Richard
Dawkins in his book, The Ancestor's
Tale, bemoans what he calls the Tyranny of the Dichotomous Mind. What he means is that when we look at the world around us, we tend to want to classify everything
into discrete groups. That makes some sort of sense after all, from
our perspective, the world is made out of discrete objects that it is
adaptive in an evolutionary sense for us to recognise. Being able to
distinguish a lion from a gazelle is certainly adaptive. This ability
to classify into distinct groups is not limited to humans. For instance
in a recent study by Chris Templeton (see
http://acp.eugraph.com/news/news05/templeton.html) suggest that at least some birds recognise different predators and
cnvey this information in their warning calls. Many organisms are able
to distinguish individuals that belong to their group from those that
do not. When you think about it this sort of dichotomous behavior in
very basic. Indeed, one of the things the immune system has to do
is discriminate between cells that belong in the body from those that
do not.
So given the obvious adaptive advantage to doing this sort of
classification, why does Dawkins speak of the Tyranny of the
dichotomous mind? First of all not all phenomena have sharp boundaries
as suggested by a dichotomy. Consider color. Most humans can look at an
individual monochromatic color swatch and classify it as to perceived
spectral color(Red, Orange, Yellow, Green, Blue, Violet). But when one
looks at the visible spectrum as a whole this gets more difficult since
it is clear that the colors blend in a continuous or if you will,
analog manner. Second of all, we confuse classification with the
thing itself. For instance Dawkins discusses some of the problems
inherent in trying to distinguish one biological species from another.
The boundaries are not at all clear in many cases. Indeed, I like to
tell my students that even were there no transitional fossils (and there
plently inspite of Creationist claims to the contrary), we have plenty
of evidence that the different kinds of organisms we see arise
from preexisting kinds. The evidence is in the messy boundaries we see
when we try to impose dichotomy on the species around us.
The tyranny of the dichotomous mind is related to another tyranny, I
call the "Tyranny of the Type" or Typological Tyranny. People who are
prone to this tyranny assume that objects have some sort of intrinsic
nature which defines a class of objects uniquely. Clearly this is
many times true, or else classification schemes would not be
feasable. Hunter gatherering tribes, with no formal training in
taxonomy recogise the same sorts of species of birds that a trained
taxomist might recognize at least most of the time. But this sort of
discreteness and non arbitraryness in many classification schemes is
often burdened with extra meaning which makes it difficult to deal with
some fundamental issues our society such as when does human life begin
or end, our identity in terms of gender or race and even our identity
as a species.
For instance Senator Brownback of Kansas proposed a bill
(S. 659—
The
Human Chimera Prohibition Act of 2005), which
bans the use of so called human chimeras. See h
ttp://www.asbmb.org/ASBMB/site.nsf/0/AF98278139BC60FB85256FE1006784A6?OpenDocument.
A chimera is defined in biology as an organism composed of cells from
unrelated organisms, two or more species. Chimeras are routinely used
today in plant biology and have become increasingly important in animal
biology to gain an understanding of animal development, including human
development. A good lay person's review of some of the ethical issues
raised by animal chimeras, especially chimeras involving human cells is
an article by
Maryann
Mott in National Geographic, which is very
heavily cited today. The ethical issues surrounding chimeras involving
human cells mixed with animal cells revolve around two basic concerns.
First is the concern about blurring the lines between humans and
animals: Brownback in a a recent
Lawrence Journal World article (
http://www2.ljworld.com/news/2005/jul/05/brownback_works_ban_humanhybrid_research/) notes:
“From the moral perspective, to create a human that is less than fully human or to create an animal that possesses particularly unique human aspects should be a serious concern for all of humankind”
and the text of his Senate Bill contains this narrative:
"Congress finds that-- advances in research and technology have made possible the creation of chimeras, which are beings with diverse human and non-human tissue; serious ethical objections are raised to some types of chimeras because they blur the lines between human and animal, male and female, parent and child, and one individual and another individual; respect for human dignity and the integrity of the human species may be threatened by chimeras; the uniqueness of individual human beings is manifested in a particular way through their brain and their reproductive organs/cells";
and...
"...with an increase in emerging zoonotic infection threatening the public health,
both domestically and abroad, chimeras present a particularly optimal means of genetic transfers that
could increase the efficiency or virulence of diseases threatening both
humans and animals."
This narrative points out the second concern, namely that the jump of
viruses and other infectious agents to humans from other animals could
be facilitated by animal human chimeras since the cells are obviously
in contact. Personally I think that Brownback is right to be concerned
about the ethics of chimeras and some sort of ethical guidelines, and
restrictions are needed. Indeed the National Academy of Science has
released a set of proposed ethical guidelines covering stem cell and
and chimera research:
http://www.nap.edu/books/0309096537/html/.
I suspect these guidelines will be controversial and it is going to
take sometime to reach a reasonable consensus. What I call your
attention to is Senator Brownback's comment about the integrety of the
human species and about blurring the lines between human and animal,
male and female...one individual and another. These are nice
sounding phrases, and as indivuals we don't like threats to our own
identity. As an aside I fund in amusing that we often want to tell
people what their identity ought to be in addition to be concerned
about our own identity. But banning human chimera research will
not prevent blurring of the lines between human and animal, male and
female parent and child, one individual and another because in biology
these lines are already blurred.
Not only are we perfectly good
animals, but it turns out we are also chimeras or at least have our
origin as a chimeric sort of relationship. First in our gut, we have a
large numbers of bacteria that live in a symbiotic relationship.
Even our cells are chimeral in nature. Consider that the mitochondria
in our cells apearantly arose from free living aerobic bacterial that
became associated with the ancestors of eukaryotic cells. Further there
is appearently lateral gene transfer between the mitochondrial genome
and the genome in the cell nucleus.
Above the cellular level, consider gender. The
concept of male and female useless for many groups of organisms. For instabce,
What's male and female in yeasts or in certain protists which have a
number of mating strains but the 'gametes' are the same size? What's
male and female in flowering plants that often have 'male' and 'female'
flower parts on the same plant and often in the same flower? In
non human animals- certain fish, such as clown fish, change from
male to female situationally. Even in humans- sex and gender lines are
blurred a lot more often the typical person might think. See Lynn
Conway h
ttp://ai.eecs.umich.edu/people/conway/TS/TSprevalence.htmlfor some interesting and eye opening estimates on the frequency of
transsexuality. Some of her numbers are inflated I suspect but the
point is even in humans some of our fundamental boundaries say between
male and female are blurred.
How about the distinction between humans and other animals? I am
astounded that my students seem blind to the fact that we humans
are perfectly good animals. As a species we may well have adaptations
that are unique to us, but as Dawkins notes, genetically the gap
between us and the rest of the apes is quite small. In fact we are so
close that even though chimpanzees are apparently our closest
relatives, some of us actually have certain genes (more precisely
alleles) found in Gorillas but not in Chimpanzees. What makes us human may be the
result of subtle changes in the timing and regulation of
developmental events related to the nervous system. Some scientists
have implied a few key events among them a mutation related to jaw size
and muscle attachment as being critical in human evolution. What
these key events are is not clear, but it seems to me that these events
are probably quite prosaic such that were we to go back in space and
time we would not be able to say "ah this ape is really human and this
one is not." It much the same as in our own lives where little events
may go unnoticed as being critical in shaping us exept with the benefit
of hindsight.
Darwin recognized that we really are not distinct from the rest of the
animals. This evolutionary kinship is reflected in our laws and
ethical stance toward other animals. Not anything goes: we have laws
against animal cruelty; animal experimentation today involves oversight
by animal care committies. Indeed there has been an ethical progression
toward increased concern and oversight about the treatment of animals.
When I was an undergraduate I was repeatedly warned to not be
anthropomorphic about othe animals because they don't have the same
sorts of cognitive abilities and awareness that we have. That is
true to some degree, but carried to an extreme, this
anti-anthropomorphic stance was used to justify cruel experimentation.
I am not an antivivisectionist but the recognition that we are not
separate from animals in a scientific sense clearly affects our ethical
stance toward non human animals and how we treat them as experimental
subjects.
I don't think it is any accident that the rise of animal
welfare organizations such as the SPCA stems from the time of
Darwin. Darwin was actually sometimes excessively
anthropomorphic, even giving earthworms greater credit for cognitive
abilities they do not really possess.
The tyranny of the type is still wide spread in medicine and
psychiatry, mercifully less so. But the idea is that there is a normal
physiological state for the human organism or perhaps some optimum
mental state and deviations from that are illness. So people
suffer from minor depression or mood swings and they take medication. A
child with ADHD is given Ritalin, a person whose body mass index is
above or below a certain level is considered obese or perhaps the
reverse. a person with a fever might take aspirin or some other
antipyretic to reduce the fever.
Now I am not arguing against use of medications; for me certain types of medications have literally been a life saver but sometimes the symptom may actually be an adaptive response. For instance, today we understand that fever is an adaptive
response to infection rather than an accidental symptom. The immune
system tends to work better at higher temperatures and higher
temperatures aslo seem to inhibit viral replication.
The tyranny of the dichotomous mind, the type: it divides us from
Nature; it divides us from each other and it divides us from ourselves
and from our own identies. It all springs from a logical fallacy that
since recognizing objects is an useful idea, it is therefore an over
arching idea that ought to apply to all spheres of our lives and yet it
clearly does not. The best analogy to the fallacy is from physics in
which we find Newtonian mechanics useful in our every day experience.
And yet, when we get down to very small scales we find that physics
becomes decidedly non Newtonian and particles become wavelike and we
struggle to hold two ideas at the same time and a multiplicity of
possibilities. It is not comfortable and we like comfort and cling to
the notion or either or, that we are human not animal, man or not
woman, normal or not normal and we find ourselves in a dysphoria of
comfort and wonder what is wrong.
