Comparative Anatomy & Taxonomy
By: John Coleman
Comparative anatomy works on the simple and demonstrable fact that the
biological form usually defines function. Human is closest to frugivore animals
(fruit eaters), from the anatomical and taxonomic point of view.
Certainly science does not really validate the typical vegan diet, as this serves
cultural imperatives. Science provides us with an indicator of human nutrition
which was not established by culture, but is certainly that of a herbivore or
frugivore and not a carnivore or omnivore.
The Opportunistic Feeder Theory
Various folk promote the opportunistic feeder theory, which suggests that
because man can or has fed on meat, eggs, insects and other animal matter,
then man is an opportunistic omnivore.
This theory also counters the conclusions of taxonomy presented above,
suggesting it is misleading and that species have individual feeding habits and
cannot be pigeonholed as taxonomy suggests. The basis of this argument is
that animal behaviour and adaptability indicates dietary suitability.
This theory is false and unscientific. Of course tradition is not scientific, and
the practice of humans eating meat is old, but has nothing to do with what we
are biologically equipped to feed upon.
We ate meat to survive; now we eat it out of habit and not need.
Another quasi-scientific theory is associated with the opportunistic feeder
theory. This can be called the biochemical individuality theory, which is often
seen, in far eastern "medicines" such as Traditional Chinese Medicine, and the
This theory suggests that since we are biochemically individual we should all
eat individual diets suited to our moods, illnesses and other contrived
The logic behind biochemical individuality theory is fallacious, for although we
are all unique biochemical beings, we are predominantly the same biochemical
system, with low-level variations. At the molecular level we differ, at the system
level we are alike.
If anyone imagines they can adjust their diet according to these individual
metabolic variations, they are fooling themselves.
By picking only the low-level system differences to indicate information about
dietary choices, or moods, yin and yang and so forth, and extrapolating to the
whole, we produce a gross misrepresentation of the facts.
As far as we know, all cattle graze, all lions eat raw flesh, all chimps eat a diet of
mainly raw fruit and vegetation and all chickens peck for grubs and grains.
No animal on earth that we know of cooks its food before eating it, except
humans. Only human behavior breaks the taxonomic definition that science
defines for it.
Humans prefer culture and technology over nature, and since our natural role
is as a raw food herbivore, and because our bodies are only suited to that role,
any significant perversion of it must, and does, lead to ill health.
One cannot choose what to eat healthily, based on cultural imperatives since
one will most likely present the wrong kind and quantity of precursor
molecules, as well as introducing poisons to the body. A healthy human body
cannot be operated on the wrong chemical inputs. "Garbage in equals garbage
Our anatomy is clearly unsuited to deal with animal matter in the diet, however
our digestive chemistry can deal with animal tissues and obtain some nutrition.
But this does not indicate biological suitability or desirability. Cattle, which are
herbivorous ruminants, may eat many insects while they feed, chimps may
occasionally kill and eat a small monkey. A pet cat may eat bread and
margarine. So what?
Are cattle to be defined as insectivores or omnivores, or opportunistic feeders?
Is the pet cat an opportunistic feeder? Certainly, and the chimp an
opportunistic feeder? Why not.
None of this distorts taxonomy or surprises the biologist. All herbivores will
be able to process animal protein to some degree or other since all protein is
It is possible with modern processing methods to produce a "cat food" derived
solely from plant material and non-animal matter that will keep a cat alive. Is
this a herbivorous cat? No, it is a domestic animal eating an industrial diet.
Higher life forms display a broader range of behaviors, and feeding behavior
simply reflects this, but does not reflect our true biological feeding
The opportunistic feeder theory is based on circular logic, "I do therefore I am"
and is hard to falsify, since at a molecular level, food is chemically similar,
because all animal tissues are made up of broken down plant tissues.
The fact that opportunistic feeding theory is circular and hard to falsify makes
it unscientific, and useless in any discussion of what humans should eat.
Taxonomy is accurate, logical but not exact. Since there are exceptions it is
A statement that cannot be falsified is unscientific, e.g. the statement: "The sun
will extinguish in 1000 years time" is unscientific because nobody can
demonstrate that this cannot happen.
By: John Coleman
Article: Comparative Anatomy & Taxonomy