"What we have learned about genes has allowed us to understand that we are not so much things merely existing in the world as beings in constant interaction with the world. If you took this idea to an extreme and imagined that you grew up on another planet, the essentially dynamic nature of animal building by genes and environment might mean you'd look very different. Cloned plants that have exactly the same genome can look like very different specimens if planted at different altitudes. In the same way, if you had grown up on a planet with lower gravity or one that was more distant from the sun and had a lower oxygen concentration, you might be incredibly tall, or short, or weedy, or blind...or maybe you'd have a supersized brain. If you took your African ape genome and cultured it on yet another planet, maybe the resulting you would have translucent skin. The point is that although we experience ourselves in some sense as finished or perfected, we are not in any way intended. There is no blueprint for what humans are meant to be. And as this moment is merely one moment in the past and future history of our evolutionary lineage, your life right now is merely an instant in the past and future history of the interaction between your genome and your environment."

-- Christine Kenneally, The First Word - The Search for the Origins of Language, p 197