How did the appearance of photosynthetic organisms affect the evolution of life on earth?

Photosynthetic cyanobacteria reengineered the planet. Photosynthesis led to two more singularities - plants and animals appeared. Atmospheric oxygen resulted from a change to a microbe's metabolism that evolved once, at a specific time in the earth's history

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)