Of course, there are minor differences between various ethnic groups

This is a poor choice of words, which undermines the author's thesis. If there were actually distinct "ethnic groups" then one could call those groups distinct "races." The point is that when we classify people (into ethnic groups, or races), the specific criteria we use, and the boundaries we draw, are subjective.

This is only true if you have an understanding of genetics grounded in scientifically verifiable physical reality.

"Don’t you see that the whole aim of Newspeak is to narrow the range of thought? In the end we shall make thoughtcrime literally impossible, because there will be no words in which to express it."