Many ideas in Replay Earth stem from asking what it is that evolution has built for us from our mammalian past. Thinking of humans as animals is always tricky business — we have so many biases and prejudices that meet at that intersection. Nonetheless, we are mammals and we do retain many characteristics of them.

Here’s the ones that intrigued me, and that I wanted to play with in the novel:

1. We are social animals. Most mammals live in a web of families, bands and herds. From what I know of anthropology, prior to the advent of civilization based on formal agriculture about 10,000 years ago, we lived in small groups of dozens, perhaps associated in larger groups of maybe 200. There’s also evidence that in the last 80,000 years or so, maybe multiple such groups in a region might meet up a few times a year to trade and perhaps dance, sing and mate.
2. We, like other mammals, balance competition and collaboration. Our society is highly competitive and that tends to make us look back at see that we were always competitive and emphasize that part of our selves. But we also have always been collaborative, and many anthropologists point to that as equally, or more, responsible for our long-term survival and emergence as one of the planet’s dominant life forms.
3. We think of ourselves as “conscious beings” but like all mammals, we have a powerful set of instinctive responses. Some are learned in childhood, some by experience, and perhaps some are also innate. We have only recently begun to understand that these responses — instinct, the unconscious, subconscious, call it what you will — are not always reined in or controlled by our rational mind. We’re still working all that out, eh?

I continue to read and learn about all of this. Advances in genetics, imaging and so on are helping to clarify the neural picture. Nascent fields like behavioral economics are chipping away at what it means in practice. All good stuff — but I think we are so far away from any firm understanding of how all of that plays out that imagination is entirely called for at this point.