How does amoeba engulf food particle

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.