Evolutionary advantage of X?

Dave!

Hey folks,

Thought it might be an interesting and useful idea to have a thread to speculate on and suggest explanations for particular traits or characteristics or anatomy.

For example, one might suggest that eyebrows on humans keep sweat from the eyes, so when fleeing from a predator or enemy, your vision is not adversely affected by your perspiration.

One that has been troubling me lately is laughter. What's the advantage of it? It's absolutely ubiquitous and has been in all cultures I am aware of, so I'd find it hard to imagine it doesn't have a good Darwinian explanation.

Cheers.

Hivemind187

Dave! wrote: »

Hey folks,

Thought it might be an interesting and useful idea to have a thread to speculate on and suggest explanations for particular traits or characteristics or anatomy.

For example, one might suggest that eyebrows on humans keep sweat from the eyes, so when fleeing from a predator or enemy, your vision is not adversely affected by your perspiration.

One that has been troubling me lately is laughter. What's the advantage of it? It's absolutely ubiquitous and has been in all cultures I am aware of, so I'd find it hard to imagine it doesn't have a good Darwinian explanation.

Cheers.

Also present in other primates (and some animal nuts will say that certain other mammals exhibit the vestages of "humour").

Likely this is something to do with familial bonding or the odd sensation of being put at ease by a smile (dolphins for example are perceived to be friendly because of an accident of the shape of their skull)

Nothingcompares

If we consider laughter to be a very obvious expression of happiness we can consider those that laugh to have the greater ability to convince others they were happy. This would in turn suggest the individual is content with regard to the fundamentals (food, water, shelter, health) and therefore a desirable mate.

laughter could also be seen as friendliness so you're less likely to be killed by a stranger if don't appear threatening.

Zillah

Laughter is a strange one though. Yes, you can laugh as a social bonding thing. But people can also laugh for all sorts of other reasons. We can laugh when we suddenly realise something we hadn't realised before, when we see an animal bump into a tree, when someone makes a reference to an event from our past. I have absolutely laughed my ass off without another person anywhere near.

The list is virtually endless, and often bizarre. The Greek philosopher Chrysippus laughed himself to death while watching a drunk donkey trying to eat figs. Go figure.

Dave!

Zillah wrote: »

The Greek philosopher Chrysippus laughed himself to death while watching a drunk donkey trying to eat figs.

Well that would be pretty f*cking funny tbh!

anti-venom

I think laughter has something to do with recognising patterns. If your brain recognises a surprising pattern it will reward you with an enjoyable sensation (laughter). Pattern recognition is fundamental to human cogniton and the evolution of laughter has encouraged us, as a species, to sharpen our cognitive skills.

That's why we don't find repeatedly hearing the same old jokes funny anymore. The surprise has gone and so there is little or no need for a reward for recognising it.

Dades

Apparently it's the best medicine.

Zombrex

Research has shown that laughter, particularly in other primates, doesn't have a whole lot to do with humor.

There has been some research that suggests that we have evolved laughter (possibly 1 million years before speech) as a method of putting others around us at ease. It appears to be a method to ease possible aggression from others.

This would explain why people tend to laugh or smile uncontrollably in nervous or tense situations (demonstrated in a scene from Full Metal Jacket where the Drill Sargent beats on of the cadets for sniggering at his shouts) particularly when they feel threatened by others.

Dave!

Any links to that research Wicky?

I find anti-venom's explanation quite intriguing too.

robindch

Zillah wrote: »

The Greek philosopher Chrysippus laughed himself to death while watching a drunk donkey trying to eat figs. Go figure.

Wikipedia claims that it was Chrysippus who fed the donkey the wine that plastered him, so perhaps he's the first case of indirect suicide by laughter? Can't think of a better way to go.

Anyhow, the 1974 documentary Animals are Beautiful People is worth watching for the scenes of monkeys, elephants and giraffes wobbling around the veldt pissed, and a few shots of them recovering the next morning.

I only narrowly missed doing a Chrysippus myself.

Zombrex

Dave! wrote: »

Any links to that research Wicky?

http://men.webmd.com/features/why-we-laugh

Dave!

Cheers son!

Another one (stemming from the thread about breast feeding in AH :pac: ) -- would I be right in thinking that the sexual desire/lust for women's breasts is a "by-product" of the breast being our first source of nutrition? Makes sense to me. But if that's the case, why do women not have the same level of lust for other women's breasts?

Or do they? OMG HOT

fitz0

Wicknight wrote: »

Research has shown that laughter, particularly in other primates, doesn't have a whole lot to do with humor.

There has been some research that suggests that we have evolved laughter (possibly 1 million years before speech) as a method of putting others around us at ease. It appears to be a method to ease possible aggression from others.

This would explain why people tend to laugh or smile uncontrollably in nervous or tense situations (demonstrated in a scene from Full Metal Jacket where the Drill Sargent beats on of the cadets for sniggering at his shouts) particularly when they feel threatened by others.

Ive found that laughing in those sort of situations usually gets me a smack in the teeth.

Zombrex

Dave! wrote: »

Cheers son!

Another one (stemming from the thread about breast feeding in AH :pac: ) -- would I be right in thinking that the sexual desire/lust for women's breasts is a "by-product" of the breast being our first source of nutrition? Makes sense to me

My understand is that male lust for women's breasts evolved along with us as we started to stand up right. Women's breasts increased in size as they mimic the visual appearance of a woman's bottom, the two round "humps" (as Black Eyed Peas would say) and the crack in the middle. The bottom when we were primates would have been the main visual attraction but the roundness and shape changed as we moved from crawling around the African planes to standing and walking upright. The bottom still is a main source of visual attaction in other primates.

So basically a womans cleavage attracts men because it reminds them of a womans bottom, or what a womans bottom looks like when she is bending over :eek:

This would also explain the common male desire for ... ahem ... titty w**ks ... but I will need a letter from your parents before I explain that one to you children...

AtomicHorror

Dave! wrote: »

Cheers son!

Another one (stemming from the thread about breast feeding in AH :pac: ) -- would I be right in thinking that the sexual desire/lust for women's breasts is a "by-product" of the breast being our first source of nutrition? Makes sense to me. But if that's the case, why do women not have the same level of lust for other women's breasts?

Or do they? OMG HOT

They're a visual indicator of fertility. There's also a hypothesis out there that they encourage copulation from the front, which works better for humans than other positions in terms of conception. Plus they're like, hot.

Edit: Wick gets there ahead of me on the position bit.

Dave!

AtomicHorror wrote: »

Plus they're like, hot.

Is that a direct quote from the Origin of Species?

Cheers lads

robindch

AtomicHorror wrote: »

Plus they're like, hot.

If there are any researchers out there short a volunteer or two, please PM me -- I think I'd like to be involved with the pointy end of this.

All in the name of science, of course.

AtomicHorror

Dave! wrote: »

Is that a direct quote from the Origin of Species?

Yeah I'm pretty sure it's in there somewhere.

robindch wrote: »

If there are any researchers out there short a volunteer or two, please PM me -- I think I'd like to be involved with the pointy end of this.

All in the name of science, of course.

Oh for the days when science was a pervy old boys club. The ladies outnumber the gents in biology these days. Not that I'm complaining about that.

The Mad Hatter

Wicknight wrote: »

My understand is that male lust for women's breasts evolved along with us as we started to stand up right. Women's breasts increased in size as they mimic the visual appearance of a woman's bottom, the two round "humps" (as Black Eyed Peas would say) and the crack in the middle. The bottom when we were primates would have been the main visual attraction but the roundness and shape changed as we moved from crawling around the African planes to standing and walking upright. The bottom still is a main source of visual attaction in other primates.

So basically a womans cleavage attracts men because it reminds them of a womans bottom, or what a womans bottom looks like when she is bending over :eek:

This would also explain the common male desire for ... ahem ... titty w**ks ... but I will need a letter from your parents before I explain that one to you children...

Oh? I'd heard (I forget where) that that hypothesis had been discredited.

Flamed Diving

I always laugh when I'm nervous. Anytime I'm having a serious quarrel with a g/f I start bursting my arse laughing. You should see the mayhem it causes!

Zombrex

The Mad Hatter wrote: »

Oh? I'd heard (I forget where) that that hypothesis had been discredited.

what, men don't like titty w**ks? :eek:

anti-venom

Wicknight wrote: »

what, men don't like titty w**ks? :eek:

It's not always practical, is it? Given some women's shapes you would need a six inch WIDE langer to make it work!

Zombrex

anti-venom wrote: »

It's not always practical, is it? Given some women's shapes you would need a six inch WIDE langer to make it work!

Your point? :cool:

anti-venom

Wicknight wrote: »

Your point? :cool:

It's not too shrouded a reference to small breasts and short range weaponry.

Dave!

Wicknight wrote: »

Your point? :cool:

So the legends are true?!?! :eek:

Galvasean

The Mad Hatter wrote: »

Oh? I'd heard (I forget where) that that hypothesis had been discredited.

Indeed. I taught the reason men went for big breasts is because it signifies an ability to lactate well, thereby increasing the chances of offspring surviving. This is at a subconscious level enticing for men. Same goes for wide hips, they signify an ease of passage for child birth.

Galvasean

Apparently, its all about symmetry.

http://news.nationalgeographic.com/news/2008/08/080818-body-symmetry.html

robindch

Gaviscon wrote: »

I taught the reason men went for big breasts is because it signifies an ability to lactate well, thereby increasing the chances of offspring surviving.

As above, this view seems to be false, though commonly held. I recall reading somewhere a couple of years back that human babies survive at a rate which is independent of the mother's breast size, leading one to suspect that this size is a sexual selection variable and has no survival-related value.

The Hottentots of South Africa's (kind-of) notwithstanding, I don't believe that increased hip/bum width has been shown conclusively to increase survival rates either.

Has anybody come across any, er, hands-on research in this area?

Zillah

I usually seize upon the idea that breasts are awesome because a good bountiful rack is likely to be able to feed my soon-to-be-conceived infant.

Of course this hypothesis goes without support, flopping around as I post.

pH

Apologies if I've nothing to add about the evolutionary basis of titty ****, however I've a question about sexual selection.

Given you accept peacock tails were formed by sexual selection, can sexual selection not explain anything with the answer "Just because females liked it"?

A secondary question is can sexual selection just explain features that are specific to one of the sexes, or can it explain features/traits that both males and females have in common?

Scofflaw

robindch wrote: »

As above, this view seems to be false, though commonly held. I recall reading somewhere a couple of years back that human babies survive at a rate which is independent of the mother's breast size, leading one to suspect that this size is a sexual selection variable and has no survival-related value.

The Hottentots of South Africa's (kind-of) notwithstanding, I don't believe that increased hip/bum width has been shown conclusively to increase survival rates either.

Has anybody come across any, er, hands-on research in this area?

I think it's more the case that the waist/hip ratio and perky breasts* are all indicators of youth and no prior children - thus, likely to be fertile, healthy, and not already committed elsewhere.

*it's not really size, although under a certain size might lead one to assume the girl in question is too young.

cordially,
Scofflaw