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

[EllieArroway]

Glad you're at peace - but no, it's not semantics, I'm afraid.

Yes "evolution" has many applications, like lots of words do. But we were quite clearly talking about biological evolution, and in that context, no, there's no such thing as "individual evolution". Sorry.

There are changes in populations which, given enough time, may result in speciation. And speciation is a stage in a very, very long process that includes the input of other mechanisms along the way.

I have a feeling that you're making the micro vs macro argument, just wording it differently.

But any way.......:)

[DancesWithWoolEnPointe]

It is semantics - I have not said anything factually incorrect - we are coming at this discussion from different places.

If all we are arguing now is that my introductory lesson in evolutionary genetics started with my professor saying that evolution (i.e. change over time) happens on three different levels - individual, population and species. Individuals have to change to change populations. Populations have to change to change species. Here is a link to my first year genetics textbook on line. Have fun. linky

As to what you actually challenged me on originally, which is me saying evolution is currently thought to be brought about by natural selection versus numerous other mechanism, we have established that I as referring to adaptation and that long term change in species, which is not the same as populations, is brought about by natural selection only.

Clear not at peace anymore.

[DancesWithWoolEnPointe]

I am going to flounce off now - I can only discuss the same thing over and over again so many times. It has been, erm, interesting. But at least we were bickering about science for once, makes a difference from bickering about benefits and breast feeding.

[alcibiades]

I think this thread, as well as others in the recent past, shows that there are some of us who have science questions, and there are people who have various levels of knowledge and expertise and are willing to share that. Although I do like the idea of having a Science/Nature area on the board, (as discussed here: //www.mumsnet.com/Talk/site_stuff/1580675-Science-Nature-Club-Topic-pretty-please, I guess one of the consequences would be that discussions wouldn't be as visible there as in Chat.

Something that does intrigue me is the interaction between genes and the environment in unusual circumstances, such as the Dutch famine of 1944 and how that affected subsequent generations. And then possibly the longer-term effects on the current descendants of those enslaved Africans who survived the privations of the slave ships and the conditions of slavery because they were so efficient at conserving calories and salt and fluids - which might be an explanation for higher levels of, e.g., hypertension in those populations as compared with others.

But, to hijack the thread even more (sorry, OP), what I'd like to see is the junking of the media's version of "scientific notions". Apparently, there's a gene for this, and a gene for that, when, for goodness' sake, it's not that easy even to explain eye colour.

[Binkybix]

bfg have I misunderstood what an epigenetic modification is? You described it as a mutation, but I thought that a mutation was a change in a base pair or a structural chromosomal mutation, but an epigenetic modification was something like methylation on a histone (so different to the first two).

So are these epi modifications also referred to as mutations? Not being argumentive at all - just like to understand things properly!

[Lueji]

Dances,
The three levels are of selection, not evolution, which is different.
Gene, individual and population.
While populations evolve, it's controversial if they are units of selection.
Individuals don't evolve, but they are the most basic and intuitive units of selection, because it's individuals that reproduce better or worse.

Genes and genomes do evolve, and alleles can be selected.

Natural selection should never be used interchangeably with evolution.

BTW it was not lemark versus lamarck. It was Le Marc. And frankly the frenchman's proposition has very little to do with epigenetics. Plus you didn't even mention epigenetics in that post. Just alternatives to natural selection.
Just because you are dyslexic you can't expect that other people have to understand what you write. And act smug that they didn't.
We usually expect some precision in writing.

[Lueji]

Binky
Epigenetic modifications are methylation of nucleotides in DNA.
This means that the particular stretch with methylation is not expressed (not active).
Say, you had an allele for blue eyes and one for brown eyes, normally you'd expect to have brown eyes. But if the brown allele is inactive, you'll have blue eyes.
One of the X chromosomes is usually inactive, for example.

But methylation could be at regulatory regions, thus affecting more complex traits.

Methylation patterns can be transmitted from parents to offspring, so they act like mutations, but are not really, as they are not long term.

It's a fascinating new area.

[DancesWithWoolEnPointe]

So I'm still being castigated for that, yet when I was accused of lying about my academic credentials not one person thought that was harsh? I found the tone of the correction of the spelling mistake harsh and belittling, implying that I did not know who I was talking about. I responded in anger. I have apologised. I was not smug, I was genuinely surprised. As am I that you would pronounce le mark and le marc differently?

I did not interchange natural selection and evolution. Nor did I confuse the three levels of selection with 3 basic types of evolution. I'm not an idiot. Individuals change over time - it is a fact. Whether you chose to discuss that fact in a genetics lesson seems to come down to by whom or where you were education on this topic or whether you are getting your facts off the internet

I had moved one, thanks for winding me back up again . Have a lovely evening .

[Binkybix]

Thanks luegi. Have just finished a popular science book on it - really interesting. It also spoke about a possible role for non-coding mRNA. Things have moved on since my degree, where I did some evolution and some molecular genetics courses.

Unfortunately I only tend to read when I go to bed so often fall asleep and forget some bits!

[degutastic]

Which book, Binky?

[Binkybix]

It's called 'The epigenetics revolution' by Nessa someone. Was good and seemed balanced in terms of what conclusions could be drawn from urgent evidence. I need to read it again really, due to falling asleep whilst reading in bed so missing some of he big picture.

[Binkybix]

• not urgent, current!

[degutastic]

Thanks, I'll look out for it, sounds fun

[Avuncular]

Natural selection should never be used interchangeably with evolution

Yay! Result!

Re-joing thread .....

[Avuncular]

Off-thread, but one of the most thrilling things about this thread for me is that there is still an (albeit small, perhaps) cohort of the UK population who can actually spell, construct sentences and string difficult ideas together sensibly.

Thinks ..... can the same be said of most aspiring science students or job applicants today?

(Not patronising but despairing .....)

[degutastic]

can the same be said of most aspiring science students or job applicants today?

Not in my experience. Language skills seem to be very lacking at present.

[Lueji]

Not being dyslexic and being very visual, for me Le Marc and Lamarck are very different. It's not really surprising. Why should I be supposed to figure out they were the "same"?
Besides, I pronounce the a in La-marck differently than I do the e in Le.

And yes, I'm afraid that I would initially wonder about credentials (I didn't question them, BTW) from someone who can't spell Lamarck or Mendel. A simple explanation would have sufficed.


And although individuals change over time, you can't really say they evolve, in the sense of evolution. (there may be exceptions, but not as a rule. Unless you count a lineage of single cell organisms as one individual, perhaps.)

And I don't need to copy things off the internet, thank you very much, except for the fact that most articles I read are obtained in pdf form. :)

[DancesWithWoolEnPointe]

oh look, someone spectacularly missed my point again. On this thread? Who'd have thought?

[LeBFG]

Apparently, there's a gene for this, and a gene for that, when, for goodness' sake, it's not that easy even to explain eye colour.

Excellent point.

Epigenetic mutations/modifications generally are methylation events - but not always. It includes everything but DNA mutations - this can include histone changes, prions (think BSE) and RNA molecules.

Anyway, anyway, I think the epigenetics revolution book over-eggs the Darwin-trashing....I found this for a read for anyone interested. We're just not going to see an end of evolutionary theory as we know it in a 100 years time .

[EllieArroway]

Dances Morning.

Just for clarity - you initially said that the science of the future would disprove the notion that evolution was all about natural selection with no other mechanisms given credence.

On the face of it, this is an incorrect statement. No evolutionary biologist that I have ever read has suggested that it's all about NS. They do talk about other mechanisms, although I tend to speed read through those bits 'cos I don't really understand them. I'm way more interested in NS because it's such a beautiful piece of logic that anyone can understand.

It may be that you didn't really mean that, as such, you were talking on a deeper level, but the language you used was incorrect which made the statement incorrect.

When challenged (by more people than just me) you started going on about epigenetics which has nothing whatsoever to do with whether or not evolution is driven solely by NS or not, so had no real relevance. And then you proceeded to tell me that there are three "types" of evolution, including "individual". There aren't - even a lay person like me knows that.

So, if you're offended by me being a bit about your credentials, bear in mind that I was basing that on the seemingly incorrect statements that you were making. We only have words on a screen to judge each other on, remember. You need to be really, really clear in your language when talking to a lay person like me - I didn't spend years at university learning this stuff, so nuances are lost on me.

But you are totally right - bickering about science is a good thing. I have learnt loads on this thread & it's a subject I really, really want to understand.

And LeBef & Lueji are my new heroes

So, I'm waving my white flag, Dances & saying thank you for a really fascinating conversation :)

[LeBFG]

I think the lamarkism vs darwinism 'debate' is a bit populist atm and was where Dances was coming from in her first post. Lamark and Darwin were essentially saying similar things - the big exception being that Lamark said modifications to our bodies during our lifetimes could be inherited and over long periods adaptations would arise (neo-Darwinists centre on the role of mutations in the sperm/egg cells). It turns out we can inherit life time modifications sometimes (epigenetics) but their role in evolution is extremely debatable because there is little evidence they persist over many generations.

[DancesWithWoolEnPointe]

Morning to you too Ellie

While I predictably disagree with your synopsis of the conversation and would summerise it in a completely difference way, I too tire of this and wave the white flag.

What I will agree with you on the tone of my original post. I certainly did not realise I would be getting myself into an argument a debate on the details of microevolution when I made the post, I thought I was engaging in a flippant thread. If I had intended to engage in a full scale scientific discussion with experts I'd have been wearing my scientific hat, using my most accurate scientific vocab and being very specific. As I was I was "dumbing" things down for a lay conversation and well outside of my field of expertise I also probably wouldn't have posted anything in hind sight

Have a nice day science nerds

[Gracelo]

I can't see how epigenetics means the end to natural selection either. I find epigenetics exciting and I am looking forward to any new findings in that field but for me it does not threaten ns. I read a review by Brian Appleyard in the Sunday Times of that book a while ago and also thought that the book (and the review) were over-egging epigenetics in respect to evolution.
For single cell organisms (mentioned earlier in the thread) the situation is different, at least for Prokaryotes which are my area of expertise, not sure about eukaryotic single cell organisms. Individual generations are hard to define and the entire concept of species is a little arbitrary.

[LeBFG]

When I first posted on evolution (think it was a god thread) I tried dumbing down a bit and was rapidly picked up too Dances. MNers are an astute lot - never underestimate your reader!