How can polymorphism's become a dominant trait in a population, w/o selective pressure being present?

[Elite Engineer]

Just a curious thought if a random polymorphism could ever become a dominant trait in a population without any kind of selective pressure on the gene.

 

~EE

[CharonY]

I assume you used the term "dominant" in a different context than in the genetic sense? I.e. do you mean frequency rather than the effect on phenotype?

[Elite Engineer]

I assume you used the term "dominant" in a different context than in the genetic sense? I.e. do you mean frequency rather than the effect on phenotype?

Yes, my bad. I meant frequency.

[CharonY]

You can have stochastic effects, mainly genetic drift and mutations affecting allele frequencies.

[Itoero]

Just a curious thought if a random polymorphism could ever become a dominant trait in a population without any kind of selective pressure on the gene.

 

~EE

Can you give an (theoretical) example?

There is always selective pressure.

Edited September 27, 2016 by Itoero