DWARVES!

[Zarnaxus]

I am studying genetics in school right now, and my teacher told me that dwarfism is actually a dominant trait, but since people with dwarfism didn't survive in the early ages, the trait is not present in the gene pool.

 

so i looked it up...

 

Achondroplasia, the gene disorder associated with dwarfism is an autosomal dominant genetic disorder. Now I got to thinking...

 

If people with dwarfism who are achondroplastic survive much more often today than they had in the early days, will the dominant trait start to take over? ...after maybe ten thousand years of civilization?

 

Dwarves will take over the world... O.o

[Blahah]

No, because homozygous children (those whose parents are both dwarves) do not survive more than a few days, so the trait is deleterious. Heterozygous children (with one dwarf parent or as a result of a novel mutation) with achondroplasia have a high risk of developing spinal abnormalities leading to paralysis, so infant mortality is much higher among dwarves than in the general population.

 

Because two dwarves cannot usually have children who survive to procreate themselves, the trait could never come to dominate our species. At most you could get 50% of the population being dwarves but in reality, some non-dwarves would always be mating with other non-dwarves and the dwarf population would drop rapidly.

 

Also achondroplasia can be detected early in pregnancy, and the option to terminate is offered in countries where abortion is permitted. Stillbirths are much more likely, as are other health complications leading to death in very early life.

 

Add to all that the fact that dwarfism conveys no evolutionary benefit, and you have a strong case that dwarves will never be more than a small minority.