To wonder what repectable scientific notions of today....

[RubyGates]

will be laughed at in a hundred year's time?

Things that were believed by scientists in the past:
www.toptenz.net/top-10-most-famous-scientific-theories-that-turned-out-to-be-wrong.php

For the first time ever I may flounce off a thread - Are we really arguing about this? Fine - I will go and read my first year genetics textbook again, it has been a very long time since I did anything to do with population genetics, although I was actually simplifying things for a non-academic post.

LeBFG - I don't think enough is known about epigenetics yet, and I certainly don't know enough about it yet to claim to understand its mechanism, but I was certainly not under the impression that it supports Lemarckism, just indicates that he might not have been such a numpty after all.

What? Are you making that assertions based on your extensive reading of the wikipedia FFS? For your information I have a degree in genetics, a masters degree in molecular biology and a PhD in botanical taxonomy. I work specifically in the relatedness of plant species based on their genotypic characteristics rather than their phenotypic characteristics. However, I don't teach first year population dynamics which is all you've mentioned.

And for that matter all you have done is say that I'm wrong. You have provided no argument or knowledge of your own. Nor have you countered the specific explanation I gave you of where I feel your understanding falls down regarding popluation evolution vs species evolution.

Epigenetics isn't new. Evolutionary epigenetics is a much more recent development, which doesn't (imho) really relate in real terms to Lamarckism.

If I were to put my money on any specific aspects of science, I'd go for string theory and man made climate change. That said, I think the biggest change of the last few hundred years is the disinclination of scientists to claim to know everything, or to dismiss alternatives. Future scientists are unlikely to laugh at String theory, even if it is a laughable idea, because it's not widely accepted as fact.

I do think though, that things like radiotherapy, chemotherapy and other drugs with significant QoL reducing side effects will be considered to be almost barbaric, as novel treatments massively improve prognosis and reduce toxicity...

Don't flounce. I'm interested in this subject, trying to be clear.

But kindly do not accuse me of "mocking" you for something I didn't even know you had. That's outrageous. I was scratching my head thinking "Who's Le Mark?" - that's all. I should have guessed, of course, but I was trying to remember the name of the monk with the pea pods. I just had an "Oooooooh, right" moment. No mocking at all.

Anyway - there's no such thing as "individual evolution". Individuals don't evolve - there may be developmental changes or effects of the environment, but these aren't caused genetically. Evolution is defined as changes in a population over time.

So, you see my problem with what you're saying? From start to finish it makes no sense.

And I do think you are confusing natural selection with the various processes of gene variation.

Just read the link:

It was only with the adoption of the scientific method that many of the classical theories like spontaneous generation began to be tested. Once they were, they quickly crumbled. For example, famed scientist Louis Pasteur showed that maggots would not appear on meat kept in a sealed container, and the invention of the microscope helped to show that these same insects were formed not by spontaneous generation but by airborne microorganisms.

Since when are insects born of microorganisms? Last time I checked, insects arise from eggs of their parental insects, which are not generally considered to be microorganisms

No expert AT ALL here on evolution (my degree was a long time ago).

But if environmental changes are found to lead to epigenetic modifications of the genome, which affect phenotype, then isn't this effectively environment changes via genetic modification (just not mutation). What I mean is, isn't it effectively or functionally genetic modification, just not in the way that we're used to thinking about it happening (ie only mutations).

Even more interesting if the evidence firms up on the possibility of inheritance of epigenetic modifications.

I know there are a lot if ifs here!

No it is my turn to say you are wrong. I'm afraid the first thing you learn in a evolutionary genetics lesson is that change over time can be looked at on three different levels:
Change within an individual organism within its lift time - which is still change over time and therefore IS evolution, but according to Darwinsim cannot be passed on, Lemarckism can be passed on, and this is being questioned by epigenetics.
population dynamics - changes within a population of a species over time
species evolution - changes within a species over time
What you are talking about will depend on which of the levels you are looking at. All thread I've been talking about the third level, you have been talking about the second.

The monk is called Gregor Mendal. And I know how to spell that one

Gregor Mendal???

Who's that?

So close, Danceswithwool... that would be Gregor Mendel

Gregor Mendel ...as obviously as Le Marc == Lamarck.

Ups, sorry, you are dyslexic.

Although who would have guessed, until you said it, in a defensive tone? No need for that.

Even I was stumped about who Le Marc was.

Ellie - there are three types of evolution - individual evolution, which is change in an individual in their lifetime and not relevant to this discussion There's no such thing as individual evolution, as I've already said.

population evolution - the change within a specific population over time - this is where genetic drift and gene flow are mechanism Yes....

and then there is species evolution - change in whole species over time. The only time population evolution effects species evolution is if that population is the only population of that species or if it causes speciation, which is rare This is not a different type of evolution! It's a further along step in the process, which may or may not happen.

We have genetic variation, yes? This is where evolution ("change over time") begins. Either natural selection, genetic drift or some other mechanism then gets to work to bring about change.

You said that scientists have been claiming that NS is the only mechanism. They haven't - genetic drift (for example) IS such a mechanism.

You then started going on about epigenetics & mutations. This has nothing to do with natural selection - it's a stage before it. So I'm not sure what it has to do with your claim about scientists dismissing all mechanisms except NS, when epigenetics is all about changes in the gene.

I have addressed your points. See?

And, frankly, the only people I can see talking about "individual evolution" anywhere online are, er, creationists.

How on earth do some of you cope with interpreting Autocorrect if you can't figure that one out?

No, I wouldn't have guessed Dances had dyslexia either TBF.

How about get back to the rather interesting OP?

Gregor Mendel. Aha. Yes, him. Was also thinking of "LeMaitre" - but he's the BB chap.

But if environmental changes are found to lead to epigenetic modifications of the genome, which affect phenotype, then isn't this effectively environment changes via genetic modification (just not mutation). What I mean is, isn't it effectively or functionally genetic modification, just not in the way that we're used to thinking about it happening (ie only mutations).

A lot is known about epigenetics. The speculative bit is its role in evolution. The problem is epigenetic effects only persist over a few generations. Adaptations require multiple permanent modifications in gene function.

Really Le Mark vs Lamarck stumped you all??? so le-mar-k versus la-mar-k? I'm sorry if you felt I over reacted but it never occurred to me that you weren't mocking my spelling but unable decipher the word.

Sorry Ellie, but short of scanning a University text book for you I don't know what else to say about individual evolution - it is a concept. There are three levels of evolution, it is the first one. I didn't make it up.

Please find me one example of long-term species evolution over the last 100 000 years that is accredited, large scale, to anything other than natural selection. All the other mechanisms are responsible for changes in populations. These may go on, in the case of extreme island biogeography, to give rise to subspecies at best, but in normal species it gives rise to variation within the species. This variation is them subject to natural selection. It is impossible, according to Neo-Darwinian evolution for anything to evolve without selection pressure.

Just reading through the last bit, I think some confusion is arising over genetic variation and adaptation. When specialists and laypeople talk about evolution they are talking about adaptive changes not just changes per se. This is what Darwin talked about and what we mean by Darwinian evolution.

If epigenetics (aka lamarckism) has a role in adaptive evolution, it's so very minor that we can't really talk about Darwin looking foolish. I don't think we'll see this change over the next 100 years.

As good old Patrick Moore is quoted upthread, we're just filling in gaps.

Thanks lebfg. I didn't have a clue about whether epi modifications could be inherited and if so how long the effects could last, so that's helpful.

So am I right, though, in thinking that environmental things that change phenotype via epigenetic modifications could be considered as genetic modifications in a way, just not of the genetic sequence itself?

Ps I got Le Mark ;)

Oooer! Serves me right for going to bed and then leaving the house!

I have to admit that I quite like the idea of the "ether" simply because it fills in the gaps in the universe in a way that other theories/hypotheses don't. I know it's been disproved, but I do think there's a missing link in our thinking about the universe that hasn't been filled by the "discovery" of the Higgs boson.

I also have to admit that OH's Great Grandfather was Oliver Lodge and OH is a physisist so we have quite lively scientific conversations over the post-prandial port.

Interesting musings going on! Thank You.

Yes sorry Ruby we got a bit carried away on your fred . Still its better than no-one answering I spose.

As soon as I said "Le Mark" out loud, I got it, Dances. I think my brain got stuck trying to turn it into LeMaitre and wondering if he was the pea pod monk (I know he's not, btw).

Well, much as I would dearly love to, no I can't give you any such example - waaaaaaaaaaaaay over my head. If such an example exists, it's probably Googleable and I might find it, but that's not me answering you, that's getting someone else to. And I hate people who do that, so I'm not going to go down that route.

The only references I can find for "individual evolution" is either creationism crap, or scientists saying: "This is a misconception, individuals don't evolve". And given that, as I've said, evolution is defined as change in a population over time, I fail to see how that can happen in an individual.

Doesn't adaptation come from genetic variation, LeBef? Isn't variation where it all begins - pre Darwinian natural selection?*

*In case that came out wrong, not a challenge.....a genuine question as I'd like to understand more.

I'm happy you got carried away!

As always in arguments this comes down to complete semantics.

The basic definition of evolution is change over time. Used in that context, an individual can evolve, as can anything, from the music career of Pearl Jam to a thread on mumsnet. If you are only defining evolution as a change in a population over time, then clearly you are only looking at a population. However this is quite a narrow definition, as long term biological evolution operates outside of populations. You cannot talk about human evolution for example then, as it does not happen in a population, it happens in numerous species over long periods of time.

I think LeBef is correct - When I talk about long term evolution I am talking about adaptation - and even Wiki says that that is brought about by natural selection. It does not mention anything else. More semantics.

I am at peace now.

EllieArroway Yes, adaptations arise from genetic variation. Adaptations that persist have to be inherited somehow. But the vast majority of genetic variation isn't adaptive. So the two are related but distinct.

I think I follow your reasoning Dances (glad you're at peace btw) but I have to (pendantically) point out that adaptative evolution has to happen within populations. Only (usually) over a great number of generations do we see the effects.

Binkybix epigenetic mutations can easily be confused with genetic modifications because they are heritable over a few generations. If epigenetic mutations caused permenant, heritable changes then they would be effectively the same as genetic ones I suppose, yes.