The Bible was written by a woman. Not all of it, just the good bits. Those fantastic old stories, like Adam and Eve in the Garden of Eden, were written by a woman living in Jerusalem 3,000 years ago as works of literature, only later co-opted to the service of religious dogma. So argues Harold Bloom in his treatise on the bible as literature, The Book of J.

Bloom places the mysterious "J author" at the pinnacle of the literary canon alongside Homer and Shakespeare. Seen through the ironic female gaze, God becomes less the ultimate patriarch than a petulant child sulking and raging his way through history. The Bible, with its cornucopia of talking snakes, burning bushes, seven-headed dragons, apocalyptic floods, parting seas, epic battles, tribal sagas, prophecies, miracles and magic is arguably the greatest fantasy story ever written. So if this most timeworn of texts was written by a woman, where in God's name are the women in today's modern myth-making?

Everywhere, actually. Science fiction – our modern version of those ancient mythic stories – was invented by Mary Wollstonecraft Shelley in Frankenstein; or, A Modern Prometheus. In recent decades much of the best SF writing has come from women writers, from Margaret Atwood's The Handmaid's Tale and Doris Lessing's Shikasta to Mary Doria Russell's The Sparrow and The Time Traveler's Wife by Audrey Niffeneger, with hundreds more catalogued at the excellent SF Mistressworks.

But a genre that women have done so much to shape seems to have been co-opted by men. Of 29 Grandmasters of Science Fiction, only four are women – Connie Willis, Ursula Le Guin, Anne McCaffrey and Andre Norton. This year the two major UK awards for science fiction – the Arthur C Clarke and the BSFA – both announced all-male (and also all white and rather elderly) shortlists. Women, we were told by the Clarke judges, were simply writing fantasy, not science fiction.

Julie Crisp of Tor books – one of the UK's leading SF imprints – added to the discussion recently with a data-driven blogpost that seemed to shift the responsibility back to women writers. Of 502 manuscripts submitted to Tor, only 32% were from women, and those which were submitted were predominantly fantasy – either epic or urban – not science fiction.

Encoded in to the this strange divide between fantasy and science fiction is what Joanna Russ, author of The Female Man, called The Double Standard of Content. How To Suppress Women's Writing, Russ's satirical text on sexism in art, is 30 years old this year but its lessons are still largely unlearned. Women's writing is dismissed as fantasy, while the fantasies of men are granted some higher status as science fiction.

All women SF writers have to do, they are repeatedly told, is conform to this double standard to be accepted. But no artist worth their salt artist willingly kowtows to the arbitrary, self-serving rules of petty cliques. Many women writers are, quite rightly, looking at the encoded sexism of the SF genre and taking their creativity elsewhere.

In her Guest of Honour speech at the Continuum convention NK Jemisin, one of the rising stars of contemporary SF, reiterated that the problems of both sexism and racism are not just about the 10% who are actively bigoted, but the larger group who empower racism and sexism through silence. Too many fans and professionals in SF and geek culture stay silent in the face of implicit racism and sexism.

The consequences are that talented women writers like Tricia Sullivan struggle to get published, while mediocre male writers continue their careers because we carry on buying their books. We demand a Doctor Who that isn't a White British Male, but continue to laud the television show when we are ignored. Our cinema screens are cursed with a summer of Batman, Superman, Iron Man and X-Men, and we queue up to watch these adolescent male power fantasies without questioning. Why is the white male the only genetic blueprint worthy of heroic status?

There's a huge audience of people who love science fiction, but do not see themselves reflected in white male faces that dominate it today. And there's a growing cohort of talented writers creating great literature for those people, as some time spent reading the groundbreaking Strange Horizons demonstrates. In these chaotic times for the industry, it's the publisher brave enough to break from the discriminatory definition of science fiction and reshape the genre around this untapped audience who will prosper. As will the writers who stop reinforcing the inherited prejudices of a patriarchal genre, and instead tell stories that help meet NK Jemisin's challenge to make SF a "literature of the world's imagination."