A Niggardly Cartoon
There is a very good cartoon here about use of the word "niggardly". See here and here for examples of the uproar that use of the word "niggardly" has produced in the past. Despite appearances, "niggardly" has nothing whatever to do with the famous "N word".
The DNA of Race
There is no topic on which Americans are more tongue-tied than race. Even mentioning the word is almost taboo. About the only thing you can safely say on the subject is the monotonous Leftist chant that "race does not exist". Yet Americans not only notice racial differences but they respond very strongly to them -- as the "white flight" phenomenon shows.
So in such circumstances it is perhaps encouraging that some geneticists (many of whom seem to be Asian) are resolute enough to continue their studies of the matter. And what they find is that the different races (which Leftists assure us are all "a social contruct") are genetically very distinct. You can predict from a person's DNA which "social" race he belongs to -- and you can predict it with a very high probability of getting the prediction right.
The Abstract (scientific summary) of the latest research report is here and you can find some interpretative commentary from an anthropologist here