"We think plate tectonics may have been really important for life on Earth, for the evolution of complex life on Earth. It turns out, and this is the next generation where we’re going with the understanding the evolution of planets and life. It turns out that you actually have to think hard about the planetary context for life. You can just be like, “Oh, there’s a warm pond,” and then some interesting chemistry happens in the warm pond. You actually have to think about the planet as a whole and what it’s gone through in order to really understand whether a planet is a good place for life or not."

"Yeah. Because it’s really what about, thinking about complex systems? A space habitat would have to be as robust as an ecosystem. As the kind of thing, you go out and you see a pond with all the different webs of interactions. That’s why I always think that if this process of going out into space will help us with climate change and with thinking about making a long-term sustainable version of human civilization. Because you really have to think about these webs, the complexity of these webs and recognize the biosphere has been doing this forever. The biosphere knows how to do this."

"But what we actually found was that none of those are actually hard. The whole idea of hard steps, that there are hard steps, is actually suspect. What’s amazing about this model is it shows how important it is to actually work with people who are in the field. Brandon Carter was a brilliant physicist, the guy who came up with this. And then lots of physicists and astrophysicists like me have used this. But the people who actually study evolution and the planet were never involved."