|
The
Origin of Agriculture
By Steve Gagné
Theories
of Plant Domestication
In the distant
past, a few Homo sapiens made a decision that altered the biological,
psychological, and spiritual essence of humanity. That decision
was to work in partnership with the land through the domestication
of plants and animals. Researchers from numerous scientific disciplines
have made great strides in attempting to explain the origin of
agriculture. However, exactly when, how, and why this happened
at all is still very much a scientific mystery.
The information
gleaned from extensive research in this multi-disciplinary pursuit
has offered a range of insights into how humans adapt to social
and environmental pressures, develop patterns of health and disease,
and structure sophisticated forms of culture and civilization.
These ideas about agricultural origin are rooted in the cultural
evolution theory, which today serves as the basis upon which academic
beliefs and ideas are formed and supported by scientific research
and modern technology.
Much of this
research is based on fossil records, comprised of bones, seeds,
and stone tools gathered from caves, hearths, and wherever ancient
settlements can be uncovered. These records help us to formulate
possible circumstances for addressing the following questions:
1. Where
and when were plants first cultivated and identifiably domesticated?
2. What evidence is there to support current theories, and/or
what alternative interpretations can we draw from the available
evidence?
The Cultural
Evolution Theory, Methodology and the Fertile Crescent
The earliest
domestication of plants may have originated in the Near East's
“Fertile Crescent,” an area that stretches from the
eastern shore of the Mediterranean Sea and curves around like
a quarter moon to the Persian Gulf.
For nearly
two centuries, explorers and scientists from different parts of
the world have traversed this area in search of the origins of
civilization and agriculture. Einkorn and emmer wheat, barley
and lentils, goats and sheep all purportedly originated here between
5,000 and 10,000 years ago. Religious texts, legends, and archeological
discoveries document the antiquities of Sumer, Ur, Babylon and
other thriving cultural centers. This part of the Near East housed
a literal treasure trove of artifacts, bones, and seeds that would
be used to substantiate the cultural evolution theory. This archeological
evidence has helped create a consensus that has become the basis
of today's textbooks on ancient history.
The most thoroughly
researched area of the world for the advent of civilization, the
Fertile Crescent is held today as the model to which all other
such research sites throughout the world are compared. The Fertile
Crescent, goes the theory, is where it all began-agriculture,
civilization, all of it. Indeed, this “cradle of civilization”
idea is so entrenched a part of historical orthodoxy that its
axiomatic status has served to discredit those pieces of evidence
that seem to challenge it.
This sort
of fitting fact to theory is not new in scientific methodology.
Archeological and anthropological researchers commonly revise
initial testing results for findings; this is a normal part of
scientific procedure when deemed necessary. For example, South
and Central America are still termed “New World” countries,
the underlying assumption being that their development must postdate
that in the Near East.
However, increasing
amounts of controversial data are being found both in the Americans
and in parts of Asia. Such evidence is tested with a variety of
technologies, including accelerator mass spectrometry (AMS), which
is in essence an upgraded form of radiocarbon dating.
AMS can accurately date samples as small as a single grain while
detecting and reducing errors from fossil displacement. This can
be especially useful when a sample (say, of bone or seed) has
a different date than that of the strata. However, even with the
latest technology, much of the seed remains found are so severely
carbonized or decomposed as to make it extremely difficult to
determine whether a sample is wild or domestic.
Carbonized
seed remains are a common source of agricultural evidence. The
process of carbonization occurs when organic compounds are subjected
to high temperatures and converted into charcoal. While this process
does preserve remains for reliable analysis as to composition,
it also causes morphological changes that can make it difficult
to determine wild varieties from their domestic counterparts.
Among grass seeds, there is also the problem of trying to determine
the relationship, if any, between the wild grasses (emmer, einkorn,
and barley) of 10,000 years ago to those of the present. Wild
stands still grow throughout the Fertile Crescent and beyond.
The Independent
Location Theory
While ancient
plant remains have been extensively studied in the Near East,
such is not the case in the “New World.” Plant domestication
research in Mexico and South America involves about a half dozen
cave sites.
In Mexico,
samples of squash seeds and beans dating around 7,000 to 9,000
BP (“before present,” meaning before the radiocarbon
baseline of 1950)1 have been found in the deepest strata in some
of these caves. Domestic squash seeds found in a cave at Oaxaca,
for example, were dated at 9790 BP-the oldest date of any domestic
plant species found in the New World. Testing was based on dating
a charcoal sample found next to the seeds; because of the extreme
antiquity of the date, the seeds' age was immediately cast into
question. It was suggested that the seed samples had somehow been
displaced downward from the upper level of the cave; or alternatively,
that the charcoal sample had somehow been displaced upward from
the deeper layer.2 Both explanations are possible, yet one cannot
help but wonder why experts feel compelled to resort to such elaborate
reasoning when the discoveries occur in a location so far removed
from the established Near East cradle.
The Mexican
sites, furthermore, are not alone in this. The people of other
ancient civilizations from the Peruvian highlands, China's Yangtze
River valley, and parts of Egypt, India, and Papua New Guinea,
all may also have domesticated plants dating back as far as those
of the Fertile Crescent. However, the excavations for evidence
of agriculture at these locations are still in their infancy,
and cannot yet be compared to the extensive findings in the Fertile
Crescent.
Another part
of the world with a long history of agriculture is South Asia,
where a wide variety of annual and perennial forms of “wild”
or “free living” rice survives today without human intervention.
Not too many years ago, domestic rice was thought to have a history
of between 1,000 and 2,000 years; current findings have pushed
its origin back much further. The recent discovery of a handful
of rice, found in the village of Sorori in central Korea and dating
back 15,000 years, strongly suggests that an agricultural practice
here coincided with or even preceded that of the Fertile Crescent-where
agriculture is still held to have originated.
The age [of
the Sororian rice] challenges the accepted view that rice cultivation
originated in China about 12,000 years ago. . . .The region in
central Korea where the grains were found is one of the most important
sites for understanding the development of Stone Age man in Asia.3
After thousands
of years of cultivation, it is difficult to establish the identity
of the original wild progenitor of domestic rice. Researchers
struggle with whether present “free living” rice is
truly wild, a cultivated escapee, or something between: cross-pollination,
genetic exchange, expanding landscapes, and shrinking natural
habitats have distorted genetic qualities between wild and domestic
species. “Weedy” forms of rice have also evolved over
time, escaping into unmanaged natural habitats, flourishing at
the edges of agricultural landscapes, and exchanging genetic material
with both wild and cultivated varieties.
Even as they
wrestle with the problem of potential multiple domestication sites,
researchers are also faced with this paradox of the origins of
agriculture: Why did hunter-gathers begin domestication of plants
in areas with ample resources of wild foods? Thus, experts today
still cannot state conclusively where plants were first domesticated
and agriculture began-and the very hypothesis that it began because
of hunter-gatherers' need for a new food source is under challenge
as well.
Classification,
Morphology, and Genetic Testing
When determining
whether a plant should be classified as domestic, scientists look
for large and fast-sprouting seeds, glume (grain hull) adherence,
and strong rachises (the part of the grain that attaches the seed
to the stalk). These traits are considered markers of domestication
because, since they are naturally selected against in wild species,
they could evolve only under cultivation.
Large seed
size, for example, is usually considered a marker showing an adaptive
response to selective pressures relating to domestication. The
hunter-gatherer's deliberate planting of slightly larger, pre-selected
seeds from wild stands into seedbeds rather than into the plant's
natural wild habitat is believed to eventually cause morphological
changes in the plants, resulting in larger, domestic-type seeds.
By selecting wild mutant seeds with thinner glumes and stronger
rachises, early hunter-gatherers were able to build up a seed
supply of mutant seeds from wild stands over time. It is from
this supply of stored mutant seeds that domestic cereals are said
to have originated.
It is important
to know that, even with the multiple scientific disciplines used
to study agricultural origin, the sources of evidence vary considerably
in reliability. The three important founder grains from the Fertile
Crescent-emmer wheat, einkorn wheat, and barley-are the earliest
examples known to be located near their wild relatives. There
are several species growing today in the same area that are viewed
as possibly being the original ancestors of these domestics.
However, after
intensive study of morphologies and genetics, including analyses
of plant proteins and interfertility testing, we are often still
perplexed by a wild progenitor to which the domestic species appears
morphologically identical but with which it has no genetic compatibility.
To illustrate this “looks can be deceiving” aspect,
Daniel Zohary states:
A special
case of species diversity is provided by “sibling species,”
that is, taxa so similar morphologically that it is very difficult-or
even impossible-to distinguish between them by their appearance;
yet, crossing experiments and cytogenetic tests reveal that they
are already effectively separated from one another by reproductive
isolation barriers such as cross-incompatibility, hybrid inviability,
or hybrid sterility.4
A well-known
example of sibling-species relations is that of wild and domestic
emmer wheat. Triticum araraticumm, one species of wild wheat,
is morphologically indistinguishable from domestic emmer wheat.
However, all attempts to cross breed the two have failed, thus
proving that the former was not in fact the progenitor of the
latter. Furthermore, a true ancestor, morphologically different
from emmer wheat yet with identical chromosomes, was found and
successfully interbred, thus linking it credibly to emmer as a
potential wild progenitor.
Wild progenitors
used to be classified as separate species from domestics but are
now ranked along with the domestics as a separate subspecies.
For example, domestic emmer, Triticum turgidum, is the subspecies
dicoccum. Its suggested wild ancestor, once called Triticum dicoccoides,
is now classified as Triticum turgidum dicoccoides. What are the
most obvious differences between them? The domestic grain somehow
got larger, and the rachis got tougher and less brittle.
But are these
variations, together with the fact that interbreeding was successfully
accomplished under laboratory conditions, enough to identify Triticum
dicoccoides as the wild ancestor of domestic Triticum turgidum?
Or is there a danger here of leaping to simplistic conclusions?
We must remember
that numerous factors, such as changes in climate or animal and
human intervention, have influenced genetic variations and diversification
among the wild progenitors over thousands of years. While it is
generally believed that the wild progenitors of most cultivated
plants have been satisfactorily identified, many researchers recognize
the need for more data.
The simple identification of a morphological change does not,
in itself, constitute adequate documentation of a plant species
having been brought under domestication. Linkage must be provided
between the observed morphological change and a set of causal
behavior patterns. It is not enough simply to document phenotypic
change. It is also necessary to explain why such change appears
in response to a newly created environment of domestication.5
The example
of wild and domestic emmer, Triticum turgidum, may fit most additional
criteria for domestication, being that both the wild and domestic
emmer could successfully interbreed and had identical chromosomes.
Yet is it not possible that the putative wild ancestor of emmer
could in fact have once been a cultivated escapee itself, one
which then adapted to a wild environment over thousands of years?
Another example
is the fragments of emmer wheat dated 9,500 BP from the southwestern
tip of the Fertile Crescent at Jericho. Evidence as to whether
the fragments are wild or domestic is still inconclusive. Other
samples of emmer dated 9,700 BP and found just north of Jericho
near Damascus, however, are domestic.6 Keeping in mind these specimens
are thousands of years old and have been through extreme changes,
is it not possible that, again, what are thought to be wild samples
of emmer are simply genetically altered cultivars, that is, a
once-cultivated subspecies that has since run wild?
In order to
consider this possibility, we must reexamine the common assumptions
about our earliest agriculture origins: could these “origins”
in fact be examples of re-emergence from previous cycles of civilizations?
Without giving
this consideration due weight, we are left with the mysterious
appearance of numerous species of grasses, some of which share
similarities to cultivated grain species both genetically and
morphologically. One could argue that the dates of our examples
fit the conventional time line (10,000 years for domestication),
yet these are only a few examples of what has been found.
The recent
and totally unexpected find of several grains of morphologically
domestic emmer wheat at the Palestinian site of Nahal Oren also
raises the possibility that grain was under cultivation as early
as 14,000 BC.7
An archeological
site called Ohalo II in Israel reveals 19,000 well-preserved grass
grains. Among the specimens are pieces of wheat and barley dating
23,000 years ago8-about 7,000 years older than the Nahal Oren
samples cited above! In light of findings such as these, it seems
quite possible that many wild progenitors could be cultivars from
a civilization or civilizations predating the orthodox theory
for agricultural origin.
What are often
called wild progenitors of domestic grasses may be suspect for
other reasons. Several other sites in the Fertile Crescent have
combined specimens of wild and domestic emmer, einkorn, and barley.
The mix of wild progenitor and domestic is often interpreted as
signs of early cultivation from wild to domestic. However, these
may simply be examples of separate food stores for ruminants and
humans. And while animal domestication does not happen until around
8,000 BC, according to orthodox timelines, it is still possible
that a sufficient condition of pre-animal husbandry existed to
account for wild grass harvests.
Cultivars
and Wild-Growing Domestics
Einkorn wheat
represents another perplexing example of early wild and domestic
plant research.
The present-day
northern portion of the Fertile Crescent yields broad bands of
wild einkorn, yet research has designated the wild progenitor
of domesticated einkorn as being restricted to a small region
near the Karacadag mountains in southeast Turkey, far removed
from the northern broad bands of wild einkorn. If the northern
stands of wild einkorn are not the progenitors of domestic einkorn,
then what are they? Could they be a once-domestic species that
ran wild at some distant period of prehistory, eventually having
adapted to their present environment?
It is believed
that hunter-gatherers living in permanent settlements were harvesting
a species of wild einkorn 11,000 year ago along the Euphrates
River.9 If hunter-gatherers were already harvesting by that time,
perhaps they had been harvesting it for thousands of years before
that time. What species of wild einkorn was this? Was it the progenitor
of domestic einkorn, the species found in the Karacadag mountain
region? Or was it another species, like the one representing the
broad bands of the northern regions, a species that never became
domesticated?
For that matter,
what about the modern wild einkorn found in the area comprised
of Israel, Lebanon, southwest Syria and Jordan? This Palestinian
variety has large seeds, often larger than those of domestic wheat.10
Could these, too, be feral crops that were once cultivated in
antiquity and have now adapted to the regions? Large seed size
is considered a marker of domestication-yet this wild species
has seeds larger than most domestic species.
As long as
we are focused on the Fertile Crescent, let us consider the origin
and introduction of barley, the third founder crop of this region.
Two types
of domestic barley have been recovered here from early settlements.
It has been suggested that hunter-gatherers harvested wild barley
before domesticating two-rowed barley, followed shortly afterwards
by six-rowed barley. Between these two types, two-rowed barley
shows more of the wild barley characteristics; both two- and six-rowed
domestics have been found together in early settlements.
Wild barley,
like wild einkorn and emmer, develops brittle rachises for dispersal
when fully ripened. These rachises are segmented so individual
spikelets and grains can be shed from top to bottom when ripe.
Only about five to ten percent of the rachises are semi-tough
in wild barley, and this small percentage represents the average
amount of seed that is held to the stalk at the time of maturity.
According
to theory, early hunter-gatherers selectively chose seeds from
these specific stalks at an early stage before ripening; they
did so because even if the five to ten percent of rachises held
their seeds, at maturity they would immediately fall to the ground
when pulled by the hands of humans. The hunter-gatherers (so goes
the hypothesis) would have saved these partially ripened seeds
for planting stock.
In order to
be motivated to do this, these hunter-gatherers would have had
to believe that these wild grass seeds, after being planted in
homemade seedbeds, would produce larger, more stable seeds and
larger yields after a few generations. Are we to assume that they
knew what the outcome would be before they tried it? And are we
to further believe that these wild grasses could genetically morph
into domesticates through simple cultivation and planting techniques,
when it has still not been demonstrated today, nor is there any
evidence that such a demonstration is possible, that a wild, mutated
seed can be transformed into a domesticate through cultivation
in a foreign seedbed?
As with emmer
and einkorn wheat, it is not uncommon to find wild and domesticated
barley fragments together in archeological sites. In areas of
the Fertile Crescent, fully cultivated emmer wheat and two-rowed
barley have been recovered from ancient sites, accompanied by
wild-weed einkorn, ryegrass, and other weeds considered pre-adapted
to cultivation. It is still highly questionable whether or not
the selective pressures imposed on wild grasses, as suggested
by the cultural evolution model, caused the morphological changes
that resulted in domesticated varieties of cereals.
Early hunter-gatherers
were just as highly attuned to their food sources as modern day
hunter-gatherers. With hundreds of thousands of years' experience
in finding food, knowing which plants to eat, observing animals
in their natural habitats, and incorporating some of these habitats
into daily life, it is difficult to believe that these people,
who hunted and ate ruminants, were ignorant about the wild grasses
eaten by these animals. After all, countless generations of hunter-gatherers
used wild grasses for bedding, weaving baskets, and fuel. Could
these tough, brittle, wild grains really have been food for these
early people, as suggested by some leading specialists?
While there
is plenty of evidence for wild grain harvest, there is actually
little evidence supporting human consumption. Evidence for the
latter is restricted to a few Paleo feces found in caves. The
location and lack of evidence would suggest that a famine or climatic
disturbance might have been in effect, causing the humans to hole
up in the caves until it was safe to venture outside. If this
were the case, the usual foods may have become scarce, causing
those people to eat whatever they could find. (We must also consider
the possibility that Paleolithic peoples were able to process
wild grasses, rendering them digestible and fit for human consumption,
without the pottery to soak the grains or cook them, but this
possibility is quite slim.)
Proteins can
be useful genetic markers for distinguishing wild ancestors from
domestics. Shared genetic characteristics, if found, can reveal
the wild progenitor of the domestic. However, this methodology
is difficult to apply if the wild progenitor no longer exists,
as is often the case, leaving us with hypothetical ancestors that
must have been the progenitors of existing wild species.
Cross-pollination,
genetic exchange, and environmental changes have blurred the lines
between wild and domestic varieties over thousands of years. Along
the way, opportunistic weeds of many varieties have joined the
mix and contributed to new gene pools. In essence, it becomes
increasingly difficult to determine whether the domestics came
from weeds or the weeds came from the domestics.
A good case
in point is teosinte, a diverse group of wild grasses native
to Mexico, Guatemala, and Honduras.
Teosinte is
suspected to contain the progenitor of domestic maize because
the two are genetically compatible and successfully crossbreed
through repeated hybridization in fields. They differ, however,
in the morphology of the female ear. The few small seeds of teosinte
husks look nothing like the large, fully seeded ears of maize.
Teosinte has numerous branching stalks, each culminating in a
few small, shattering seed spikes. Corn, (maize) on the other
hand, is a single stalk containing an ear of tightly arranged,
rowed seeds that cannot disperse naturally.
Because of
its unique makeup, some experts believe teosinte to be a descendant
of domestic maize; most agronomy books and relevant literature
see it the other way around, and present teosinte as the wild
ancestor of maize. Yet regardless of which direction one subscribes
to, teosinte-to-maize or maize-to-teosinte, how such an extraordinary
transformation could have taken place in the remote past at all
is an inexplicable mystery.
Many varieties
and sizes of domesticated corn have been found in deep levels
of caves throughout Mexico, revealing the extensive knowledge
of plant genetics and breeding techniques among early inhabitants
of Mexico and Peru. A comparison of proteins between teosinte
and domestic maize reveals some similarities, and no species of
wild maize has yet been found. Some teosinte types have been categorized
as subspecies, yet there are no morphological indications of their
transformation into domestic maize.
With all our
current technology, it seems reasonable that we should be able
to create a domestic species from a wild one in a controlled environment,
simulating an early hunter-gathers' planting methods-if that is
indeed what happened. What would it take? In addition, if this
would prove the prevailing theory of wild mutant seed transformation,
why haven't we yet done it?
Identification
of chromosomal affinities between wild and domestic crops is another
method for finding wild progenitors. If cultivated crops show
full homology and interfertility with a wild species from the
same genus, then that wild species could be recognized as the
ancestor of the crop. This may be misleading, though, because
chromosomal affinity does not necessarily determine ancestry.
This is especially true when there are wide variations in morphology,
as is typical with many grain progenitors and their domesticated
offspring.
An obvious
advantage of domestication traits is that they evolved only under
cultivation and are strongly selected against and absent in the
wild.11
If this is
true, it should be easy to reverse the process and produce wild,
“shattering” crops from domestics once the specific
gene sequence is found. (“Shattering” crops are those
wild forms whose seeds drop to the ground upon ripening, rather
than adhering to their stalks, as do the seeds of domestics.)
…crosses
between wild progenitors and the cultivars have shown that this
shift is brought about by a recessive mutation in one major gene
or (more rarely) by a joint effort of two such genes. In all these
crops, breeders have also performed many intra-crop crosses (between
cultivars). Except for barley, none of these within-crop crosses
has been reported to produce wild-type brittle or dehiscent…12
It would appear
that our ancestors were able to “tweak” that single
gene from wild grasses so that it could not be reversed. Only
domestic barley, with its two independent recessive genes, has
successfully produced wild type, brittle grains and these are
still different from the “wild species.”
Aside from
wild chenopod pseudo-cereals that shed their seeds in a couple
of days at maturity and can be husked by simple rubbing and winnowing,
the idea of pre-agricultural peoples regularly consuming wild
grasses (progenitors of einkorn, emmer, barley, rye and spelt)
as promoted by some researchers may simply be an attempt to promote
and maintain the cultural evolution theory as applied to plant
domestication. The premise that Paleolithic humans ate wild grasses
that may have led to the eventual domestication of the wild species
also supports this gradual-step theory. This is not unlike the
theory that seed plant cultivation followed other vegetable plants.
Evidence for hunter-gatherers cultivating propagated vegetables
before seeds is lacking, but the theory of a gradual-step process
comfortably fits the current paradigm.
Could these
grass species of einkorn, barley, and emmer, so often suggested
as the wild progenitors of their modern day domesticates, be something
other than wild?
Based on the
hypothesis that over thousands of years a plant could experience
numerous morphological changes, is it not possible for a once-domesticated
plant to revert to some semblance of a wild version? We have already
mentioned how it has been suggested that wild grass species, once
cultivated, could morphologically transform within 300 years when
transplanted into seedbeds. An example of this morphological change
could appear as brittle rachises becoming “semi-tough”
enough to be identified as cultivated.
While this
may be possible, it raises another question: could other important
markers (thinner glumes, larger seeds, greater adaptation to climate
and soils, resistance to diseases and pests, etc.) that resulted
from selection pressures and were found in domestic species also
have morphed along with the rachises, or did some of these traits
occur earlier and others later?
Some of these
developments are major adjustments to a wild grass species involving
genetic manipulation at some level in the process, and there is
no indication these markers, not to mention increased nutrition
and faster sprouting time, could have occurred consecutively or
simultaneously over a few hundred years by being planted in seedbeds,
even if the seeds were carefully selected, wild, mutant seeds.
Granted, some hunter-gatherers from the epi-Paleolithic period
knew a great deal about the growing cycles of plants (and even
about seed planting and cultivation to some degree), but the genetic
manipulation of a wild grass species into a productive, nutritious
offspring is something quite extraordinary.
The question
thus remains: who were these people and how did they know how
to manipulate plants at the genetic level? Evidence at many archeological
sites indicates that the knowledge for plant domestication was
already there and was not an evolutionary process.
The idea that
many of these “wild” species of cereals are actually
cultivars is a realistic consideration. Edgar Anderson addresses
this important issue in his book Plants, Life and Man. He suggests
that we consider previous cycles of cultivation when examining
what we think are “wild relatives” of our basic food
crops.
This is indeed
a consideration for researchers, as it is now well known that
some species were in fact cultivated before the time they were
once thought to have originated. Corrections in origination dates,
along with genetic mixing of wild and domestic crops, environmental
pressures, and time can realistically contribute to de-evolution
of a domestic species.
An example
Anderson gives, of how one might encounter in a jungle a smaller
version of a cultivated fruit, giving the first impression that
it is a wild relative of the domestic version, is an all-too-common
occurrence. While it is possible that what you are witnessing
is a wild food, it has been repeatedly shown that many of these
wild-appearing foods are remnants of refuse heaps, a seed spit
out of a hunter's mouth after finishing his lunch from home where
he cultivated the fruit, or a garden escapee. I have personally
encountered wild-growing samples of cacao, coffee, papaya, avocado
and other familiar varieties while in the remote jungles, far
from any agricultural base, of South and Central America.
Anderson also
points out the great variations among wild-growing domestic avocados
in Central America. Such variations appear to an even greater
extent among avocados presently growing under managed cultivation.
He brings to attention the fact that apples appear in pastures,
forests and fields throughout the country, yet none were here
in America when the first European colonists arrived. Apples are
likely from Asia, where various species are native. We do not
know how much of a connection the wild-growing apples have with
previous cycles of cultivation, but they are, without question,
examples of cultivated apples that have run wild. The same is
likely true for many “wild” relatives of cereal grains.
At my home in Vermont, we have three apple trees and two pear
trees on our land. We were the first on record to build on this
particular spot yet, although we did not plant the trees, they
are not wild fruit trees.
Wild weeds
are highly successful plants that can easily overcome a disturbed
habitat, as evidenced in most gardens by weed races commonly found
among domestic annuals and perennials. Early hunter-gatherers,
like their modern counterparts, are known for having collected
and stored a variety of wild seeds. Most of these seeds are known
for specific uses, such as food or medicine. But what evidence
is there that pre-agricultural peoples actually used wild grasses
for their own consumption?
Jack Harlan,
an authority on agricultural origins, was able to prove that a
small group of people, within a period of just three weeks, could
harvest by hand enough wild grain to sustain themselves for one
year. To some, this classic study suggests that our ancestors
did the same. However, it does not prove that they did nor answer
why they did it if they did. Were harvests for pre-domestic ruminant
consumption, or for some other highly useful purpose?
Recently,
a team of international scientists found fields of wild einkorn
wheat in the Near East that provides the closest genetic match
to domestic einkorn. By obtaining DNA samples of 68 separate lines
of cultivated einkorn, all samples were found to be closely related.
DNA profiles were also taken from 261 separate populations of
wild einkorn in the same area. Of the 261 wild samples, 19 from
the volcanic region of the Karacadag Mountains in Turkey were
distinct from the other wild einkorn lines. Further analysis showed
that 11 of the 19 samples had a close phylogenetic similarity
to the cultivated einkorn. As a result, these 11 wild samples
could be identified as modern descendants of the wild progenitor
for einkorn wheat.13
Note that
these wild samples were identified not as wild progenitors but
as descendants of a wild progenitor, based on their similarity
to the domestics. But how can they credibly be seen as descendants
of a wild progenitor if we do not know where or what the wild
progenitor is? Phrases such as “similar to,” “related
to,” “descendants of,” and so on imply a link to
some long-lost original strain of wild grass that, through a series
of mutations, became the domestic grain we know today. Yet, in
many cases, there is still no actual progenitor.
Evidence does
strongly suggest an area for the earliest domestication of einkorn
wheat, but, like so many other domestic plants, the wild progenitor
remains elusive. What we have are suspected descendants of these
elusive wild progenitors, much like the situation in the study
of human origin with its search for the elusive “missing
link.”
The Process
of Cultivation and Other Theories
The presence
of grinding stones, sickle blades, and storage structures in many
early hunter-gatherer sites indicates a long reliance on wild
seeded plants, particularly wild grasses. Refinement of harvesting
and cultivation techniques by selectively choosing plumper seeds
eventually transformed fields of grain into crops with thinner
husks, stronger and less brittle rachises, stalks with increased
seed clusters, larger and more dependable yields after harvesting
and threshing, increased nutritional value, and spare seed for
storage. These newly cultivated crops could have eventually replaced
their wild counterparts in importance. After much trial and error,
these once-wild grasses, first through careful selection of suitable
wild seeds and later through repetitive cycles of sowing, reaping
and harvesting, became domestic crops fully dependent on human
intervention.
Some archeobotanists
believe morphological changes, which include changes in size,
shape and form, could have taken place anywhere from 100 to 300
years after the first time a seed was planted in a seedbed by
early hunter-gatherers. Others believe it may have taken longer,
up to 1,000 years. This is an interesting hypothesis that appears
to be based on sound evidence, albeit interpreted though the theory
of cultural evolution. Nevertheless, it is a hypothesis-not a
fact. The evidence is therefore open to interpretation from alternative
perspectives as well.
In Origins
and Seed, Gordon Hillman discusses cultivation as a precursor
to domestication and suggests that cultivation in the Jordan Valley
could have started as early as 12,000 BC. He further states, “However,
detecting the start of cultivation will, as ever, be problematic.”
The reasons for this, says Hillman, are that “cultivation
prior to domestication can be recognized only from indirect evidence,
not from the remains of crops themselves” and “domestication
itself is often difficult to detect.” Further influences
in the process would include unripe harvesting and genetic infiltration
of wild genes from neighboring populations of wild grasses.
Indeed, even
with the most rapid domestication, it is inevitable that “modifier
genes” would have ensured that the crops continued to contain
an admixture of wild forms for many centuries … This effect,
combined with the inherent problems of distinguishing wild and
domestic cereals from charred remains [archeological records],
ensures that detection of domestication in the archaeological
record will continue to be extremely difficult.14
So, why cultivate
in the first place? Why spend centuries planting something that
will not produce the desired result for generations? Furthermore,
when the plant finally does reach its full potential its product
becomes a causal factor, according to many historians, in both
the creation and downfall of civilization. Authority Jack Harlan
nicely sums up the scientific position on the question of cultivation:
What does
planting and reaping, planting and reaping, that is farming, do
to the genetic architecture of annual seed crops? Most of our
answers to this and similar questions have been intuitive or simple
guesswork.15
Again, while
there is no doubt that wild grasses played an important role in
the lives of hunter-gatherers, it may not have been for food.
What about
those 261 “wild” samples from the Fertile Crescent,
only 19 of which have genetic similarities to domestics? Could
these be additional examples of cultivars that have morphologically
reverted to their present status after running wild some thousands
of years ago?
Research has
shown that some early hunter-gatherers from the Fertile Crescent
practiced what is called vertical transhumance, wherein groups
of people would seasonally move their campsites from low elevations
to higher elevations in the spring to harvest ripening wild grasses
and to hunt wild goats and sheep that followed these ripening
grasses. If we remove the cultural evolution model as an interpretation
for this scenario, we are left with typical pastoralists herding
their flocks to ripening grasses. Admittedly, this would be at
a time well before they are believed to have had domestic animals-but
the truth of the matter is that, as with our inconclusive results
concerning plant domestication, we really do not know when animals
were first domesticated.
The majority
of researchers still either hold to the Fertile Crescent theory
or believe that plant domestication began independently in several
parts of the world within the last 5,000 to 10,000 years. Both
perspectives depend on the cultural evolution theory for their
basis. Either orientation posits a long period of experimenting
by hunter-gathers with wild grasses and roots predisposed to domestication
before agriculture appeared on a large scale.
But is it
possible, at least in some of the major areas where agriculture
began, that plant domestication did not happen through this evolutionary
process of human experimentation? Although it specifically addresses
contact between the hunter-gatherers and early farmers of central
and northern Europe, the editors of Last Hunters-First Farmers
offer another suggestion that could easily be applied to any number
of other locations where agriculture began:
The origin
of agriculture involves only a very few places in a few brief
moments of time. The spread of agriculture is the primary means
through which farming has become the basis of human subsistence.
It would seem essential to keep both colonization and adoption,
and the kinds of evidence and questions that they involve, in
mind in any discussion of the transition to agriculture.16 [Emphasis
added.]
Conclusions
Agricultural
origins cannot at present be conclusively proven to have begun
close to 10,000 years ago when additional evidence for agriculture
extends further back in prehistory. What can be unequivocally
stated is that agriculture had already emerged several times in
numerous parts of the world in the last 12,000 to 20,000 years,
and possibly as early as 50,000 years ago, with the last 6,000
years producing the most evidence for this cultural phenomenon.
New findings
challenge the hypothesis that humans first began as hunter-gatherers
and later evolved to agriculturists some 10,000 years ago-a hypothesis
that at present has no solid basis in proof, yet is readily believed
by many.
Genetic manipulation
of plants, particularly cereal grains, occurred at some point
in prehistory by people who already had the knowledge to do so.
These same people created a vital and lasting human food source,
no doubt for very specific reasons.
In each of
the major areas of the world where plants and animals were domesticated,
we find legends, both written and oral, describing the origin
of agriculture as a gift of the gods, culture-bearers who taught
indigenous peoples agriculture and the sciences of civilization.
(I have written about this elsewhere, in an article soon to be
posted on this site.) Could this possibly be coincidence, the
accident of mere imagination?
Our ancestors
left us more than bones, seeds, stone tools, priestly cults and
ritualistic incantations to exotic gods-they left us examples
of extraordinary feats of engineering, architecture and sustainable
methods of agriculture. They left us legends, myths, epics, and
sagas. Isn't it about time we hear them out?
1. A
Dictionary of Quaternary Acronyms and Abbreviations, www.scirpus.ca/cgi-bin/dictqaa.cgi?
Option=b; May 5, 2004.
2. Smith, Bruce D., The Emergence of Agriculture; Scientific
American Library; NY, New York; 1998, p. 165.
3. Dr. David Whitehouse, “World's 'Oldest' Rice Found,”
British Broadcasting Corporation News (BBC); October 21, 2003.
4. Harris, David R. (editor), The Origins and Spread of Agriculture
and Pastoralism in Eurasia; UCL Press, Ltd.; London, England;
1999 (paperback edition), p. 151.
5. Price, T. Douglas and Gebauer, Anne Birgitte (editors), Last
Hunters-First Farmers; School of American Research, Santa
Fe, NM; 1995, p. 198.
6. Smith, Bruce, cf. ante, p. 60.
7. Settegast, Mary, Plato Prehistorian; Lindisfarne Press;
Hudson, NY; 1990 (paperback edition), p. 3.
8. www.scientificamerican.com; June 22, 2004.
9. Smith, Bruce, cf. ante.
10. Harlan, Jack, The Living Fields; The Press Syndicate
(University of Cambridge), Cambridge, U.K.; 1995 (paperback
edition), p. 95.
11. Harris, David R., cf. ante, p. 154.
12. Ibid., page 154.
13. Smith, Bruce, cf. ante, p. 47.
14. Harris, David R., cf. ante, p. 194.
15. Harlan, Jack, cf. ante, p. 34.
16. Price and Gebauer, cf. ante, p. 126.
 |
 |
Home
I
Historical Network
I
History & Wisdom I
Alternative Genesis I
Genius of the Few
The Shining Ones
I
Path of Light I
Earth Under Fire
I
Origins and Spread...
Maps of Ancient Sea Kings
I
Atlantis I
Chronology
I
Science of the Soul
I
Crossing the Seas
History of Writing I
Words of Wisdom
I
Megalithic Structures
I
Ancient Technology
Scientific Papers
I
Archaeological
Papers I
Genetics & Genealogy
I
Prints & Texts
Conferences/Lectures/Events
I
Press Releases and Reports I
Recommended Reading
Golden Age Project Mailing
List I
Links I
Books
|
