Answer:
oh my yikes, thats tuff..
Explanation:
This is beneficial and is actually an adaptation of humans to climates with larger amounts of sunshine. The darker color of skin helps prevent damage such as sun burn.
Bio-geographic isolation is the separation of part/a whole species due to either biological or geographical reasons.
Biological could be lack of food, or a more preferable source of food somewhere else, etc. Geographical could be rivers, oceans, mountains, etc.
The answer is Klinefelter syndrome.
Nondisjunction disorders are conditions resulting from an unbalanced distribution of chromosomes. In the case of Klinefelter syndrome, the sex chromosomes are affected. Rather than having an XX for female or an XY for male people with Klinefelters have either XXY or XYY.