Humans Are Omnivores
By: Dr. John McArdle, Ph.D
Laurie Forti Reviews This Article.
Dr. McArdle: There are a number of popular myths about vegetarianism that
have no scientific basis in fact. One of these myths is that man is naturally a
vegetarian because our bodies resemble plant eaters, not carnivores.
In fact we are omnivores, capable of either eating meat or plant foods. The
following addresses the unscientific theory of man being only a plant eater.
Laurie Forti: We will find that Dr. McArdle consistently fails to support his
thesis with real science by erroneously substituting cultural practices for
scientific facts and conclusions, the most common and fatal error of those
falsely claiming that humans are "omnivores".
Confusion Between Taxonomy And Diet
Dr. McArdle: Much of the misinformation on the issue of man's being a natural
vegetarian arises from confusion between taxonomic (in biology, the procedure
of classifying organisms in established categories) and dietary characteristics.
Laurie Forti: Right, these 'classifications' are Linnaean nomenclature which is
archaic, out-of-date, and based on insignificant, fragmentary fossilized data
alleging to track the human lineage, which should be completely overhauled in
light of modern genetic research. Dr. McArdle acclaimed "anatomist and
primatologist" at the PhD level, should be aware of this critical fact, and the
profound differences between Nature and culture, but we will see that he is not,
much to his own embarrassment.
Dr. McArdle: Members of the mammalian Order Carnivora may or may not be
exclusive meat eaters. Those, which eat only meat, are carnivores.
Laurie Forti: This is the crux of the matter, Dr. McArdle says: "you will see that
taxonomy is more of an art than a science, that there isn't even solid agreement
on which species belong in which orders, a little confusion is probably a good
thing to learn to accept when it comes to classifying animals."
Laurie Forti: So, we see that this non-science and confusion dominate
Dr. McArdle’s faulty presentation, and it is a primary cause for his false
conclusion that "Humans Are Omnivores". In fact, search as you will, there
is no taxonomical classification as "omnivore".
Dr. McArdle: Dietary adaptations are not limited by a simple dichotomy between
herbivores (strict vegetarians) and carnivores (strict meat-eaters), but include
frugivores (predominantly fruit), gramnivores (nuts, seeds, etc.), folivores
(leaves), insectivores (carnivore-insects and small vertebrates), etc.
It is also important to remember that the relation between the form
(anatomy/physiology) and function (behavior) is not always one to one.
Individual anatomical structures can serve one or more functions and similar
functions can be served by several forms.
Laurie Forti: A little truth has leaked out. These 'classifications' are mere
conveniences, not strictly defined in a reasonable, rigorous, scientific manner.
Dr. McArdle: The key category in the discussion of human diet is omnivores,
which are defined as generalized feeders, with neither carnivore nor herbivore
specializations for acquiring or processing food, and who are capable of
consuming and do consume both animal protein and vegetation.
They are basically opportunistic feeders (survive by eating what is available)
with more generalized anatomical and physiological traits, especially the
Laurie Forti: Notice, there is NO useful, meaningful, or even vaguely-scientific
anatomical, physiological, biochemical definition of "omnivore" and
Dr. McArdle foolishly ignores the inescapable fact that humans are totally
incapable of killing, tearing asunder, and consuming raw their prey with their
natural, biological equipment, as ALL natural omnivores do.
In fact, I have challenged people who adamantly claim that they are
"omnivores" for over 35 years to prove they are natural "omnivores" by
simply killing and eating raw a small animal with their natural equipment, and
none has ever done so to actually test their irrational belief. Not one.
Dr. McArdle has made the all-to-common and fatal error in his totally
unscientific and unsupportable claims by confusing Nature and Culture, a
grievous error, which most grade school children would not make.
Humans are clearly not natural "omnivores". Some are cultural "omnivores"
and indeed must rely on cultural artifacts to raise, kill, butcher, cook, disguise
with seasonings, cut up, and finally consume their animal prey.
Again, the false definition rests on the phrase "capable of consuming"
however, humans have no natural capability to do so. If they did, they would.
Thus, relying on an absurd false definition, Dr. McArdle inevitably and
inescapably comes to a false conclusion.
Another insight into the falsity of this concept rests in the mistaken confusion,
and proposed false-identity, of the verbs: to be, and to do.
Being refers to our genetic code and its consequences, while doing is totally
unrelated and a consequence of cultural programming.
Let's examine Dr. McArdle’s muddled "thinking" a bit to see how completely
absurd, and perhaps intentionally misleading, the "capable" definition really is.
Humans are "capable" of flying through the air; that makes us birds or flying
Humans are "capable" of traveling under water; that makes us fish or sea
Humans are "capable" of tunneling through the earth; that makes us
earthworms or moles, right?
Dr. McArdle: All the available evidence indicates that the natural human diet
is omnivorous and would include meat. We are not, however, required to
consume animal protein. We have a choice.
Laurie Forti: Another unintentional admission that we are not natural
omnivores; we have a choice; animals, however, do not have any choices,
they rely on their genetically programmed instincts to kill and eat animal prey.
Humans have no instincts to do so, in spite of the foolish claims of various
Instinct cults. Choices are cultural, not instinctual. How can someone with
even a trivial education not understand the profound difference between
Culture and Nature?
The Great Apes
Dr. McArdle: There are very few frugivores amongst the mammals in general,
and primates in particular.
Laurie Forti: Totally irrelevant, we are apes, not "mammals in general" nor
random primates. Actually, we are Pongidae, only the horrendous human ego
has chosen to elevate ourselves to another, exclusively ours, thus false
With a genetic difference of a mere -1.6% from the chimp, our closest genetic
relative, it should be obvious that our diet should be essentially that of the
Clearly, the genetic distances from various, scientifically-indefinable natural
"omnivores" would be much more, thus, again, refuting Dr. McArdle’s
unsupportable claim of "Humans Are Omnivores".
Dr. McArdle: The only apes that are predominantly fruit eaters (gibbons and
siamangs) are atypical for apes in many behavioral and ecological respects
and eat substantial amounts of vegetation.
Laurie Forti: Whoops - chimps are frugivorous, eating mostly fruit when
available, and falling back on leaves when sufficient fruit is not available, and
Dr. McArdle claims to be a primatologist.
Dr. McArdle: Our closest relatives among the apes are the chimpanzees (i.e.,
anatomically, behaviorally, genetically, and evolutionarily), who frequently kill
and eat other mammals (including other primates).
Laurie Forti: "Frequently" turns out to be a self-serving distortion, apparently
for the sake of his pre-conceived and false conclusion, and for a
"primatologist" it must be intentional.
Chimp hunting and flesh-eating is rare, 1.4% of their diet, not practiced among
all adults, as would be required by a true nutritional need, and is clearly
cultural, since flesh is used to gain sexual favors --humorously-similar to
Evidence Of Humans As Omnivores
Dr. McArdle: As far back as it can be traced, clearly the archeological record
indicates an omnivorous diet for humans that included meat. Our ancestry is
among the hunter/gatherers from the beginning.
Laurie Forti: More muddled "thinking". The "archeological record" so
referenced is purely self-selecting, thus misleading, since that "evidence" is
only produced by cultural processes, which include tool-marked bones and
evidence of fire.
The true frugivorous, natural, non-tool-using, human would leave NO evidence
at all, since all food wastes would be composted into oblivion. Tools produce
enduring evidence; raw-food eating humans do not; however that certainly
does not mean they did not exist. They exist today, and produce no long-term
"archeological evidence" of their diet in the local ecosystems.
Dr. McArdle: Once domestication of food sources began, it included both
animals and plants.
Laurie Forti: Whoops -- once culture is in play, its effects cannot be used to
assess the natural human. Anthro-apologists like to ignore this critical fact,
thus reducing their verbal output to mere exercises in creative writing, certainly
not real science.
Dr. McArdle: A relative number and distribution of cell types, as well as
structural specializations, are more important than overall length of the
intestine to determining a typical diet. Dogs are typical carnivores, but their
intestinal characteristics have more in common with omnivores. Wolves eat
quite a lot of plant material.
Laurie Forti: Totally irrelevant to humans. But, mindless insertion of
irrelevancies that sound correct is a common ploy of anthro-apologists
in order to create the illusion of scientific credibility.
Dr. McArdle: Nearly all plant eaters have fermenting vats (enlarged chambers
where foods sits and microbes attack it). Ruminants like cattle and deer have
forward sacs derived from remodeled esophagus and stomach. Horses, rhinos,
and columbine monkeys have posterior, hindgut sacs. Humans have no such
Laurie Forti: Again, factual but totally irrelevant to humans, or the "omnivore"
issue; this applies to herbivores, not frugivorous humans.
Dr. McArdle: Although evidence on the structure and function of human hands
and jaws, behavior, and evolutionary history also either support an omnivorous
diet or fail to support strict vegetarianism, the best evidence comes from our
The short canines in humans are a functional consequence of the enlarged
cranium and associated reduction of the size of the jaws. In primates, canines
function as both defense weapons and visual threat devices. Interestingly, the
primates with the largest canines (gorillas and gelada baboons) both have
basically vegetarian diets.
Laurie Forti: Love that self-contradiction.
Dr. McArdle: In archeological sites, broken human molars are most often
confused with broken premolars and molars of pigs, a classic omnivore. On the
other hand, some herbivores have well-developed incisors that are often
mistaken for those of human teeth when found in archeological excavations.
Laurie Forti: Yes, archaeology is confused and mistaken.
Dr. McArdle: These indicate we could be omnivores. Saliva and urine data vary,
depending on diet, not taxonomic group.
Laurie Forti: "Could"? Where is the evidence? Without evidence, "Could"
and "Could Not" are identical.
Dr. McArdle: Intestinal absorption is a surface area, not linear problem. Dogs
(which are carnivores) have intestinal specializations more characteristic of
omnivores than carnivores such as cats. The relative number of crypts and cell
types is a better indication of diet than simple length. We are intermediate
between the two groups.
Laurie Forti: More irrelevancies and errors to obfuscate the issue. We are
"intermediate" between a carnivore and another carnivore, so what does
Dr. McArdle: Humans are classic examples of omnivores in all relevant
Laurie Forti: This is a blatant lie. Dr. McArdle has presented no anatomical
definition, or even an attempt to generate a rigorous, testable, anatomical
definition of "omnivore" this is not possible, since the anatomies of various
natural omnivores are so diverse that no coherent patterns can be found.
Dr. McArdle: There is no basis in anatomy or physiology for the assumption
that humans are pre-adapted to the vegetarian diet.
Laurie Forti: The "vegetarian diet" is generally cooked, is centered on grains
and beans, and may include dairy and eggs; this was not a discussion of a
"vegetarian diet". Another irrelevant dodge and intentional obfuscation.
Dr. McArdle: For that reason, the best arguments in support of a meat-free diet
remain ecological, ethical, and health concerns.
Laurie Forti: The "ethical" argument is totally bogus, since there is no
objective set of ethics to which one can compare to determine what is more,
or less, "ethical" than what. That is, individuals just make up their own ethical
standards to suit their purposes of the moment.
Clearly Dr. McArdle is unqualified and hopelessly confused on very
fundamental facts and real science.
By: Laurie Forti
Article: Humans are Omnivores Review