Human, animals and Evolution.

Dont get fooled by the title, this isnt about bestiality so u can relax.

I was curious. Why is it that humans are so different.....no im not talking about countries or races.....im talking sexes.
Obviously theres the physical differences but the description that best sums it up is from a comedian i saw.
The female form is built for looks and performance. Curvacious and elegant its like a Sports car.
The male body is the exact opposite. Ugly as hell unless its been worked on but built for power.....kinda like a Humvee.

If you look in the animal kingdom for example. Besides the 'Display' creatures (Birds etc) most creatures are very similar and telling the two sexes apart is tough unless u start examining.

And another thing......why is human childbirth so painfull. In the wild u see a mother just slip out a kid with minimal fuss and be back on her feet in seconds. A human mother is lucky if she can get the damn melonhead forced out in under a couple of hours.


Also is it me or does it seem that the human race is evolving. Where i live its very rare u see a guy who's shorter than his father. Im 6ft 3 and one of the shortest in my class at college. And girls it seems are getting naturally slimmer etc. The number of stickthin girls in my area is pretty high too. Fair enough this could just be with the current culture with models and pop stars but even though were the same generation, those that are 16 seem much smaller, slimmer than the girls i went to school with, and im only 20.


Well theres my random rant for the week over.

by the way, sorry if somone decides this doesnt belong in this forum, its 2.30am and i just had the idea.

I think it belongs here since its asking your thoughts on....stuff. Things i think about so its 'How to....stop the voices in my head'

Seriously if a mod sees it move it to General or something. Id posted before i realised what forum i was in lol. Any thoughts from 'how to' are welcome though.

Re: Re: Human, animals and Evolution.

Emerald_eyed said:

No shit! I want to know this too.

I pondered and pondered. I came to the conclusion that it is going to hurt to push something the size of a watermelon, out the size of a golf ball.

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Thats what i mean, why have humans evolved for it to be so painfull. Are the powers that be telling us we shouldnt be breeding or something?

*Waits for the first generation to be born without Genitals*

Man theyre gonne ba a boring bunch.

Re: Re: Re: Human, animals and Evolution.

Re: Re: Re: Human, animals and Evolution.

UC_Gav said:

Thats what i mean, why have humans evolved for it to be so painfull. Are the powers that be telling us we shouldnt be breeding or something?

*Waits for the first generation to be born without Genitals*

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well, there are a few at Lit who should not breed.
As for being born without genitals, the same lot I mentioned lack testicular fortitude.

UC_Gav said:

If you look in the animal kingdom for example. Besides the 'Display' creatures (Birds etc) most creatures are very similar and telling the two sexes apart is tough unless u start examining.

And another thing......why is human childbirth so painfull. In the wild u see a mother just slip out a kid with minimal fuss and be back on her feet in seconds. A human mother is lucky if she can get the damn melonhead forced out in under a couple of hours.


Also is it me or does it seem that the human race is evolving. Where i live its very rare u see a guy who's shorter than his father.

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To answer your questions (I knew majoring in Bio would pay off someday):

1. Most of the external differences in the female body are the result of having to bear and care for young children- i.e. breasts, wide hips for childbirth, etc. Most animals that don't have a lot of differentiation between the sexes don't nurse their young or bear them alive.

2. Human childbirth is so painful because we evolved from primates. When we made the jump to human, evolution gave us a much bigger cranium (have to fit that brain in somewhere) without increasing the size of the cervix much. Most of the pain comes from trying to get that huge head out.

3. The overall increase in human height is actually only true for first-world countries, and is by and large the result of better nutrition. Growth in childhood and adolescence is heavily influenced by how well you were nourished as a child, and as more and more protein and calcium enters the diet, people get taller. Keep in mind that a couple generations ago, in our great-grandfathers' days, most families only had meat a few times a week, and not much milk or cheese unless they were on a farm.

Hope this answers your questions.

To add to what CollegeGuy said.

You have to keep in mind that we are also a bipedal species. To transfer the weight of our upper bodies thru to our feet we need a more robust hip structure. That coupled with the larger head makes childbirth harder for humans. Can’t speak of childbirth directly and never will since I’m a guy.
I also agree with the better nutrition argument. With better nutrition, humans are better able to express their genetic potential.

If you look in the animal kingdom you’ll find a correlation between F/M sizes and reproductive strategy. Species with large males and small females tend to run the male harem strategy. One male protecting and mating with as many females as he can control. Large size is advantageous since he can defend his harem.
Species that have males and females being relatively the same size tend to be monogamous. Usually this also includes child-rearing. This monogamous relationship can be permanent or last for one breeding season. That depends on the species.
Species with larger females tend to have male harems. Lots of examples of each variety and though it’s not always right, this theory tends to be true.

As for evolution, it’s likely that humans won’t evolve too much more or at least very quickly. Evolution is dependent on isolation so as we become more global in our “breeding” opportunities we will have a tendency to homogenize.

Good points CollegeGuy

. . .

Re: Re: Human, animals and Evolution.

Emerald_eyed said:

No shit! I want to know this too.

I pondered and pondered. I came to the conclusion that it is going to hurt to push something the size of a watermelon, out the size of a golf ball.

Click to expand...

I've seen something about women now trying a different position for labor that's supposedly easier. I've heard they squat & let gravity do its thing. I can't imagine being trussed up on a table with my feet up in stirrups as being comfortable for anything. Hopefully this new methodology will help ease the pain that a woman's got to go through.

I feel sorry for women and have respect for tem becaus of the pin they go through when they give birth.

I get kidney stones every so offen and they are very painfull just imagine when you pull velcro apart that is what happens to me the kidney stones have sharp spikes on them and they tear while pashing through the system for me it takes 8 hours if it was not for pain pills i would want to die.

To all women take care.

Given that evolution makes adjustments, such as increasing head size for more brain power, why didn't evolution make an adjustment to vagina size?

Smarter->Larger Head->Larger Vagina. Just scale everything up 25%.

Seems to me (I'm male) that childbirth problems/maternal deaths would start selecting for easier child birth. But why hasn't that happened?

And if have a larger penis gets more sexual contacts therefore more offspring, male penis size should also scale up. Women with larger vagina will seek penises large enough to have a pleasurable experience, which would give more sexual contacts with larger men. That pressure would scale up penis size until things "balanced" again.

So why hasn't mother nature just enlarged sex organs until birthing is easier?

Re: Re: Re: Human, animals and Evolution.

Re: Re: Re: Re: Human, animals and Evolution.

Emerald_eyed said:

Well women should have babies as God intended, Flat on their backs and numb from the forhead down

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Shouldn't it be "numb from the neck up" to ease the pains??

Before hospitals many cultures had child births in an upright position. My second child was delivered in the upright position. Really helps to have gravity on your side! As far as the size of sex organs is concerned, bigger penis does not mean more babies. Natural selection would choose men with more healthy sperms - not bigger cocks. And maybe women's vaginas ARE larger now than centuries ago? Now there's a topic for a thesis!

actually the human penis is the largest penis on any primate. you would also be surprised than most vertabrates the human penis is proprtiaonatly bigger than others in relation to there overall body structure. Also i think our male ego focuses in on our penis enought to make sixe a moot point next to pride

Re: Re: Re: Human, animals and Evolution.

De-lurking:

In addition to all previous points, the angle of the pelvis is another factor. Despite this, I think a lot of the pain has to do with diet and contemporary birthing practices. Many other cultures do not seem to have this problem. If you're pregnant, it's worth doing the research.

Edited for spelling

Re-lurking

I agree. I had both my children totally natural - no drugs - just breathing. I did LOTS of research and had lots of support (my mom had her 3 kids all natural) I think many women get the idea in their head that childbirth is like what you see on tv. God I wish they wouldn't show screaming women giving birth. I think doctors often make our fears even worse. I had to argue with the docs to LET me have natural childbirth the first time (this was 21 yrs. ago) and while stitching up my episiotomy (with NO pain killers - I was just doing deep breathing) the doc said, "Well if you'd have had a saddle block, this wouldn't hurt so bad." I had JUST given birth! What a bastard. It is amazing what you can talk your brain into doing for you.

Kudos to crazybbwgirl-you raised other interesting points. Although off topic, I think that the media AND doctors negatively influence your perceptions to a certain extent. If I never read anything or talked to my mother about it, I would personally never know that childbirth was never meant to be done on your back, or that it wasn't meant to be extremely painful.

I'm no medical expert, but doctors are questionable, too. The amount of C-sections and induced labours is alarming, and I just don't think that it's necessary. I think that doctors should be willing to provide the means in order to access the right kinds of information so that the patient can make an informed decision based on her own needs.

Returning to another issue at hand: The fact that girls are skinnier these days is once more due to acculturation. Parents tend not to "make" their kids eat healthy. I don't know what it's like elsewhere, but a number of my friends never have and probably never will eat their veggies. Many girls are also the product of mothers who obsess about their weight. Of course, this is something they pick up on, and is only re-emphasized by watching the television. Besides, most stick thin high school girls end up gaining weight when they get to university

Then again, obesity is a problem too. This side of the Atlantic is incredibly extreme.

I really wish that people had the desire to educate themselves.

ReadyOne said:

Given that evolution makes adjustments, such as increasing head size for more brain power, why didn't evolution make an adjustment to vagina size?

Smarter->Larger Head->Larger Vagina. Just scale everything up 25%.

Seems to me (I'm male) that childbirth problems/maternal deaths would start selecting for easier child birth. But why hasn't that happened?

And if have a larger penis gets more sexual contacts therefore more offspring, male penis size should also scale up. Women with larger vagina will seek penises large enough to have a pleasurable experience, which would give more sexual contacts with larger men. That pressure would scale up penis size until things "balanced" again.

So why hasn't mother nature just enlarged sex organs until birthing is easier?

Click to expand...

Evolution doesn't work like that.

As long as the offspring and the mother survive there's no evolutionary advantage to "Smarter->Larger Head->Larger Vagina". Equally true with penis size.

Evolution works on the theory "if it ain't broke, don't fix it"

Re: Re: Re: Human, animals and Evolution.

Lust Engine said:

I've seen something about women now trying a different position for labor that's supposedly easier. I've heard they squat & let gravity do its thing. I can't imagine being trussed up on a table with my feet up in stirrups as being comfortable for anything. Hopefully this new methodology will help ease the pain that a woman's got to go through.

Click to expand...

Actually, that's one of the oldest tricks in the book. It was just edited out during the major coming of Christianity. It was thought to be unholy.

It does help, though. Trust me!

Human cranium sizes had flattened out (after several million years of Homo species' enlargements) because women's pelvises had hit their limit for expansion while retaining the ability to be efficiently mobile while upright. Since female (and male) bodies had already undergone so many evolutionary modifications to get upright walking to work, those two benefits (upright mobility and larger braincase) became competitive, since helping one hurt the other.

Being able to haul ass was a greater advantage compared to a relatively small increase in cranium size, so selection pressure did not bring about further shifts in the shape of the pelvis. Otherwise...

... a parallel-universe scenario: relatively sedentary females in a race of big-headed humans. In this alternate humanity, women would eventually be left with just vestigial legs, or maybe tool-using feet. I wonder what effects this would have on the development of intelligence and technology.

Anyway - with C-Sections, though, that pelvis-size restraint is probably removed. As for the pain of childbirth- it doesn't seem to have any adverse effects on population growth, or willingness to do so.


As for genitalia size, the penis info was interesting. What I find much more fascinating, though, is the size of the testicles in relation to the rest of the body.

This, more than anything else, seemed to predict with stunning accuracy the sexual behaviors of primate species. Primates with small testicles relative to the rest of their bodies (like gorillas) have very clearly defined sexual relationships - either one male to many females, or relative monogamy. In those cases, it was rare for a female to mate with more than one male.

On the other hand, primate species with proportionally large testicles contained female populations that were more open to alternatives, if you get my meaning. The larger the relative size of the testicles, the more different partners females tended to have (in a single fertility period).

It all came down to sperm competition. Whoever produced more tended to have more descendents, and males that produced more sperm usually needed larger testicles to do it. But this is only true in species where sperm competition occurs - which rarely happened in cases like gorillas.

Humans fall in the mid-range, if I remember correctly, for relative testicle size.


Some people have noticed a trend in puberty hitting earlier than it used to. It turns out that it isn't hormones in our food, but just plain old fat. When girls hit a certain, precise body mass, their first menses happens within weeks. We're just a lot more well-fed than our ancestors (though there is a lower limit on when puberty can begin, it looks like).

As for 'natural selection' and 'sexual selection', there's random mutation to. Last year there was an article indicating that mutations can pile up and all get 'released' simultaneously when there is some level of acute stress. I think it was in SciAm, and was based in genetic research, so it's not something like "you won't like me when I'm angry" stress. But if something catastrophic happened (meteor impact, supernova), and the genepool shrank considerably -- it seems to fit in with the "punctuated equilibrium" model, and reconciles it with the slow and steady mutation/selection model.

[/knowitall]

Re: Re: Re: Re: Human, animals and Evolution.

entitled said:

Actually, that's one of the oldest tricks in the book. It was just edited out during the major coming of Christianity. It was thought to be unholy.

Click to expand...

Unholy?? That's a new one on me but it doesn't surprise me.

So they finally have some evidence on that stacking theory... I dont know how much i buy it, i mean.. Think of those primates. The larger testes came because of the promiscuity in their groups, not vice versa.

The way i look at it, things like testicle size, the evolutionary behaviors of men and women in groups, hair eye and skin colors, cosmetic sexual characteristics, those things are the slow grind of evolution, constantly working....currently humans have a HUGE gene pool, with almost no stresses (things that end life or reproductive ability)....the only way to force fast mass adaptation is to introduce a culling, an environmental stress that depletes said pool of people without some characteristic that makes them more likely to reproduce and push their genetic profile for another generation.

thats why sex makes the world go round.

D

CasusCoiti said:

Human cranium sizes had flattened out (after several million years of Homo species' enlargements) because women's pelvises had hit their limit for expansion while retaining the ability to be efficiently mobile while upright. Since female (and male) bodies had already undergone so many evolutionary modifications to get upright walking to work, those two benefits (upright mobility and larger braincase) became competitive, since helping one hurt the other.

Being able to haul ass was a greater advantage compared to a relatively small increase in cranium size, so selection pressure did not bring about further shifts in the shape of the pelvis. Otherwise...

... a parallel-universe scenario: relatively sedentary females in a race of big-headed humans. In this alternate humanity, women would eventually be left with just vestigial legs, or maybe tool-using feet. I wonder what effects this would have on the development of intelligence and technology.

Anyway - with C-Sections, though, that pelvis-size restraint is probably removed. As for the pain of childbirth- it doesn't seem to have any adverse effects on population growth, or willingness to do so.


As for genitalia size, the penis info was interesting. What I find much more fascinating, though, is the size of the testicles in relation to the rest of the body.

This, more than anything else, seemed to predict with stunning accuracy the sexual behaviors of primate species. Primates with small testicles relative to the rest of their bodies (like gorillas) have very clearly defined sexual relationships - either one male to many females, or relative monogamy. In those cases, it was rare for a female to mate with more than one male.

On the other hand, primate species with proportionally large testicles contained female populations that were more open to alternatives, if you get my meaning. The larger the relative size of the testicles, the more different partners females tended to have (in a single fertility period).

It all came down to sperm competition. Whoever produced more tended to have more descendents, and males that produced more sperm usually needed larger testicles to do it. But this is only true in species where sperm competition occurs - which rarely happened in cases like gorillas.

Humans fall in the mid-range, if I remember correctly, for relative testicle size.


Some people have noticed a trend in puberty hitting earlier than it used to. It turns out that it isn't hormones in our food, but just plain old fat. When girls hit a certain, precise body mass, their first menses happens within weeks. We're just a lot more well-fed than our ancestors (though there is a lower limit on when puberty can begin, it looks like).

As for 'natural selection' and 'sexual selection', there's random mutation to. Last year there was an article indicating that mutations can pile up and all get 'released' simultaneously when there is some level of acute stress. I think it was in SciAm, and was based in genetic research, so it's not something like "you won't like me when I'm angry" stress. But if something catastrophic happened (meteor impact, supernova), and the genepool shrank considerably -- it seems to fit in with the "punctuated equilibrium" model, and reconciles it with the slow and steady mutation/selection model.

[/knowitall]

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