Here's Loren Cordain's riposte to the current findings:-
"Dr. Cordain was recently asked to comment on the articles
entitled "Mozambican Grass Seed Consumption During the
Middle Stone Age" by Julio Mercader in the journal Science,
and "Humans feasting on grains for at least 100,000 years,"
by Katherine Harmon Scientific American. Both articles cite
evidence that humans consumed grain much earlier than was
previously thought.
Dr. Cordain's response:
This is an interesting paper ( Mercader J. Mozambican grass
seed consumption during the middle stone age. Science
2009;326:1680-83) as it may push probable (but clearly not
definite) cereal grain consumption by hominins back to at least
105,000 years ago. Prior to this evidence, the earliest
exploitation of wild cereal grains was reported by Piperno
and colleagues at Ohalo II in Israel and dating to ~23,500
years ago (Nature 2004;430:670-73). As opposed to the Ohalo
II data in which a large saddle stone was discovered with
obvious repetitive grinding marks and embedded starch granules
attributed to a variety of grains and seeds that were
concurrently present with the artifact , the data from
Ngalue is less convincing for the use of cereal grains
as seasonal food. No associated intact grass seeds have been
discovered in the cave at Ngalue, nor were anvil stones
with repetitive grinding marks found. Hence, at best,
the data suggests sporadic use (and not necessarily
consumption) of grains at this early date. Clearly, large
scale processing of sorghum for consumption for extended
periods seems unlikely.
Further, It should be pointed out that consumption of wild
grass seeds of any kind requires extensive technology and
processing to yield a digestible and edible food that likely
did not exist 105,000 years ago. Harvesting of wild
grass seeds without some kind of technology (e.g.
sickles and scythes [not present at this time]) is
tedious and difficult at best. Additionally, containers
of some sort (baskets [not present at this time], pottery
[not present] or animal skin containers are needed to
collect the tiny grains. Many grain species require
flailing to separate the seed from the chaff and then
further winnowing ([baskets not present]), or animal
skins] to separate the seeds from the chaff. Intact
grains are not digestible by humans unless they are
first ground into a flour (which breaks down the cell
walls), and then cooked (typically in water – e.g.
boiling [technology not present]) or parched in a
fire which gelatinizes the starch granules, and thereby
makes them available for digestion and absorption. Because
each and every one of these processing steps requires
additional energy on the part of the gatherer, most
contemporary hunter gatherers did not exploit grains
except as starvation foods because they yielded such
little energy relative to the energy obtained (optimal
foraging theory).
If indeed the grinder/core axes with telltale starch
granules were used to make flour from sorghum seeds,
then the flour still had to be cooked to gelatinize the
starch granules to make it digestible. In Neolithic
peoples, grass seed flour most typically is mixed with
water to make a paste (dough) that is then cooked into flat
breads. It is highly unlikely that the technology or the
behavioral sophistication existed 105,000 years ago to
make flat breads. Whole grains can be parched intact
in fires, but this process is less effective than making
flour into a paste and cooking it to gelatinize the starch
granules. Hence, it is difficult to reconcile the chain of
events proposed by the authors (appearance of sorghum starch
granules on cobbles or grinders = pounding or grinding of
sorghum grains = consumption of sorghum). I wouldn't hang
my hat on this evidence indicating grains were necessarily
consumed by hominins at this early date. To my mind, the
Ohalo II data still represents the best earliest evidence
for grain consumption by hominins.
Cordially,
Loren Cordain, Ph.D., Professor
Paleo Diet Enterprises LLC"