US-Biologists to HHS: No Scientific Basis to Define Gender as Binary Trait

The Society for the Study of Evolution (SSE), the American Society of Naturalists (ASN), and the Society of Systematic Biologists (SSB) have sent a letter to the Secretary of Health and Human Services Alex Azar expressing concerns about the Department’s attempt to claim that there is a biological basis to defining gender as a strictly binary trait determined by genitalia at birth.  SSE, ASN, and SSB are member societies of the American Institute of Biological Sciences (AIBS). 
The letter is in response to a recent Department of Health and Human Services (HHS) memo obtained by the New York Times.  The memo proposes that the federal government legally define both gender and sex as “either male or female, unchangeable, and determined by the genitals that a person is born with.”  HHS argues that government agencies need to adopt a uniform definition of gender as determined “on a biological basis that is clear, grounded in science, objective and administrable.”
The letter from the biological societies reads in part, “Variation in biological sex and in gendered expression has been well documented in many species, including humans, through hundreds of scientific articles.  Such variation is observed at both the genetic level and at the individual level (including hormone levels, secondary sexual characteristics, as well as genital morphology).  Moreover, models predict that variation should exist within the categories that HHS proposes as “male” and “female”, indicating that sex should be more accurately viewed as a continuum.”

Read the letter here: http://www.evolutionsociety.org/news/display/2018/10/30/letter-re-scientific-understanding-of-sex-and-gender/