Colorblindness is a recessive sex-linked trait. ... Remember that in incomplete dominance, the two traits blend together; in co-dominance, the two traits are equally expressed; and in sex-linked traits, the traits can be dominant or recessive, but they always appear on the X-chromosome.
Color blindness is a sex related trait in which 99 percent of the people have a different visionary of red-green color. Most of the men are color blind and it has been seen that a very less number of women are found color blind if compared with men.
Whereas if the female is a carrier and the male is not affected the there are chances that the child born is suffering from color blindness.
This is a sex linked trait and X chromosome is usually carried from a mother to the son. So, the probability of the male being affected is more as compared to female.
I would say disruptive selection, because the sudden eruption of the volcano disrupted the circumstances of the lizards, allowing the black ones to survive better because of camouflage against the black rock.
