Just one letter this week—from Peter Klopfer, professor emeritus of biology at Duke, and Dr. Gerard Honoré—but it's an important one that deserves to be read in its entirety:
"Your admirable edition on HB 2 unfortunately missed an opportunity to clarify why, from a purely biological point of view, the law is as nonsensical as it is. The sex of a newly born infant has historically been based upon specific physical differences: a vagina or penis, ovaries or testis, and other, associated, structures. Not every individual necessarily possesses all of the attributes of one sex or the other, but, for the most part, the division into males and females has seemed unproblematic. Until recently ...
We now recognize that the physical differences are not dichotomous—a small penis may be indistinguishable from a large clitoris; a not-fully-fused scrotum can resemble partially fused labia. Even the chromosomes of an individual may not be solely XX or XY, but part of a mosaic, with some cells XX and others XY. More importantly, all of these markers that appear to define one's sex are not concordant: one can rank as a male according to some, or as female according to others. For example, an individual with organs that appeared at birth to be male (penis and scrotum) might later be found to possess ovaries and breasts. Birth certificates, which are based on genital structure alone, are inevitably flawed.
In short, from a biological point of view, it is not just that there is a continuum from characteristics that are clearly male-like to those that are clearly female-like, but that these continua exist in a multidimensional space. It is, in some respects, analogous to a situation found in the protozoan, paramecium, which, rather than having two sexes, has multiple "mating types," with some restrictions as to which types can actually mate.
The varieties of biological sex are certainly greater than two. One supposes that there are limits and that there may be reasons why certain possibilities or combinations thereof are not possible, as with paramecium.
The visible horizons of our scientific, social, and humanistic knowledge regarding what was once believed to be a very simple scenario—assignment of sex and gender—have expanded rapidly in the past fifty years. We now consider a thrilling and uncharted frontier for further understanding the possibilities of human sex and gender, where uncertainties are multitudinous and absolute rules seem to be few. The tantalizing prospect of new knowledge to be gained can be shared alike by scientists and poets, psychologists and playwrights, as well as all of humankind—is there anyone whose life could not be touched by this?"