What does a determinist think of evolution?

Question

If you believe in evolution, you believe in random genetic mutation. If you believe in hard determinism, you believe that nothing is random.

Answer 1

I'm not a determinist, but I can answer anyway. Determinism and evolution are perfectly compatible. The "random genetic mutations" you refer to are "random" only in the way that rolling dice or shuffling cards is random. These are macro-level phenomena that cannot be predicted because you would need to know the details of all of the fundamental elements and forces at work in order to predict the outcome, and realistically there is no way that we will ever have the technical ability to gather that much information about any complex system. (And, in addition, quantum mechanical uncertainty adds another, deeper meaning to the word "random".) But a determinist would say that IF you could somehow know all of the details, then you could predict the outcome with certainty. In other words, the determinist would say that there ARE detailed facts of the matter, even if we can never know these details ourselves. The sort of "randomness" implied by the theory of evolution is only this epistemological sort of randomness; it does not require the ontological sort of randomness implied by quantum mechanics.

Now if you were to ask "What does a determinist think of quantum mechanics?" then you would be focusing upon a real problem. Albert Einstein was a determinist. He believed that the indeterminism of quantum mechanics was evidence that the theoretical framework of quantum mechanics was incomplete. He thought there were hidden variables that the theory just was not able to identify. In other words, he would say that there ARE detailed facts of the matter, but they are hidden from us due to limitations in quantum theory. Quantum theory, in contrast, says that there simply are no facts of the matter. There is simply no fact of the matter whether an electron is or is not located in a certain region of space. There are only probabilities, and these probabilities are part of the way things actually are – not just ignorance on our part. As a determinist, Einstein could not accept quantum mechanics, but he would not have seen any incompatibility between his belief in determinism, and the theory of evolution because the term "randomness" in the theory of evolution does not refer to the sort of fundamental randomness found in quantum mechanics. The randomness in evolution is simply like shuffling a deck of cards in order to mix things up.

Answer 2

Although it would seem that in principle, given positions and momenta of all particles, that one could calculate the development of the universe thereafter, in practice it is impossible, and would be in any event due to Heisenberg's uncertainty principle. So strict determinism is out, and truly random effects (as, for example, radioactive decay) are in. Evolution is now a proven fact.