1 How Many Sexes Are There

Genesis Story Is BAD BIOLOGY and Causes Too Much Suffering! Muslim Adam & Eve

“ The Narratives of Our Culture Are Too Limited”

“… perhaps it is the religious grounding of our culture that makes us think there are only two types of bodies to begin with

The implicit dimorphism of the story of Adam and Eve deeply conditions our understanding of the possibilities of our species

… it is not that their (transsexual children's) bodies or minds are "wrong," but that the narratives of our culture are too limited for their bodies, their minds, and indeed, even their fantasies”

Conroy, Melissa. (Assistant Professor of Religion in the Department of Religion and Philosophy at Muskingum College, New Concord, Ohio - Remarks after hearing NPR program on transsexual children) Trangenderism And Religious Narratives. SIGHTINGS, (6/5/2008)

How Many Sexes Are There?

Human Chromosomes 23 Pairs XX (Female), XY (Male) Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Genetic Sex Determination

Typical male has Y chromosome

Typical female does not have Y chromosome

Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Y Chromosome Has Testis-determining Region (Gene)

Is a sex-determining gene on the Y chromosome in placental mammals and marsupials

Initiates male sex determination

Located near tip of short arm of Y chromosome

Codes for SRY protein

SRY = Sex-determining region Y

aka testis determining factor = TDF

Causes gonad to differentiate into testes

SRY protein is DNA-binding regulatory protein

Acts as transcription factor

Initiates transcription of cascade of genes necessary for testicular differentiation

Barr Body in Typical Female Cells Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Sexual Differentiation of Internal Genitalia Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Sexual Differentiation of External Genitalia Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Sexual Development in Mammals Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Puberty Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Male Testosterone Levels Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005)

Puberty Alteration in typical women Ganong, William F. REVIEW OF MEDICAL PHYSIOLOGY 22 nd ed. Lange Medical Books/McGraw-Hill (2005) Female Secondary Sex Characteristic Cause Genitalia Enlargement of breasts, uterus, vagina Estrogen Voice larynx retains prepubertal proportions; high-pitched voice Lack of testicular androgens Hair less body hair, more scalp hair, flat-topped pubic hair pattern Lack of testicular androgens Pubic and axillary hair Androgen Mental Interest in sex Androgen Body Conformation Narrow shoulders, broad hips, thighs that converge, arms that diverge (wide carrying angle), female distribution of fat in breasts & buttocks Lack of testicular androgens Skin Sebaceous glands more fluid (inhibit acne) Estrogen

There Is Only One Sex!

Mammalian body plan is inherently female

Male is altered female !!!

Every individual’s body plan is a variation on the female theme

Default (female)

Fully altered (male)

Partly altered (intersex)

Everyone falls on some point of the continuum from female (gynemorphic) to male (andromorphic)

This body plan is organized by presence or absence of steroid hormones during the critical period of development and then activated later by steroid hormones during puberty