Who observed that organisms in a population differ slightly from each other in form, function and behavior?

mendel's first law states that during the formation of reproductive cells , pairs of hereditary factors for a specific trait separate so that offspring receive one factor from each parent.

explanation:

this website is for anybody really not just for girls just saying, also while a lot of males are mean and you know there are the few who are kind and then there's the nice-guys but then theirs also guys like me who are shy we don't get out much because there are people like you who exist who would most likely punch a guy in the face so next time just think about things before you post them to a website where guys and girls can see your question.