For example, many consider objective morality (race based slavery is bad, say) to be a case for absolute good, which is hard to explain by pure randomness. I j

For example, many consider objective morality (race based slavery is bad, say) to be a case for absolute good, which is hard to explain by pure randomness. I just want to clarify some incredibly common misconceptions here. There are lots of claims on these issues, so it can be difficult to get a clear picture of which claims are actually supported by evidence. First, from an empirical perspective, all signs point to morality being an evolved phenomenon. This is studied scientifically by surveying different cultures, conducting game-like experiments, and testing for moral behavior in other species. You can find videos of monkeys who appear to have a sense of fairness, for example, and lots of other species (dogs, crows, other primates, etc.) all display varying levels of behaviors we call moral. This is what we would expect to find if these behaviors evolved as adaptations. Second, "randomness" is not an accurate word to use to describe evolution by natural selection. Mutations are mostly random, but those rare mutations that survive DNA repair mechanisms and produce a reproductive and survival advantage persist and spread. Something similar occurs with cultural memes, including those layers of morality which do not come from instinct. Finally, though you didn't mention this specifically, it's important to point out that scientists did not decide there was no God and then set out to prove it (a common misconception with some people I know). Most historical scientists were religious, but over time as more and more evidence was collected, scientists in aggregate found that what they had been taught about God was unnecessary for and often contradictory to their scientific discoveries. Thus, despite some scientists remaining religious, science itself is an atheistic process, as that is what has been proven to work. It's this track record of epistemological success that leads people to accept metaphysical materialism, not an a priori assumption. If you want more detailed summaries of the empirical support for these arguments, I recommend the book Why Evolution Is True by Jerry Coyne.