Evolutionary science

[nadinbrzezinski]

Yep, been thinking about this over the last day or so... and yes even some of those obesity threads made me wonder

Ok... we KNOW the FTO gene is real... which means some folks will be MORE predisposed to obesity than others.

And depending on how many expressions of the damn gene how bad it can become. (Anecdotally there is a british family who does have an obesity problem from hell and it is genetic, yes they were mentioned in one of the very educational programs on the issue on TLC, will hunt for the link... and that is an extreme case)

So here is the question

We know obesity has ties to diabetes, in fact, two expressions of the FTO gene are directly linked with it. Why then have it> What is the Darwinian Advantage?

Go back oh even 200 years... let alone 10,000 years, when times of plenty were followed by famine, and famine was followed by plenty

Think about it, if you have a better ability to store fat, you will be ready to face famine better. In fact, until fairly recently, historically speaking, fat was a symbol of beauty in Western Cultures, starting with the Fertility goddesses of the neolithic, all the way to the 19th century

Thin as a rail, (or even better somewhat thin with airbrushed photos) is recent... and has all to do with not facing that many times of famine

Now if I am right, all them folks who have that gene will have an evolutionary advantage if we face a die out of the species. Not that does not mean you individually have a better time, but if we evolved to have this ability... it stands to reason that in a famine these folks will have an easier time making it through.

Food for though, and perhaps our standards of beauty will go back to the more traditional ones, over the least 10K years or so of history.

Oh and it goes to show that these genes are not adaptive in a constant time of plenty... which once again is rare in human history, as in a unique moment in our history

[HiFructosePronSyrup]

1. Why would it have to be an advantage?

It could just as easily be a disadvantage.

[nadinbrzezinski]

3. Because you are able to store that fat (energy) better in times of plenty

therefore make it through the lean times better

This directly leads to your ability to reproduce and pass this along

[HiFructosePronSyrup]

4. I'm asking what makes you think the gene is advantageous.

Not a hypothesis as to how it could be advantageous.

[nadinbrzezinski]

7. Exactly what I posted, that working hypothesis, is probably the explanation of

why it is there

[HiFructosePronSyrup]

8. Your hypothesis is based on a flimsy assumption...

that the gene is an advantage to begin with.

I'm asking you why you're making that assumption.

[nadinbrzezinski]

10. Very simple, the percentage of the population that has an expression of the gene

If it wasn't advantageous it would not be there, or would be a true genetic defect... as in rare

Here are the numbers

About 16 per cent, or one sixth, of Europeans are likely to have both copies of the variant, according to the study. And around half will have one or two.


http://www.medicalnewstoday.com/articles/67666.php

http://www.sciencemag.org/cgi/content/abstract/1141634v1

Have you ever taken a biology class?

If 16% of the population have two expressions, how many have one?

I'll let you go back into biology 101 on your own

[HiFructosePronSyrup]

15. Oh, lawd.

1. Lots and lots of people have plenty of genes which are of no advantage whatsoever. A high prevalence of a gene is not evidence that a particular gene is advantageous.

2. Obesity is correlated with the FTO gene. It is not necessarily the primary function of the gene. Meaning speculation is even more silly than usual.

3. You suggest two independent reasons for prevalence- advantage during famine, and sexual selection. Sexual selection is rarely advantageous.

4. I've taken biology 101, and am quite competent when it comes to genetics for amateurs. Have you taken graduate studies in the field of Grasping at Straws?

[nadinbrzezinski]

19. Never mind then... have a good day

after all I must bow at your wisdom

And 10K of history (at least) be damned

Or for that matter, genetics

I asked a valid question, I offered a hypothesis, and why it may work.

You, offered an attack

Good bye, the ignore list gets larger

[HiFructosePronSyrup]

20. ROFLMAO.

"And 10K of history (at least) be damned

Or for that matter, genetics"

You wanted to have a discussion on genetics, for fuck's sake. Talk about genetics.

"I asked a valid question, I offered a hypothesis, and why it may work. You, offered an attack"

You offered a flimsy hypothesis and I asked a valid question based on that hypothesis.

You responded by insulting my intelligence.

Maybe you shouldn't dish it out if you can't take it.

[Crunchy Frog]

22. She's right. If you ever take a class in evolutionary biology, genetics

or population genetics, you will learn why it is widely recognized among scientists that the prevalence of a genetic varient in a population is an indication of positive selective pressure. Biology 101 probably doesn't delve into the phenomenon sufficiently.

She's not talking out of her ass though. This is the scientific consensus.

[HiFructosePronSyrup]

25. Have YOU taken those courses, Crunchy?

Then please, explain the wide spread prevalence of many non-advantageous polymorphisms.

[Crunchy Frog]

34. Something can be generally non-advantageous

and still have some advantage in certain contexts such that there will be some level of selecion pressure in its favor. An example is the sickle cell trait.

If you are genuinely curious about this, it's possible to research it on your own. If you just want to argue about it, there's really not much point in people making any further attempts to explain it to you.

[HiFructosePronSyrup]

35. So... no?

"Something can be generally non-advantageous and still have some advantage in certain contexts such that there will be some level of selecion pressure in its favor. An example is the sickle cell trait."

Sickle cell has a clear heterozygous advantage.

I'm talking about all the polymorphisms with none.

[Crunchy Frog]

43. And how do you know that they have none?

Have you imagined all of the possible contexts in which they might occur, or have occured in evolutionary history?

[On the Road]

12. Since We're Talking Evolutionary Science,

if a gene survives in a large proportion of the population for any period of time, you have to assume there is a reason. The simplest explanation is that it is adaptive, no?

Whatever disadvantages obesity has, storage of energy for periods without food is not a negligible advantage in preindustrial societies.

[nadinbrzezinski]

14. It is only a disadvantage in a world where we have a constant plenty

exactly

Not endorsing going back to famine=plenty cycles, never mind post petroleum may just do that

[HiFructosePronSyrup]

18. "The simplest explanation is that it is adaptive, no?"

No.

[On the Road]

21. No?

Do you not accept the principles of evolution? It's almost tautological to say that survival of a gene is adaptive.

It is possible, for example, that the physical expression of the gene under discussion is nonadaptive, but that the gene has more powerful adaptive expressions. There are of course "accidents" if the population is small enough or if there is a cataclysm which can reduce the population to a few nonrepresentative individuals.

But generally speaking, survival of a gene equals adaptiveness.

[Eryemil]

40. Sorry to piss on your cornflakes OP but he/she is spot on.

[Taverner]

2. It does not have to have a Darwinian Advantage - it just needs to reproduce

So if two obese folks with diabetes have children, then the gene makes it onto the next gen

[nadinbrzezinski]

6. Yeah but the FTO gene is expressed in a fairly high percentage

http://www.medicalnewstoday.com/articles/67666.php

When you have one expression is may be adaptive, two not so really

One of those, one thing is a good thing, but too much, not really

Why diabetes has existed ever since

And from what I read, perhaps diabetics have two expressions of it

[Taverner]

13. How does it affect reproduction though?

Look - people can reproduce traits that are harmful - but the main point here is: do they reproduce?

[nadinbrzezinski]

16. For it to be present in the population in the numbers it does

people with it reproduce very well thank you

Half of the population has one expression of the gene in europe

Those are high numbers... which hardly makes this mal adaptive

[nadinbrzezinski]

17. For it to be present in the population in the numbers it does

people with it reproduce very well thank you

Half of the population has one expression of the gene in europe

Those are high numbers... which hardly makes this mal adaptive

[Rosa Luxemburg]

5. look at the Zucker rat which is genetically OBESE

http://www.rps.psu.edu/jan97/zucker.html

[Juche]

9. My understanding is diabetes may be due more to surviving famine

An explanation I have heard is that the insulin resistance seen in fatter people was useful during times of famine as it meant that glucose in the bloodstream was higher and it was shuttled to the organs that needed it the most. Low insulin resistance could result in glucose being absorbed wherever it found an insulin receptor whereas high resistance would lead to glucose being more likely to be absorbed by the internal organs and brains, which would help a person survive famine.

Another thing I've heard is that yes, obesity was attractive until about 1920 and a major reason it became ugly was that starting around 1920 poor people had enough wealth that they could become obese too. Before then only the aristocrats (with their access to endless food and the fact that they didn't need to perform manual labor) could get fat. Once poor people started getting fat it became ugly.

[nadinbrzezinski]

11. The gene is directly related... increasingly a chicken and egg problem

and indeed thin is a modern standard of beauty

[zipplewrath]

23. You're making alot of assumptions

1) It is an advantage. It could be a combination of dominant and not a discriminator

2) Any tendency towards obesity could lead to a greater chance to survive various famines. The predominate risk from famines was not a caloric starvation, but a vitamin deficiency. It leads to the spread and susceptibility to disease.

3) That being slender has no advantage. Current studies suggest otherwise. Extremely low calorie diets, and extremely low body mass have been found to be advantageous over the long term. There is an unfortunate "cliff" at which all the advantages are lost and it is suddenly hazardous. However, that cliff is well below even moderately thin folks weight. (A 6 foot tall man could healthily survive being 135-155).

4) That exercise plays no role in the advantage, or disadvantage of this gene. Really, it goes further than this and the question is the utility of the gene could be connected to the presence, or lack thereof of many other discriminators.

[nadinbrzezinski]

24. I place it in the same category, if I am right, with sickle cell

you have one expression you avoid malaria, two expressions, it can and will be deadly

So I'd say two expressions are deadly, since they also happen to be directly related to diabetes and other bad effects

Also genetic predisposition does not say that exercise is off, and being six pounds over the mean weight, is not crazy... we are not talking here extreme obesity

That said, the prevalence of the gene in the population tells me it has to have some evolutionary advantage, one that in an age of constant plenty... for god sakes we have a thankgiving meal every night (caloric intake and protein intake speaking) is not what this was designed to do

Why an otherwise adaptive gene... is going haywayre and explains why we are seeing this crazy increase in obesity world wide

Mind you... would be nuts to say that this is the ONLY explanation... medical origins are fine and dandy, but we also have plenty of social cues

See that feats we have every night? That is a social cue, learned from times of famine... eat when you can... and people are...

As to extremely low caloric diets and their effect in longevity, we have contradicting data, like everything else in science

Me... I take a more balanced aproach to it

We have protein every day, as hubby works physically... he needs that protein, but we don't have more than four to six oz, when we really splurge, and we watch what we eat.

but given the science I am willing to bet that my family has the FTO gene in one and two alleles, makes it harder that's all, and yes, we get to enjoy diabetes too, why I suspect the two

[AngryAmish]

26. Maybe preference for thinness is just fashionable

Rich people nowadays do not like to be fat. Thinness is a sign of wealth/high status (except if you are a methhead. then you are just nuts).

[dustbunnie]

27. 19th century women of affluence suffered from the vapors -

and had fainting couches. They often took to their beds, why? Because they were cinched in so tight, they couldn't breathe. It isn't exactly a phenomenon of nowadays as I doubt many women could claim the 18-inch waists these women did. The cherubic figures portrayed in earlier art were far from what we would call obese today.

The thirst for thinness today is a sign of affluence mainly because the rich run in circles that vacation on ski hills and socialize on tennis courts and golf courses. Wives who are supported by rich husbands are expected to go to the gym before luncheon appointments, and macher husbands do business on the racketball courts. Personal trainers and spa days are expenses that are de rigueur if you're going to play in the sandbox, along with the nanny, spiritual advisor/yoga instructor, deep tissue masseuse, and psychoanalyst.

[distantearlywarning]

30. This is true, but...

If you look at the pics of those women with 18" waists, they still look a lot "heavier" than the current standards of beauty. Their faces are rounder, they have plump little arms, they added bustles to their bums to make them bigger, and so forth. The only thin part about them is their highly corseted waists, which required torment from an early age to achieve.

I would argue that this is not an indicator that women of the Victorian time period were thinner than they are today, or that thinness was "in" at that point in time. Instead, I would argue that the fashions of the time were designed to maximize or "fake" a certain desirable waist-to-hip ratio, which involves at least the illusion of both a thinner waist and a larger ass (and often also pushed up the breasts to make them look larger) - the Elizabethans were into this look also. In a way, the fashions that required corsets make more sense from an evolutionary perspective than our current standards of beauty, which require no "curves".

[dustbunnie]

32. They look heavier because they had a higher fat to lean mass ratio -

but they were mostly tiny women. Go to any museum and take a walk through the costume pavilion. Any teeny modern woman could fit perectly into a suit of armor, but would have a really hard time squashing herself into the typical size dress worn in days of yore. Even the 1800s.

Somehow, in the 40s and 50s, women were allowed the more zaftig look, a la Marilyn Monroe, or Jayne Mansfied. It was short-lived.

I would argue that while the average runway model is a mere willowy twig, (clothes look better when walked down the aisle on human coat hangers as it allows the individual to dream of it on herself without the model's bodily projection) the reality today is that women are dieted down, have more lean to fat mass ratios - but make up for it by getting boob jobs and ass implants. The lips, I have no idea where that bee-stung look comes from, except perhaps its vintage from the twenties. There's no real difference between the silicone of today and the clothing faked-out hip-to-waist ratio of earlier days. We're still expected to have curves.

[distantearlywarning]

38. The bee stung look and "thinner vs. smaller"

Fuller lips are associated with youth i.e., fertility. The bee stung collagen look of today's starlets is a (rather pathetic and extreme) attempt to fake looking younger.

I agree with you that the women of yesterday were smaller overall (better nutrition has made us all bigger in the sense that we are taller and proportionately larger in every way, regardless of the whole fat thing) - but would argue that's not the same thing as "thinner". It's possible to be 2'3" with much smaller *everything* on the inside (bones etc) than a 5'10" woman, but still be much fatter proportionately than that 5'10" woman.

For instance, I can only wear my grandmother's engagement ring on my little finger, and she was a much fatter woman than I am (yes, there were fat Americans before 1980, hard as it is to believe). She was proportionately much smaller than I am so her hands were much tinier than mine. I've never been able to fit in vintage gloves or many dresses from the 50s, even though I have smaller hands than most of my contemporaries. And that was true even when I had a BMI of 18.5, back in high school.

This is true of men as well. I have an interest in medieval everything, so when I was in Paris two summers ago, I toured the armory there. Very few modern men would fit into the suits of armor worn by the average Elizabethan man, and it's not because we're fatter. And it was clear to me that some of those suits of armor were made for some rather plump Elizabethans (not enough fencing practice, I guess...maybe that's why they needed the armor!)

And you have to admit that those zaftig starlets of the 1950s were sexy! ;-)

They say Marilyn Monroe would be a 14 by today's standards. I know that's not true - it's just a difference in dress sizes. She'd probably be more like an 8. But nevertheless, take a gander at these two pics side by side and tell me they're not radically different in a normative sense:





The second photo, by the way, was located at a page entitled, "Keira Knightley is a fatty". :eyes:

Can you imagine what the tabloids might say about the Marilyn picture in 2009?

I have some biases here, because I've always been more of a Marilyn type than a Keira type. It's hard being a Marilyn in a Keira culture. I lost about 30 lbs last year, have 30 more to go, but even at a healthy BMI, I won't be able to wear the average dress off the rack - I'll have to tailor it in the bust first. I have a dreadful time finding pants that fit because I actually have an ass, which apparently isn't allowed any more. And the only women who look like me in my culture are in Playboy (not complaining about that, but it's a bit discouraging at times...)

Edited to add: looking at that picture of Keira - I bet she doesn't actually have a fertile hip-to-waist ratio, she barely has any curve to her waist and her hips are very narrow. If she ever wants to find a mate, I think she's going to need a corset and a bustle. :evilgrin:

[dustbunnie]

39. Heh. I wondered where the bee-stung lips thing came from.

We're basically saying the same thing. People were smaller, but had more adipose tissue.

I put on my grandmother's gloves, and my fingers throb from the pressure till I take them off, but she was smaller than I was. I love wandering any museum I go to, just to look at what people wore, rather than the art patrons paid for. It's a far more honest assessment of how people lived. Even though the clothes were worn by the rich.

Yes, I find Mar very sexy, but also find Keira sexy too. I probably look more like Keira, with more lean mass packed on, but still, smallish boobs etc. I'm quite straight, but I find the boobs of Mar sexy, and also the taut belly of Keira sexy too. I would kiss that stomach from here to oblivion if I were so inclined. The thing is, in our societal plan, every body part, in any size, is as sexy as you wish it to be. Depends on what you like, and what your partner likes. Hopefully, people find their matches, whatever they are. That's not evolutionary. It's our fad of the moment, even if it lasts 200 years. When people stop growing a small toe, that will be evolutionary history.

But, to tell you the truth, I've worked with males my entire life. Somehow, I always end up in all-male environments, and I can tell you, many, many males love the idea of a woman who is Marilyn. They like your body type. Very much. :)

Nobody likes the ideal of the runway model. Nor should they. Advertising is meant to display a product - a human with a vacant look, or a ravish me look (this is what you'll get if you buy the product), was never meant to tell people how much they should weigh or how they should look. We've just somehow morphed from what we like, to what advertising depicts.

[distantearlywarning]

28. Ding ding ding. We have a winner, folks!

Although it has been demonstrated in cross-cultural studies that certain indicators of fertility are universally favorable, such as a certain waist-to-hip ratio in women, it has never been demonstrated that thinness or plumpness (note: I did not say OBESE) are found desirable by all humans regardless of external environmental or social factors. (And yes, Virginia, it is very possible for a woman who would be considered "fat" by current US standards to have a favorable waist-to-hip ratio - I do, and I'm a size 14...)

It has however been demonstrated that weight preferences are directly linked to socio-economic factors in a particular society, such as famine or differences in typical occupations between rich and poor citizens. In particular, there is a correlation between economic hardship and preference for "fatter" mates (and "fat" also = high social status when most of the population is starving).

For example, one interesting (correlational) study I read a few years back involved matching the average weights and body types of Playboy centerfolds over the last 50 years to economic indicators, month by month. Although no Playboy centerfold was obese, and waist-to-hip ratios remained relatively constant, there was in fact a statistically significant positive correlation between weight/visual "heaviness" and economic downturns. Similarly, the thinnest centerfolds were found during times of plenty.

Just some food for thought (no pun intended)...

Personally, as a woman who never met the current fashionable "greyhound" standard for women even when I was a size 2 (short with D-cups doesn't work well when all the size 2 clothes are made for 6' models with no boobs or ass), I kind of welcome the advent of a recession/depression. The shittier the economy gets, the better I look! Bring on the "recession goggles"! :rofl:

[nadinbrzezinski]

36. Yep, this is relatively recent

1920 or so to be exact

And limited to the US and some of the west

The ideal of beauty in places that still see famine are women who have wide hips and weight on them

Like oh, art in the west all the way to the 1920s, starting with the Goddesses of fertility in the Neolithic?

[seabeyond]

29. problem with evolutionary science, so many "guesses" and stories told then stating fact

the big thing today in evolutionary science is cop out for lack of control adn they dont make sense, but it just allows us to do whatever we want with no control. it is bullshit and then people yell it is biology.

[distantearlywarning]

31. I wonder if you would be a believer

if evolutionary theory supported the viewpoints you already hold about what is a "good" body type to have?

Unfortunately science isn't made in man's image. And evolution will continue on with or without your support. But thanks for the commentary.

[seabeyond]

33. i dont think what is being spewed today will. i think much of it is already being dismissed

i am not talking about evolution theory vs creationism. there is truth in evoltion theory i believe, but i dont believe it is what we are presenting today.

the science is only as good as the scientist and with shit like this, agenda plays a factor

as far as body type... i really dont hold any viewpoint of "good". i am much more flexible in seeing how unique we are and the gentic factor involved not to mention the upbringing and lifestyles we live.

really distant, in the post i typed, there was so little to no information on what i believe and for you to draw any conclusion with such a huge and encompassing subject as evolution is exactly my point.

you really dont know what the fuck is my particular problem, where i see the contradiction, what i believe.... nada. you just conclude without info

[nadinbrzezinski]

37. So tell me, the FTO gene is a figment of researcher's imaginations?

SO is sickle cell I suppose?

Perhaps other less adaptive genes perhaps (Some blood diseases perhaps)

Reality is KNOWLEDGE IS POWER... and if you KNOW what is the state of the art, you can do something about it

Nobody is telling you, at least not me, well you have this fat gene, so seat down and do nothing...

That said, we do have some extreme examples where the standard line is wrong, exercise and diet do nothing for these folks (who in earlier times would have died well before reproduction most likely)

For most people this means that our present approach of starvation diets that generate famine conditions don't work... see that evolutionary theory...

Why the sports\diet industry is fighting this research... it is the economics of it.

That means we NEED TO CHANGE how we do business, that's all

You can still lose weight... in fact you should. That does not mean that your genetics play zero role in this.... and your chances (if you are of western origin) of having at least one expression of this gene are 50%... how's that for reality?

Use science to benefit YOU... and what we have been doing ain't working... insanity is to keep doing exactly what does not work...

SEE THAT IS THE BLOODY POINT and the point that the puritan brigade is fighting and will continue fighting, as well as the diet and exercise industries, that run in the billions

It is in their interest for you to keep resisting what is the state of the art research right now

Some data for you

Eating 1500 calories in a day is not enough. It is HOW you eat them. If you eat them in one or two large meals, you trigger the famine response. If you spread across the day... the body speeds up, as we are in a time of plenty.

That is but one example of what is changing

Hell, some experts have actually tried near ideal caloric intake diets spread across the day... with better results than the near starvation diets that have been standard over the last fifty years

This is where knowledge plays a role

Now it is your choice to keep doing what has had a 95% failure rate... or try to use the new knowledge to work with your body, not against it

Hell, counterintuitive, some of these really fat people are malnourished. You figure that out

[HiFructosePronSyrup]

41. The sports/diet industry is fighting the research?

Why, that's a theory about a conspiracy that I'd like to hear more of.

"Hell, counterintuitive, some of these really fat people are malnourished. You figure that out"

Uh, that's not particularly counterintuitive. A poorly balanced diet in junk food would explain it.

[Evoman]

42. I think your misunderstanding evolution a little bit.

Although its common for people to assume that every gene is advantageous, it is not true at all. Genes can be neutral or even disadvantageous, as long as they don't stop reproduction.

Your guesses as to how they might be advantageous are not bad suggestions, but they are still nevertheless guesses. Not everything has a Darwinian Advantage (tm).