The more turbulence, the better the degree of dispersion.
2.
Some localized lateral dispersion takes place during cortical column development in the mouse, but the degree of dispersion is molecularly regulated and indeed could vary across species.
3.
The degree of dispersion of the melanin, which is in subcellular bundles called melanosomes, has some influence on the observed color, but melanosomes in the iris of humans and other vertebrates are not mobile, and the degree of pigment dispersion cannot be reversed.