In August 1991 newspaper headlines around the world announced an amazing discovery: a difference in the brains of heterosexuals and homosexuals. In 1993 American scientists claimed they had discovered a gay gene. Sexual orientation, it now seems, is not a choice, not a disease nor a faddish whim, but a fundamental biological part of who we are.Chandler Burr's ground-breaking work is the first and only comprehensive look at this revolutionary new science, biology on the farthest edges of current scientific practice. A Separate Creation: How Biology Makes Us Gay takes us into laboratories where researchers are using incredible technologies to discover what makes us straight or gay. From studies of male rats that ovulate and a species of African animal in which the female has a penis, to the political fire-storm surrounding the claim of a gay gene, from a new silicon chip made of human DNA that could discern the sexual orientation of the foetus in a woman's womb, to a working theory that homosexuality is a genetic/bacterial condition that could be 'cured' with an antibiotic, Burr explores this fascinating and often ethically ambiguous territory with clarity and an objective eye.