The Doors of Eden / Adrian Tchaikovsky
I expect this of Tchaikovsky by now, but no one condenses centuries of hypothetical evolutionary development like this guy. Interspersed with totally plausible and yet very different ways life could have evolved and thrived (or not) on Earth, we follow some really well-crafted characters through events that get really strange. Really ambitious book, great journey, though the ending felt weak and didn’t quite live up to the development.