Monday, August 3, 2009

Parthogenesis, Gynogenesis, Hybridogenesis

Someone on OYT described an almost 3-inch long wasp that he encountered in the middle of the night. He swung a broom at the thing, fell off balance when it charged his face, and cut a big gash in his hand on a vent cover.

Another poster kindly provided a picture of a 1.5-inch long wasp from Kansas that he found dead in his basement. He remarked that huge wasps do not scare him (because he always finds them dead) but house centipedes freak him out.

I had no idea what a house centipede was so I used mankind's latest, greatest inventions: Google and Wikipedia. While reading about centipedes, I came across the term parthenogenesis. Parthenogenesis is a form of asexual reproduction where an egg cell develops into a fully grown organism without fertilization. It comes from the Greek parthenos (virgin) and genesis (creation). Parthenogenesis does not (necessarily) create clones because it is an egg cell that matures and egg cells are products of meiosis, a process that includes crossing over between chromosomes. For species like humans, with an XY sex determination, all parthenogens are female (because the mother only has XX to give to the child).

Two relations of parthenogenesis are gynogenesis and hybridogenesis. Gynogenesis is akin to parthogenesis but requires the presence of sperm from a closely-related species for the oocyte to develop. The sperm does not contribute any genetic material to the oocyte and so all gynogens are also female.

Hybridogenesis is not asexual but hemiclonal. The female mates with a male in the usual fashion and father and mother each contribute one set of chromosomes to the child. However, in hybridogenesis, when a female child matures and produces her own oocytes, only her mother's chromosomes are passed on; the father's genetic material is excluded from her gametes. In this way, the female line continually passes down the same genetic material while each individual female possesses novel genetic material from a male donor. It produces a distinct and powerful hereditary factor with respect to the progenitor female's chromosomes while allowing for individual hybrid vigor from the male's contribution. No mention was made of the male hybridogen's gametes but one assumes, from the silence, that they reproduce as normal (their gametes are varied by crossing over during meiosis and randomly assigning either mother's or father's chromosome to each).

Parthogenesis, gynogenesis and hybridogenesis have some potential for a magical society of women who have lasted through the ages. Perhaps a goddess served as the founding matriarch of the family and all of her daughters through the ages share her genetic legacy. With an isolated society like Wonder Woman's Themescarra, parthenogenesis would allow them to reproduce without any contact with mankind.

With a gynogenetic society, women would have to enter the world to find appropriate mates (perhaps, due to magic, each woman's mate must be discovered in a sort of 'one true love' or 'Mr. Right' kind of way, though owing more to genetics and magical arbitration than romantic feelings (unless one wanted those too)). Or a sister society of normal men and women develops as servants to the goddess's descendants with suitable men being plucked from them to mate (perhaps a reward for heroics or exceptional service or maybe chosen like racehorses for genetic worth; this might lead to resentment on the part of the lesser, normal women who keep losing their best men and sons to the goddess's daughters). This latter idea would not be a fateful Mr. Right situation but a "closely related species" kind of mating, perhaps evoking a sense of Jack Kirby's New Gods.

A hybridogenetic society would be less fantastic and more subtle than the other two. It could play into a prophecy where the party has to find a descendant of the goddess to prevent some disaster (since each of her daughters would have her DNA unsullied by mortal man).

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