[Bert Latamore]

Bert Latamore asked the Naked Scientists:
   
Why do human females have breasts?

I do not mean mammary organs but rather prominent, large breasts for their entire adult lives. As far as I can tell this is unique to the human species: In every other mammal species the female's mammaries only enlarge when the females are pregnant/nursing and otherwise are totally flat against the chest.

From an evolutionary standpoint, I can think of a list of reasons that having large breasts are an evolutionary disadvantage to humans in their natural (e.g., hunter-gatherer) state.

So why did they evolve?

What do you think?

[JnA]

Breasts are largely made up of fat. Fat prevents heat loss, it takes a lot of heat to produce milk... maybe something in that?

I have heard the shape helps human babies (with their non prominent jaws) feed without suffocating. Perhaps the development of breasts at puberty is more energy efficient for the body that having 'another job to do' while the woman is pregnant...

or perhaps larger breasts (caused by puberty hormones) weren't enough of a disadvantage to not form.


I'd love to hear your list of reasons.

[neilep]

I'm just glad they do !

[Pwee]

There is an evolutionary explanation for this. As in the case of most evolutionary theories, this can't really be tested, but anyway:

Most female mammals have their reproductive organs facing outwards (backwards) at approximately head level, they are quite visible. This helps attracting males and give signals about fertility etc.

Unfortunately as we started to walk upright, these important reproductive cues (the sight of the vagina and the buttocks) got further away, the vagina got concealed between the legs and the whole thing was not at head-level anymore.
Those women who could mimic these visual cues up closer to eye level of the possible mates could get their "sexual attention" more easily.

These "fake" cues are the large breasts that mimic the buttocks and the large red lips that mimic the vagina.
If you don't believe me, believe your own eyes. Here is a little home experiment that you can try out yourself:
Boobs, butt or shoulder?
See attached images too.

[Don_1]

ME TOO SHEEPY!!!

I love it in the summer,
When the sun comes out to play.
It's warming rays make us happy,
On a fine summery day.

The girls all look so pretty,
And its really worth the fuss.
They catch my eye as I drive by,
And nearly into the back of a bus.

Those lovely legs and mini skirts
They brighten up our city's.
A tight and deep cut silky top,
Which reveals their wonderful .......

******Curses, I'm stuck for a word to finish off my little rhyme, any suggestions anyone?******

[neilep]

ME TOO SHEEPY!!!

I love it in the summer,
When the sun comes out to play.
It's warming rays make us happy,
On a fine summery day.

The girls all look so pretty,
And its really worth the fuss.
They catch my eye as I drive by,
And nearly into the back of a bus.

Those lovely legs and mini skirts
They brighten up our city's.
A tight and deep cut silky top,
Which reveals their wonderful ......WAISTLINE !!.  []

******Curses, I'm stuck for a word to finish off my little rhyme, any suggestions anyone?******

Excellent poetry !!..don is great !!

[Karen W.]

LOL..LOL.. Competition for a mate!

[Don_1]

ME TOO SHEEPY!!!

I love it in the summer,
When the sun comes out to play.
It's warming rays make us happy,
On a fine summery day.

The girls all look so pretty,
And its really worth the fuss.
They catch my eye as I drive by,
And nearly into the back of a bus.

Those lovely legs and mini skirts
They brighten up our city's.
A tight and deep cut silky top,
Which reveals their wonderful ......WAISTLINE !!.  []

******Curses, I'm stuck for a word to finish off my little rhyme, any suggestions anyone?******

Excellent poetry !!..don is great !!

That should fit the bill nicely Sheepy. Will I ever attain your supreme standard?

[neilep]

ME TOO SHEEPY!!!

I love it in the summer,
When the sun comes out to play.
It's warming rays make us happy,
On a fine summery day.

The girls all look so pretty,
And its really worth the fuss.
They catch my eye as I drive by,
And nearly into the back of a bus.

Those lovely legs and mini skirts
They brighten up our city's.
A tight and deep cut silky top,
Which reveals their wonderful ......WAISTLINE !!.  []

******Curses, I'm stuck for a word to finish off my little rhyme, any suggestions anyone?******

Excellent poetry !!..don is great !!

That should fit the bill nicely Sheepy. Will I ever attain your supreme standard?

Thanks Don..I think it has a nice ring to it !!  []

Attain my standard ?...ewe overtook me on your very first post ! [:I]

[neilep]

Could all female members please display their boobs ?..This is for some empirical research that I will be conducting !

thanks

[Don_1]

Could all female members please display their boobs ?..This is for some empirical research that I will be conducting !

thanks

HOLD ON A JIFFY...........



OK, I'm ready!

[Pwee]

Most of a breast consists of subcutaneous fat, which the body creates mainly on the torso to store energy.  Humans display sexual dimorphism regarding subcutaneous fat, with women generally exhibiting a greater “adiposity” than men.  This is due to women’s bodies converting more of their food into fat than men’s bodies do. 

The answer has to adress the issue of the placement (why on the front of the chest) and the lack of large breasts on other mammals too. The answer I gave accounts for both of them.