>From: Ward Nicholson <[log in to unmask]>
>Something I have been considering lately is that while over
> the long-term, evolution optimizes the adaptation of a species to the
> mix of *overall* selection pressures it has to cope with, because the
> adaptation is to a *mix* of pressures, what you get in response is a
> "best-fit compromise" adaptation to that mix. In other words, evolution
> adapts to the real-world mix of factors (some of which may be at
>cross-purposes), so if you look atany one selection pressure, the level
> of adaptation may not be ideal just considering that one particular factor.
But it will be ideal considering
>the mix of pressures that must be adapted to as a whole.
Sometimes I think we give evolution way too much credit, & actually
what results is no great shakes, just what chance determined. On
another list I recently read that at 40,000 years BP (or was it
300,000) the estimate is 250,000 Neandertals in Europe, while
several million Homo sapiens lived all the way from Cape Town to
Siberia. The fact that we survived & the Neandertals didn't
(although on that list there has also been a quite compelling case
made recently that they did survive, & they are holed up in the U.S.
Congress) may have been more due to climatic changes in their
environment or other factors than anything profound. But I guess
this is just what evolution is always all about.
>There could be ways to exploit this. For instance, caloric
> restriction will increase longevity, but it obviously decreases muscularity
> which would have been very important to survival in prehistoric times,
>but not so much now. So if one is willing to sacrifice muscularity
> (which is also probablyeasier to achieve with animal foods if bodybuilders
> are any indication, even though there are of course *some* vegetarian
> bodybuilders), you can get the compensation of increased longevity.
I view muscularity as a negative. I used to be quite muscular, but
when I did my first long fast my muscles shrunk quite a bit. The
nice thing about being skinny is you can tell people you have AIDS.
This can come in handy when somebody is thinking about punching you
in the mouth.
>Of course, there may be any number of other effects too. For
> instance, when I started eating meat again after 18 years as a vegetarian,
> among other things my moods improved which subjectively felt like it was
> because of somewhat increased hormone levels.
This sounds a lot like cholesterol deficiency, & cholesterol is of
course used to make a lot of hormones. But it is also produced in
the body. DHEA (the master hormone) has gotten a lot of press
recently, but no way am I going to take it as it raises your body
temp. (& hence ages you quicker). What I am saying is that perhaps
there were deficiencies in your veg. diet which prevented the
production of sufficient hormones (& cholesterol), or you may have
been producing enough & everything above that level is just
superfluous & aging.
>Given that nutrients like iron, vitamin D, zinc, etc., are
> more bio-available in meat. (Better absorbed.)
They may be more absorbable, but I think (I know in the case of
iron) that these may well be pathological.
> Also there are nutrients like EPA which for all practical purposes is not
>available in plant foods inappreciable amounts, unless you go to great
>lengths like making flaxseedpreparations and so forth, but that still may not
>be enough.
I think you are on to something here Ward, & this may be at the core
of why all our homonid ancestors (& primate relatives) seek out
meat.
> And there is the standard argument that veggies like to make that natural
> plant foods contain "nutrients known and yet to be discovered" which is a
> good reason to eat them--and which can also be applied to meat for the
> same reasons.
Good point.
<Tabulated data snipped out>
>I am not entirely sure what to make of these figures, but two
> things seem to stand out. Longevity decreased slightly during the first
> several millennia after the introduction of agriculture when meat
> consumption went down and plant foods predominated, then gradually
>rebounded. It seems apparent therefore that meat itself could not have been the
> factor responsible for decreased longevity since *more* was eaten
> during Paleolithic times. On the other hand, the effect does not
> seem to have been too pronounced. From some of the later time periods involved
> where civilizations were known to be on the rise or fall, it
> appears that social factors have the biggest impact on longevity, particularly
> since longevity never rose above about age 45 for long, often falling below
> that figure for centuries at a time, until the 1900s, since which time it has
> almos doubled. That is what impresses me the most.
I don't think you can conclude anything from the data (even if they
are essentially correct). The big thing has been the drastic
extension of longevity in this century, supposedly due to the
elimination of infectious diseases as the leading cause of death. I
dopn't trust these data all that much, & there is a lot of
anthropological work on peoples living in the past few centuries
which suggests many individuals lived to great ages on primitive
diets. The certainly have been centennarians around for a long
time. (Indeed, it is almost a given in many cultures that there was
originally a "Garden of Eden" phase in which people lived a lot
longer prior to civilization.) We know humans live a lot longer
than apes, & we have wild apes today living at least as long as the
archaeological data show humans to have lived in the past few tens
of millennia. The problem is that much of the archaeological data
comes from skeletons found in areas well oustide our ideal tropical
habitat. In the moist tropics skeletal remains will quickly
disintegrate, leaving us no record.
>Also a response here to Mart Johnson and his comments about
> meat:
>I agree it may be true that if one looks only at modern
> primitives, they eat a good deal of their meat cooked, at least I think this
> is the case for Aborigines. I am not so sure it is the case for all modern
> primitives.
He's right Ward. Read "Our Primitive Contemporaries" by George P.
Murdock 1934.
>Oh, and about the Eskimos early deaths. The Americas were
> only colonized at the earliest around 12,000-13,000 years ago.
I believe current thinking is that this figure can be easily
quadrupled. The Land Bridge hypothesis has a lot of problems.
I don't have any sources right in front of me now, and these figgers might be
somewhat off, but I believethe Eskimos have only been in the Arctic something
like 3,000-4,000 years, maybe not quite that long. This is very little time to adapt.
> While undoubtedly some adaptation has taken place in that time, it
> is probably not complete, and they are likely still reaping the fallout
> of their incredibly high meat diets (about 90% meat before
> assimilation into modern culture), far above the late paleolithic average thought to
> be 35%. I think Doug is right their health and longevity would improve if
> they were to substantially decrease the meat in their diets.
Ward (& anybody else interested) should read something I have not:
the arctic explorer V. Steffanson's experience living for years at a
time on meat. (I think he lived to 82, but who knows how long he
would have lived if he had eaten less meat.) Linus Pauling went
into this & other stuff of interest in his outstanding "How to Live
Longer & Feel Better." Pauling also discusses:
Eaton, S. B.; Konner, M. 1985 Paleolithic Nutrition: A
Consideration of Its Nature & Current Implications New England J.
of Medicine 312:283-289
Pauling: (I'm paraphrasing)
*5,000,000 y.a. our primate ancestors were mainly vegetarians
*homonids split off & began eating more meat
*Homo sapiens appears ~45,000 y.a, eating ~50% meat
*European humans of about 30,000 y.a. were about 6" taller than
their agricultural descendants who ate a lot less meat
Same thing in the New World:
*Paleo-Indians of 10,000 y.a. ate lots of meat
*Indians of the pre-Columbian era were more agriculturalists
*latter ones were much shorter
*Since the Industrial Revolution our meat intake has risen back much
closer to ancient levels: "we are now nearly as tall as were the
first biologically modern human beings."
*wild game has only ~4% fat vs. 25-30% for domesticated
*grains predominate in modern diets, something they never did
*Eaton & Konner "conclude that 'The diet of our remote ancestors may
be a reference standard for modern human nutrition & a model for
defense agains certain "diseases of civilization."'
But that all it is, a reference standard. It may keep you healthy,
but the age at death will on average be much younger if you cut out
all the protein. Bottom line kids is that there is a clear inverse
relationship between height & longevity in humans. [Notice the
technique of saving the punch line for the end.]
--Doug Schwartz
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