In humans gene flow usually comes about through the actual migration of human populations, either voluntary or forced. Although gene flow does not change allele frequencies for a species as a whole, it can alter allele frequencies in local populations.
Hopefully this helps.
Because some scientist might see something that other scientist do not. good luck.
Not a lot besides the fact that they are both mixtures in water, because a solution is a mixture in which the solutes ( solids) dissolve, and suspension is a mixture in which the solutes don't dissolve.
