As an atheist and a trained sociologist, I fail to see any evidence for innate human rights (what some may call natural rights). While I personally agree that all humans should be extended equal rights and that this should occur in all places and at all times. Yet, at the moment there is no evidence that such origins of such rights are to be found in either biology or human nature (if there is such a thing).
This is why I was disappointed to hear human rights being discussed in the atheist community as something that is concrete, either through biology or human nature.
The most annoying thing was the lack of understanding that such claims are a form of ethnocentrism, the idea that one culture is superior to another. Tied to this was a critique of cultural relativism, which is never a justification of violence or discrimination. Rather it is a method, in social science, that attempts to avoid ethnocentrism. It does not say that all cultures are equal or all things in them equally true, only that the people in such cultures believe their cultural beliefs to be true (sometimes universally true). This is exactly what we are doing, if we lay claim to innate/biologically determined human rights: we are claiming that our beliefs are superior to those who do not believe in innate human rights.
It is a minor point, but one that I find many atheists and humanists misunderstand (including thinkers as great as Sam Harris). To make claim to innate human rights is to condemn all those who break them to being less than human. That is not something that a humanist, in my opinion, should be dong.
Happy to discuss.