Re: India: Three Year Old Runs Marathon Distances


"Jois" <firstjois@xxxxxxxxxxx> wrote in message
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>
> "deowll" <deowll@xxxxxxxxxxxxx> wrote in message
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>>
>> "Jois" <firstjois@xxxxxxxxxxx> wrote in message
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>> >
>> > "deowll" <deowll@xxxxxxxxxxxxx> wrote in message
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>> >>
>> >> "spiznet" <mark@xxxxxxxxxxx> wrote in message
>> >> news:1132185943.727990.287070@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> [snip]
>
>> > See:
>> > http://www.worldbank.org/html/extdr/hnp/population/ynglives/ynglives.htm
>> >
>> > Related Complications
>> > Pregnancy in adolescence carries a relatively high risk of death or
>> > long-term complications.
>> > Pregnant teens are more likely to suffer from malnutrition,
>> > pregnancy-induced hypertension, and eclampsia than women over age 20.
>> > In
>> > addition, an immature birth canal may prolong labor, increase the risk
> of
>> > vesicovaginal fistula, cause permanent damage to bladder and bowels and
> to
>> > the infant's brain, or lead to death of mother and child.
>> > Young mothers, ages 15-19, are twice as likely to die of
> pregnancy-related
>> > causes than women ages 20-24. The risk of death may be five times
>> > higher
>> > for
>> > girls ages 10-14 than for women 20-24.
>>
>> Then natural selection failed. I'm not being snide but one study of very
>> early native Americans found the oldest female was about 24 at the time
> she
>> died. I don't have a clue why women aren't equipped to safely reproduce
>> at
>> the age we have every reason to believe most early females were
> reproducing
>> but the data is what it is.
>
> But is that right? Did natural selection fail? Look at this:
>
> http://nationalzoo.si.edu/Animals/Primates/Facts/FactSheets/Gorillas/default.cfm
>
> Reproduction
>
> Female gorillas reach maturity at seven or eight years old, but they
> usually
> don't breed until ten years or older.
>
> Due to competition between males for access to females, few wild males
> breed
> before they reach 15 years old. Eight and a half months after mating, a
> female gives birth to one young, which can usually walk within three to
> six
> months. Young are usually weaned by three years old, and females can give
> birth every four years.
>
> Upon reaching sexual maturity, between ages seven and ten, young gorillas
> strike out on their own, seeking new groups or mates. Zoo gorillas may
> reach
> sexual maturity before seven years old, and may have young every two to
> three years.
>
> Life Span
> Gorillas may live about 35 years in the wild, and up to 54 in zoos.
> -----------
>
> So, Gorillas have 2-3 years between "maturity" and reproduction. And so
> do
> we. I don't see that as failure. I think the same thing happens with
> most
> mammals - there is a space of time between maturity and reproduction.
> Maybe
> that could be further specified as "There is a space of time between
> sexual
> maturity and mental maturity and reproduction." But that might be
> another
> argument.
>
> If the oldest female is a group died at 24 years of age then there
> probably
> must have been something wrong with that group. Maybe they were sick or
> couldn't feed themselves - some other factor that made their group not too
> successful.

It was all of North America south of the Ice sheets but in fact the bodies
all came from locations near the Northern edge of the lower 48 I think. I'm
left wondering if maybe they missed a few longer lived females.

>
> I thought it was evident that the nutritional status of the female
> determined the age of sexual maturity. This would be "natural
> selection's"
> method of birth control or maybe population control. If the group were
> not
> getting enough nourishment to establish menarche for females then the
> group's population would not be increasing. They couldn't feed the
> population they already had. If the group could feed all of it population
> the females would hit menarche at a relatively early age, if it could not
> (I
> think Europe at one time had an average age of menarche at 15-16 - poor
> food
> supply) menarche would be delayed.
>
>> I don't know of another mammal species that runs the risks from simple
>> reproduction that human females seem to run. It's really weird but I
>> don't
>> know of anything that would explain it. Many women seem to do fine but a
>> major chunk don't. How you can pass on genes causing you to die in child
>> birth for thousands of generations escapes me.
>
> I think of this part of the problem as natural human variation. Hip width
> and height and skull size varies between different populations and when we
> mix and mate outside of our own groups we run the risk of incompatibility
> baby-mother. Europeans are supposed to have the widest hips which should
> translate to easier baby delivery but is every European exactly like every
> other European? Trace their roots to Neanderthals or Indians?

I think you may have a point. Philip D. noted that some genes don't work
well when combined. I believe we were talking about teeth at the time.

I would also note that some small women seem to have have born a lot of kids
with few problems and my most robust female relative darn near died in child
birth. The pelvis actually opens a little during child birth and maybe hers
didn't. In any event after a labor that lasted something over 30 hours she
decided to never do that again.

On the other hand my smallest known female (great grand mother) relative at
about 4' 3" had a dozen kids including a set of twins. She wore a size four
shoe.

I'm not sure how size of the mother reflects on ease of birth. The obvious
thought would have been small women are more likely to have problems.


>
>>
>> I don't buy the big brain claim as being the total cause because many
> women
>> do fine. The question is why do we still have so many that can't have a
> baby
>> without a c-section
>
> You might need to look at brand new babies and see how the heads are
> molded
> to get through the birth canal. They do get squashed and lumps on their
> heads from being squashed up, etc. If everyone stayed in their own
> villages
> and married among themselves all the time we might have eventually weeded
> out fathers with large hat sizes and women whose hips were too narrow to
> deliver babies safely. But we don't stay still.
>
> How much variation is there between gorilla females? Males? Are they as
> varied as we are? And who says they have an easy time of it?
>
>> or being way past the point they became fertile and
>> sexually active.
>>
>
I may not have been clear. I think it is bad design to have some one become
firtile and sexually active long before they are old enough to safely
reproduce.

Don't tell anyone that I said this but it might not have been all bad if
they appeared to be firtile and did some courting before they became
firtile. It takes a while to tell the winners from the losers.

I do note that in many/most stable societies females who hit puberty young
may have been protected by taboos with at least some fangs. Of course I can
name a lot of major socieities in which that sort of protection obviously
wasn't offered to all females.

It is worth noting that elephant populations that have been subjected to
extreme reduction had very young females calving. Maybe this is some sort of
defense mechanism for populations in which life is short and you have to
breed early to have a shot at getting genes into the next generation?

More likely its just random variation that works that way under some
conditions.


> I don't get this last part.
> [snip]
>
> Jois
>
>


.

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