Short answers, pulled from the story.
François Bernier published the text titled Nouvelle division de la terre par les différents espèces ou races qui l'habitant in 1684. This work marked one of the first post-Graeco-Roman attempts to classify humans into distinct groups based on physical appearance.
Statistical analysis shows that an average of 85 percent of statistical genetic variation exists within local populations. Only approximately 7 percent occurs between local populations within the same continent and roughly 8 percent occurs between large groups living on different continents.
In Brazil, racial identity was never governed by rigid descent rules like the one-drop rule used in the United States. A Brazilian child was never automatically identified with the racial type of one or both parents, and full siblings could pertain to different racial groups based on their appearance.
The National Academies of Sciences Engineering and Medicine formally declared in March 2023 that researchers should not use race as a proxy for describing human genetic variation. Their report titled Using Population Descriptors in Genetics and Genomics Research states that race is a socially constructed designation.
Each category was assigned specific behavioral traits that reflected the prejudices of the time when European powers were expanding their colonial empires across the globe. The Atlantic slave trade created a powerful economic incentive to categorize human groups in ways that justified subordination.