What would cause a fully functional true hermaphroditic human

[lodlock]

I have been trying to research this for a short story I am writing but to no avail. What karyotype, SRY mutation, or other genetic mutation would be required to produce a true hermaphroditic human that has both fully functional sexual organs?

[overtone]

Have you read the stories of Ursula Leguin? iirc "The Left Hand of Darkness" is the longest one based among such humans.

 

She attributes the physical setup to - probably - genetic engineering by the founding civilization; and then ignores the physical nature of it.

[RyGuyFly]

The closest thing I can think of would be a somesort of "intersex" individual or a sexual/genetic chimera or mosaic. Basically its when an individual is made up of two different sets of cells with different dna. Sometimes one set will be male and one set female. If you look up these terms you'll see that it's complicated and the extent of the gender mixing / blending varies from individual to individual.

 

Now with this type of condition it's possible for people to have mixed or ambiguous genitalia internally and externally. technically it maybe possible for an individual to have a uterus and produce both sperm and eggs. I have never heard of anyone "self-fertilizing" but technically it could be possible if the individual was mostly female with functional uterus etc but had one ovary that produced functional eggs and one that produced functional sperm. Idk if this would fall under true hermaphrodite or not. Also the resulting offspring would probably not be hermaphrodites. Genetically they would be like the incestuous offspring of two siblings.

 

Note: I just remembered you said it was for a short story. I have some other ideas depending on the nature of the hermaphrodites in your story. Like do they reproduce sexually or asexually? Some real life animal hermaphrodites are asexual and "self-fertilize". Others have intercourse to reproduce but the animals have both male and female parts. Yet others might change sex depending on the need of the population.

 

Just my thoughts.

Edited September 7, 2015 by RyGuyFly

[GreenMan]

I think the main problem even if such human would exist is functionality of sex organs.It's almost guaranteed that one of the reproductive organs,testes or ovaries would not function,because both organs have very different hormone requirements to work properly and produce eggs/sperm.For example if you continuously inject a male with a coctail of female hormones (estrogen),achieveing the same hormonal composition as in an avarage female,the male reproductive system would be suppressed(Which is exactly what happens in sex change hormone therapies).

I imagine in a human hermaphrodite which produces all the hormones needed for both female and male sex organs would just end up having both ovaries and testes that don't really do anything.So it's far more complicated than anyone could guess,it would probably requre many genetic changes,and not just on sex chromosomes.

[RyGuyFly]

I thought of that too greenman. But I was also thinking that if they are writing a scifi story then the science doesn't have to be exact or real. its scifi after all. It just needs to sound convincing enough. but on the other hand...man... when movies are obviously scientifically uncreditable or unfeasible I feel they lose big points in my book.

[lodlock]

Thank you for your insights.

 

Given the hormonal requirements for functional reproductive organs that could lead to a potential problem. The fact that we typically go through hormonal cycles to begin with could hold some form of answer. Possibly if the cycles were prolonged and interchanging. Perhaps a quarterly or semi-annually change between male and female hormones unless said person has become impregnated.

 

The design here is not to have asexual reproduction but to have a race where gender has evolved to essentially become irrelevant when it comes to reproduction. Asexual reproduction would not work as it loses the biological aspect of a newly combined DNA sequence. I could come up with some reason why it would work but I would prefer to theorize things which are possible. I find it detestable when people take the "because I said so" approach.

 

Thank you all for your ideas,

 

-Lodlock