How old do paleontologist believe the earth is?

Scientists now know the Earth is actually 4.54 billion years old, an age built on many lines of evidence from the geologic record.

Explanation:

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)

prism b but im not for sure