Because improbable complexity is the hallmark of selection, organisms are the most improbably complex—that is, the least entropic—known things in the universe. Entropy is the degree of disorder in a physical system, and tends to increase in all such systems (that’s a basic law of physics known as the second law of thermodynamics). Entropy’s tendency to increase is the reason why, as Yeats said, “things fall apart”: your new car or new suit, for example, tends to get more beat up rather than more pristine as times goes by. Because adaptations generated by natural selection are extraordinarily complex, they have extraordinarily low entropy, and selection is in fact the most powerful natural anti-entropic process known to science.

Biological natural selection explains how adaptations can have purpose (again, in the sense of function; for example, the purpose/function of an eye is to see), and why organisms can behave purposefully. It does not explain, however, how life in general could have any transcendent purpose, above and beyond the genetically-encoded interests of organisms themselves. That would require a higher-order explanation, and the Complexity paper presents what I regard as the most promising alternative of this sort. It’s an idea based on Lee Smolin’s theory of cosmological natural selection, which he first proposed in 1992 and presented most fully in his book The Life of the Cosmos.