Ward Nicholson wrote:
>>Summary: density in terms of metabolic energy is *not* given with
>>animal carcasses (meat), except when only minor parts were used
>>(only the fatty brain and marrow or adipose).
>>Density *is* given in the form of fatty foods. Fatty foods in
>>paleo-africa are - nuts (about 300 g per day enough).
>>Tubers and roots (maniok e.g.) may also be a reasonable dense food.
>Nice try, but unfortunately there are two huge holes in this view of
>what fueled the bigger human brain:
A try with holes? I'll look at your counterargument.
>1. Paleo humans couldn't just drive to the grocery store to get all
>those nice bananas, nuts, and tubers. They had to expend a lot of
>energy were in
>season in the first place and even available certain parts of the
>year.
A living ecological system converts the sunlight energy of a given
area to a certain extent into biological plant energy
(wood, leaves, carbohydrates).
This may be after a time the energy present in a whole wood.
The plants, in the need of reproducing, again convert a percentage
of this, to fruit or other forms of their seeds.
In a certain stage of developement this fruit energy may be rather
high. For example a walnut forest throws down the protein and energy
for 14 persons to live on a area of only 1 ha (100*100 meters).
How many ha has a small groups area (30*30 kilometers)? 90000?
Lateron various animals convert this fruit and or plant bodies into
their own bodies.
Since animals have their own needs to grow and live from,
only a rather small percantage of the fed energy is found in
the animal- food for the predators.
Predators have a much smaller energy per area to live from.
If the available plants and fruit are not edible for a species living
in a certain area, then only specialized plant-eaters may live there.
Humans are very versatile eaters, able to come along with a very
broad range of food. African emerging gallery-woods are a good
environment for big trees standing in a little distance.
Good conditions for tree's seeds (nuts).
In the tropic, there are fruit (including nuts) available all year.
Natures idea, to support the seed spreading animals (and humans)
all year long.
> Whereas animals are available more or less all-year-round,....
> take less energy expenditure to get based on net energy
>return. Optimal foraging theory shows that on a NET CALORIC RETURN
>basis (i.e., available energy from a food minus the energy expended
>to obtain
>it), in a paleo environment, animal foods are more efficient to
>hunt/forage
>and would have provided the bulk of the calories.
Calories? Meat, but where are the calories?
I thought that gatherers/hunters had a very easy and rich life.
Much animal carcasses and plants available (small population).
So, optimal foraging wouldn't be an issue.
What do you think, how many nuts or tubers could you collect or
dig out during a whole day? 300g nuts or 2kg tubers are an effort of
a few minutes. But provide the energy for a whole day....
So, my point was and is:
What is the *best* food for a hominid with a brain getting bigger?
The *best* food must contain of *at least* some carbohydrates
because that's what brain needs.
Eeven if you think of ketosis. But i think you won't
assume australipithecus xy to be in ketosis in africa....
To a very big additional extent (about 80%) fats are a optimal
food.
But that's both not found in animal carcasses. So, if able to choose
it must have been fatty food items with some carbs, that dense foods.
Some zebras brains or nuts.
>2. Carbs, nuts, roots, etc., don't provide DHA, which is essential
>in building brains, especially bigger brains. Since humans are
>relatively inefficient in synthesizing DHA ...
DHA isn't the energy question.
But many nuts are superb in supplying n-3 fats, DHA stems from.
And nuts are the only staple fatty food item in africa
worth to mention.
I'd also like to discuss the DHA topic -as well as the vitamin,iron
and further topics. Provided you don't want to discuss if
vegan or vegetarian or meatatarian is "right" or not
(like i experienced the beyondveg site).
If i want to learn about the optimal food, this IMO isnt productive.
Probably early humans did consume some meat
(even if it may it be as little as the 4% insects like chimps).
That's not vegetarian. point. So what?
If there were some essentials in meat - grasshopper for example -
then i'd probably supplement what's missing, because i don't want
grasshoppers for some reason. And not leg of cow.
The rest should be our common interest.
>.... it is highly
>doubtful sufficient DHA could have been synthesized
>...
paleoways: who eats brains because of DHA?
Live long vegetarians, which never ate *any* DHA look quite
nice and active.
How could it be insufficient then?
Oh btw, life long meatatarians, which never ate DHA too.
>... there were no flaxseed oil bottles lying around...
But nuts.
But much more, this topic leads me to big amounts of fresh green
herbs and vegetables.
>There is also the problem that human brain size has decreased by 11%
>in the
>last 35,000 years and 8% in the last 10,000 which--since animal
>consumption has plummeted during the
>transition at the end of paleo times and the inception of
>agriculture--doesn't bode well for plant-based theories of human
>brain evolution.
Would you really relate such a long term developement to
the plummeting animal consumption (that you suspect).
If anatomical modern humans are our anchestors (any doubts?)
then we had a tremendous animal food *increase* after
moving to northern europe at about 35000 years ago.
Because there was the movement and the peak of the last
glaciation. Nearly *only* animals in winter.
The times before may be discussed (scavenger, zebra hunter,
gatherer), but *that* developement is clear.
And european hunter times lasted until linearbandkeramic,
at 4200BC. Before that were the mesolithic hunters and hazel eaters.
Oops when did this trend start?
But the best brain achievements were after neolithic times.
Do we need mega vitaminb1-doses for our brain? (Just a little joking)
I'm enjoying the discussion with you,
Amadeus
now heading home for a nice salad and fried mushrooms probably
--
Sent through Global Message Exchange - http://www.gmx.net
|
