I'm not aware of any point in history where a cadre of biologists engaged in genocide. It seem like the norm under the banner of religion.
I wonder how "Social Darwinism" acquired such a negative connotation, if not for the Nazis?
Alas, I bet you knew that but just wanted to distract us for a moment.
Consider the words of Viktor Frankl, psychologist who was imprisoned at Auschwitz:
"If we present man with a concept of man that is not true, we may well corrupt him. When we present him as automation of reflexes, as a mind machine, as a bundle of instincts, as a pawn of drives and reactions, as a mere product of instincts, heredity and environment, we feed the despair to which man is in any case already prone. I became acquainted with the last stages of corruption in my second concentration camp in Auschwitz. The gas chambers of Auschwitz were the ultimate consequence of the theory that man is nothing but the product of heredity and environment--or, as the Nazi liked to say, of Blood and Soil. I am absolutely convinced that the gas chambers of Auschwitz, Treblinka, and Maidanek were ultimately prepared not in some Ministry or other in Berlin, but rather at the desks and in the lecture halls of nihilistic scientists and philosophers"