January 19th, 2012 by Alexandra Jacoby
I read a blog post about a paper (that I have not read). The post is “Why do women menstruate?“ by PZ Myers, a biologist and associate professor at the University of Minnesota, Morris, blogging at Pharyngula. The paper is “The evolution of menstruation: A new model for genetic assimilation: Explaining molecular origins of maternal responses to fetal invasiveness.” by Emera D, Romero R, Wagner G.
I’m not a scientist and don’t routinely have access to papers like these. Usually, by the time ideas raised in them reach me, they would be solid-feeling facts, authoritative and done — not inspiring questions and wonderings that I can pursue in my way.
They might be about the products that were developed in response to, or as a side-effect of the research, or maybe I’d hear about newly discovered dangers to my health.
Rarely, do I get to be in on the “why.” To think about the story of it–my body–alongside the scientists when they are exploring what might be the origin of, or deciding factors in, why we are the way we are. As human bodies.
(So, thank you, internet. Thank you, bloggers).
“The anatomy of the human gravid uterus exhibited in figures” by William Hunter, Public domain.
This paper (as I understand it via the Pharyngula post) focuses on the conflicting interests of the relationship between a fetus and the woman carrying it: the fetus acting for its survival and development, and the woman as agent for her life, health, and the ability, should she want to, to carry more pregnancies to term.
The research notes a difference among mammals who spontaneously initiate the process of building up the uterine lining, regardless of whether there’s an implanted embryo (like us, with our monthly-ish menstrual cycles) and those who build up the lining only when triggered by an embryo, and asks why do we do this? Why not wait until you need it?
The answer seems to be because you won’t be ready if you wait. Maybe it’s like having guests over last-minute. You might have food and drink enough for all, but you might not. And, you might have stuff laying around that is more personal than you want guests to see. Or, maybe it’s all fine enough. Last-minute is frequently doable, but it’s better to be prepared. Prepared gives you options. Prepared gives you a chance to make it really comfortable and welcoming. Prepared sets you up to have the experience you wanted to have.
Women menstruate to be body-ready to handle the situation of pregnancy in the context of their whole lives, and their family’s whole life.
The monthly preparation of the uterine lining establishes optimal conditions for the relationship, the active give-and-take, between woman and fetus. And, while there are conflicting interests in this shared space of blood and nutrients, I see it as like any relationship between any things living — on a continuum of interaction between self-expressing creatures, cells or trees. There are intricate, elegant processes taking place to make it all happen. There is preparation and desire on both parts — blood, nutrients, and soil, air and water being exchanged and used up among us. There are points of contact, expected and understood, or surprising, or painful, or deadly. We’re in it together for better or worse. All of our relationships are active. Everything is interrelated and contingent and based on routines and cycles. On those we build, change, evolve…
I think only we are impatient about it — want it done faster, with less work and no mess. The stuff of life is messy, though.