700,000,000 years ago to 300,000 years ago: all of nervous system life gets by on "pattern detection" and "curve fitting" (Judea Pearl's term for deep learning).

Homo neanderthalesis or thereabouts to modern day: language, reason, cause and effect.

> Today’s dominant approach to A.I. has not worked out.

But "curve fitting" biological neural networks needed 2500 times more architectural exploration and enhancement to get to rudimentary language capacity than rudimentary language architectures needed to achieve all of human knowledge. That suggests we're doing the right thing in growing and enhancing deep neural network architectures now. Evolution suggests the next step to language and reason on the right architecture is comparatively easy.