Franz Boas — American Scientist born on July 09, 1858, died on December 22, 1942

Franz Uri Boas was a German-American anthropologist and a pioneer of modern anthropology who has been called the "Father of American Anthropology"... (wikipedia)

We do not discuss the anatomical, physiological, and mental characteristics of man considered as an individual; but we are interested in the diversity of these traits in groups of men found in different geographical areas and in different social classes.
Remember that in every single case in history the process of adaptation has been one of exceeding slowness. Do not look for the impossible, but do not let your path deviate from the quiet and steadfast insistence on full opportunities for your powers.
I hope I may have succeeded in presenting to you, however imperfectly, the currents of thought due to the work of the immortal Darwin which have helped to make anthropology what it is at the present time.
If we were to select the most intelligent, imaginative, energetic, and emotionally stable third of mankind, all races would be present.
Furthermore, the study of the present surroundings is insufficient: the history of the people, the influence of the regions through which it has passed on its migrations, and the people with whom it came into contact, must be considered.