After allowing his F1 crosses to self-pollinate, Mendel observed that

Explanation:

First-generation (F1) progeny only showed the dominant traits, but recessive traits reappeared in the self-pollinated second-generation (F2) plants in a 3:1 ratio of dominant to recessive traits. Mendel then crossed these pure-breeding lines of plants and recorded the traits of the hybrid progeny

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.