PROFILE: MARGIE PROFET

       Evolutionary Theories for Everyday Life by Marguerite Holloway

                      Scientific American, April, 1996

On this morning, Seattle's sky and surrounding waters are gray, and even the
blue eyes and sweater of Margie Profet seem gray. The evolutionary biologist
is explaining that she loves the rain and its flat tones because they make
the world look more three-dimensional, and she points to her panoramic view
of Portage Bay and the University of Washington to demonstrate: "That glass
one over there is my building, the astronomy building."

It is true that a planet that may support life has just been found, but it
seems a little premature for an evolutionary biologist to be turning to
astronomy. Profet, however, says she is just doing what she has always done:
trying to come at a subject that she doesn't know so she can get excited and
perhaps find a different perspective "I just wanted a new adventure in life,
and I wanted back that math part of my brain that had died."

Profet is also, at least for now, removing herself from a discipline that
she helped to popularize and from a storm of criticism over her recent book,
Protecting Your Baby-to-Be. Renowned for three evolutionary theories, Profet
appears to have crossed a line in the eyes of some of her colleagues in the
field of Darwinian medicine, and of many in the medical establishment, when
she recommended that pregnant women follow her advice: don't eat pungent
vegetables.

In pared-down form, her pregnancy theory posits that the nausea or food
aversions many women experience in the first trimester are adaptations
designed to protect embryos. Profet argues that some toxins in plants
including, for instance, allyl isothiocyanate, a carcinogen found in
cabbage, cauliflower and brussels sprouts evolved to ward off herbivores and
that some of these compounds could, even in tiny amounts, cause defects
during the critical stage when organs are forming. In general, the
Pleistocene plants that constituted the diet of our hunter-gatherer
ancestors and, hence, those that would have been the force behind the
adaptation were even more likely to contain toxins, Profet explains, because
agriculturists had not yet selectively bred for crops that were less bitter
(that is, less poisonous).

Therefore, her theory contends, we evolved mechanisms to deal with these
dietary threats. Hormonal changes make the olfactory systems of pregnant
women hypersensitive, able to detect spoilage or teratogens in a single
whiff. A woman can thus avoid dangerous foods, relying instead on nutrients
that her body stored up before conception. Once the embryonic organs are
more or less formed, hormones allow nausea to subside, and women can eat
less discriminatingly. Profet correlates the period of pregnancy sickness
(from about the third week after conception, when the placenta forms, to 14
weeks after conception ) with the period of organ creation. And although
there are no direct studies on the topic, Profet extensively reviews the
literature on plant toxins as well as on birth defects.

So, according to Profet, a pregnant woman fleeing the scene of boiling
broccoli or brewing coffee is protecting her embryo and should pay attention
to her instincts. Which is why Profet says she took her message out of the
realm of theoretical biology and academic papers to the realm of the masses
and national book tours. But her dietary proscriptions have brought her into
often rancorous conflict with obstetricians and nutritionists, as well as
with the March of Dimes. Her critics contend that she herself may very well
cause birth defects by warning women to stay away from greens.

Others embrace her theory if not her approach. "I was critical of the stance
that she has taken. But I was also very supportive of the idea, because I
think it is fascinating," says Cassandra E. Henderson of the Montefiore
Medical Center, who intends to study plant toxins and to determine whether
the compounds cause birth defects in animals. "But I cannot go to the next
step and say, 'Don't eat this because it may cause birth defects.' I have no
evidence."

=46or her part, Profet believes there is ample reason for concern. Even if
there are no direct data, she says that no one has come up with a criticism
that her theory cannot handle. She maintains that her goal was to get women
to "err on the side of caution until we have better information" and to
stimulate scientific study. "I like looking for solutions to things. And for
that you need good theory, and you need good experiments," Profet explains,
adding that doing these experiments is not where her talents lie. But she is
adamant to the point of self-righteousness about speaking out. "We are
talking about life and death. This is not some kind of intellectual fun, you
know," Profet states. "People are getting birth defects."

She pauses and rolls her hands up inside her sweater, taking in the room,
its wall of windows and wide vista, the binoculars on the table. A view of
the water is very important, Profet says, because she did her best thinking
in the mid-1980s in San Francisco, in a house with such a view. She had just
completed her second bachelor's degree this time in physics at the
University of California at Berkeley; she had studied political philosophy
at Harvard University for the first one and "I just wanted some time to
think about whatever I wanted to think about."

That happened to be evolutionary biology. "I mean, the first month out of
physics I went and got a standard biology book. I knew some people in
evolutionary biology, and I would have some conversations with them, and I
would read everything, and I just started thinking about things. I had this
wonderful view and my animals," recalls Profet in her fast and breathless
voice, holding out pictures of wild foxes and the raccoon she befriended
while living there. "And it was really productive. It was the most
productive time of my life, the next three or four years."

Her pregnancy theory, which she first began to research in 1986, was
followed in quick succession by two others that are essentially variations
on the same theme: ejection. The second one came to her one night when her
allergies had suddenly brought on a fit of scratching, and she began to
think about people who had fits of coughing and sneezing. "I thought: What
do you need these things for? It is almost like you are trying to expel
something immediately.

And, well, maybe you are trying to expel it immediately, and if so, what
would cause that?" Out of this came her idea that certain forms of allergies
evolved as a means of expelling nasty things such as plant toxins and insect
venom.

"Every mechanism out there was designed by natural selection to solve a
problem, so you have to identify the problem," Profet declares. You have to
ask, "During the Pleistocene, would this really have been adaptive?" This
reasoning led her next to an explanation of menstruation. She recalls that
when she first heard about pregnancy sickness and menstruation as a kid,
neither made sense: "I was miffed. No, not miffed. Just puzzled." Then one
night in 1988, she dreamed of black triangles embedded in a red background
(other aspects of the dream resembled an educational cartoon about
menstruation that Profet had seen in high school); her cat woke her up in
the middle of the vision, so she was able to remember it. It became clear to
Profet that menstruation is more than merely a monthly waste of blood and
energy: the process allows the reproductive tract to rid itself of pathogens
that attach themselves to sperm.

According to her argument, the myriad bacteria that are found in and around
the genitals of men and women hitch rides on sperm, thereby gaining access
to the uterus and fallopian tubes. The uterine wall sheds each month so it
can cleanse the system, washing away the contaminants that could cause
infection or infertility. As with the theory of pregnancy sickness, the
menstruation idea awaits further study but Profet specifically urges that
gynecologists check women with particularly heavy flows to see if they have
active infections. She is again outspoken about being proactive: "You get
bad theories that people adhere to, and it is killing people or causing them
a lot of harm." In the scientific community, debate continues.

In an upcoming issue of the Quarterly Review of Biology Beverly I.
Strassmann of the University of Michigan argues, among other things, that
there is no evidence that there are more pathogens in the uterus before
menstruation than there are immediately after. Strassmann offers instead
another explanation for such bleeding: the uterine lining sloughs off when
implantation does not occur, because keeping the womb in a constant state of
readiness requires more energy than do the cycles of menstruation and
renewal.

Despite her rich intellectual life between 1985 and 1988, when she worked
out her theoretical trinity, Profet says her poor economic situation drove
her to consider getting a doctorate in anthropology at Harvard she figured
that with a stipend and a student's schedule she could do the coursework and
keep researching evolutionary biology. "But it was just not like that at
all," she says. Graduate school was too stifling for Profet's taste and, she
maintains almost wistfully, the wrong place for people who need freedom and
who want to use the energy of their twenties and thirties to ask naive
questions: "You may be using up a time in life that will just never come
again."

She left the program, returning to California and to a part-time job that
she had held in the Berkeley laboratory of Bruce Ames, a toxicologist famous
for his work on plant toxins and natu- ral carcinogens. (She still maintains
an affiliation with the lab.) Over time, her ideas two of them published in
the Quarterly Review of Biology and one as a chapter in the 1992 book The
Adapted Mind - earned Profet a reputation as a maverick. And in 1993 she won
one of the "genius" awards from the MacArthur Foundation.

But Profet seems tired of evolutionary biology for now. "I love the field as
I think the field should be," she says in a nearly questioning voice. "But
as the field currently is, I don't." Profet says too few of her colleagues
make a distinction between a hypothesis and a theory, rushing to publish
ideas that are not rigorously worked out but that may have implications for
public health. And so she says it suits her just fine to be a visiting
scholar in astronomy. "I am here to explore," Profet says. "I think it is
good to try to jump into something new every once in a while." As long as
her room has a view.

Internet Source:

http://darwin.clas.virginia.edu/~rjh9u/profet2.html

Kirt Nieft / Melisa Secola
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