In scripture, the word generation is from a word that means a group of people all from the same kin. The Greek word “genos” is where we get our English word genetic and race. When scripture mentions generations, it is talking about a single related people.
The Greek word for nation is “ethnos”. It is where we get our word ethnic. In scripture it is a people who are kin, that is, of the same race.
The word for Adam is a description of a white man with rosy cheeks, one who can blush. The distortion comes from churches teaching that Adam and Eve were the parents of all men of all races. This ignores the meaning of the word Adam and the focus and continuity of scripture.
Context really is the key to understanding the meaning and intent of scripture. It is often ignored in order to teach a universal religion that is not found in scripture.