you find a link about the guy.

[Sayonara]

And its not just wishful thinking, this guy has experimental data that suggests that immunity to certain diseases can be transferred to offspring.

That's not really news, unless the diseases are genetic conditions as opposed to pathogenic infections.

[chadn]

And its not just wishful thinking, this guy has experimental data that suggests that immunity to certain diseases can be transferred to offspring.

 

Ummmm, DUH!

 

In mammals the young are directly connected to the mother. So as the baby develops it comes into contact with these immunities and develops its own.

 

What species formed the basis for this guy's study?

[Sayonara]

I think my post was a bit more diplomatic.

[chadn]

I think my post was a bit more diplomatic.

 

I was never good at diplomacy

[Sayonara]

I'm often frightful at it on here, which is why that one stood out

[ecoli]

Larmarck's theory would say that if a mother dyed her hair blonde, then her children would have blonde hair. I don't trust Lamarck's theory.

[fuhrerkeebs]

Well if animals could utilise Lamarckian evolution in addition to Darwinian evolution they could react to changes so much quicker. Say distances between copses of trees grew greater as praries expanded. A zebra with stronger legs from all the walking transferring those legs to its offspring would allow it to adapt to the prarie lifestyle much quicker than if it had to wait for survival of the fittest over several generations.

 

But that's not quite the idea behind punctuated equilibrium. Punctuated equilibrium is sort of like natural selection at the species level, and what happens is a very long period of very small genetic variation, and then a period of very great change. You've described it as more of continual period of great change.

[Deathby]

Erm no what I meant is that the period of great change you just mentioned can be explained better by lamarckism than by evolution. What I meant was that a cataclysmic change in environment which provoked a stress on parts of an organism which would be transferred to the offspring hence adaptation to that change would occur faster than via survival of the fittest since changes would begin occuring within one generation rather than several.

 

Whilst I don't really believe that Lamarckianism occurs, I just like discussing implications like this since I find it incredibly interesting (despite the fact it is wishful thinking). I never really liked the science textbook way of explaining away Lamarckianism. Dying your hair blonde wouldn't affect the body itself in any way would it? I think cutting off mice's tails was a much better experiment, since lack of use of the tail would theoretically shorten the tail due to atrophy. I obviously can't find a way around this since I don't have access to a laboratory and lots of mice to disprove or prove his theory.

 

 

In reply to your question I believe he used mice. My internet research skills are quite bad, but I'll have a stab at finding an article on it. And if the offspring can be given immunogens by the mother, then why not other hormones? If the mother was producing excess hormones that direct proteins to build stronger muscles (I don't know any of the specifics about how this happens as I've said) then the hormones which float around in blood could be transferred to the offspring just as easily as immunogens.

[Aardvark]

I think cutting off mice's tails was a much better experiment' date=' since lack of use of the tail would theoretically shorten the tail due to atrophy. I obviously can't find a way around this since I don't have access to a laboratory and lots of mice to disprove or prove his theory.

[/quote']

 

A better example is Jews.

 

Jews have been circumised for thousands of years, and yet every Jewish boy is still born with a foreskin.

 

As for Lamarkism providing faster and better evolution then standard evolution, if aquired traits are passed on, then negative traits such as injures and losses of bodiy parts would be passed on. Your Father losses an eye, according to Lamarkism, you will then be born with only one eye. Hardly an improvement.

[Sayonara]

Erm no what I meant is that the period of great change you just mentioned can be explained better by lamarckism than by evolution. What I meant was that a cataclysmic[/b'] change in environment which provoked a stress on parts of an organism which would be transferred to the offspring hence adaptation to that change would occur faster than via survival of the fittest since changes would begin occuring within one generation rather than several.

I call that natural selection.

 

[edit] Assuming of course that it's not the "damage" that is passed on, but related adaptations.

[chadn]

In reply to your question I believe he used mice. My internet research skills are quite bad, but I'll have a stab at finding an article on it. And if the offspring can be given immunogens by the mother, then why not other hormones? If the mother was producing excess hormones that direct proteins to build stronger muscles (I don't know any of the specifics about how this happens as I've said) then the hormones which float around in blood could be transferred to the offspring just as easily as immunogens.

 

The problem is that this is not evolution. Just because the baby comes in contact with immunities from its mother and develops its own doesnt mean that the genetics are changed in any way. And unless the genetics are changed evolution is not going to occur.

 

Its no different then say my getting a small pox vaccine, I come into contact with the stuff, build immunities, but it doesnt get passed on.

[ecoli]

A better example is Jews.

 

Jews have been circumised for thousands of years' date=' and yet every Jewish boy is still born with a foreskin.

 

As for Lamarkism providing faster and better evolution then standard evolution, if aquired traits are passed on, then negative traits such as injures and losses of bodiy parts would be passed on. Your Father losses an eye, according to Lamarkism, you will then be born with only one eye. Hardly an improvement.[/quote']

 

 

Exactly my point, thank you Aardark

[Xavier]

In reply to your question I believe he used mice. My internet research skills are quite bad' date=' but I'll have a stab at finding an article on it. And if the offspring can be given immunogens by the mother, then why not other hormones? If the mother was producing excess hormones that direct proteins to build stronger muscles (I don't know any of the specifics about how this happens as I've said) then the hormones which float around in blood could be transferred to the offspring just as easily as immunogens.[/quote']

 

The problem is that this is not evolution. Just because the baby comes in contact with immunities from its mother and develops its own doesnt mean that the genetics are changed in any way. And unless the genetics are changed evolution is not going to occur.

 

Its no different then say my getting a small pox vaccine, I come into contact with the stuff, build immunities, but it doesnt get passed on.

 

A newborn has a newly minted immune system but lacks templates of the epitopes of potential invaders. Its mother donates an immunogenic profile of templates in the form of a collection of B-lymphocytes that she has received from her mother and added to during her lifetime. Should that baby be afflicted during its first weeks its survival is materially affected by the whether the immune profile that was passed to it includes a suitable template that can be used to manufacture a targetted immune response in days instead of weeks.

 

Evolution is a process, an algorithm that logically must proceed if three conditions are met, regardless of the medium (be it genes, memes, fragments of code in a computer, patterns of crystal formation in a snowflake etc.) These three conditions are, roughly:

1) There is an entity that can replicate itself more than once.(Facility)

2) Some property of the replicator can differentially affect the frequency with which it can replicate. (Fecundity)

3) The entity replicates itself with great, though not perfect precision (Fidelity)

 

Applying these conditions to the previous narrative, condition (1) represents the immune profile as the replicator, since the profile existing in the mother is reproduced in each of her offspring. Condition (2) is clearly met but condition (3) is arguably problematical. The question is: Does the B-lymphocyte library that the baby acquires remain in a recognisable form into adulthood?

Certainly, some immunities stay with a person for life (eg. chickenpox, mumps) whilst some vaccinations require regular booster shots (eg tetanus) and whilst very large, the immune profile must lose some candidates as others are gained or it would become impossibly large. Is the replication too imprecise to have an appreciable evolutionary effect without being overwhelmed by the more orderly instructions of the genes?

I would suggest that genetic evolution would select against anything that would disrupt this Lamarckian trait as the generation frequency of mammals compares unfavourably with the speciation frequency of bacteria. Thus babies would be in acute danger during their first weeks from bacteria that its genes had never heard of, making for a very strong genetic evolutionary pressure in favour of not buggering with the system.

It seems possible that the mouse immunogens mentioned earlier are a result of just such a process. The whole process may be difficult to detect precisely because it is so effective; whole phalanxes of hostile micro-organisms are perhaps kept down so effectively by this mechanism that we have never found them and hence we don't know even that there may be something out there to look for.

[aguy2]

Evolution is a process that logically must proceed if three conditions are met' date=' roughly:

1) (Facility)

2) (Fecundity)

3) (Fidelity)

[/quote']

 

Thank you Xavier. 'Facility, fecundity, fidelity' has a nice 'ring' to it; like something from the French revolution. I didn't 'butcher' your quote by condensing too much, did I?

 

aguy2