those who can adapt the most to their environment , survives ..
those who cant get instinct...
black people are exposed more to sunlight so their skin no longer create melanin..
the white ones in europe , has more melanine.. cus theres almost no sunlight..
for es..
in 100 ofspring of spiders
20 of them have poison , 20 can jump , 20 have long legs.. the rest are normal - 40..
there are always slight mutation in every generation , but it takes millions of years..
the rest are normal - 40..
more likely those who lack traits get instinct..
the rest flourish and they devide in their own in the evolution three..