Based on this analogy I suggest, further, that even the first great leap forward was made possible largely by imitation and emulation. Wallace's question was perfectly sensible; it is very puzzling how a set of extraordinary abilities seemed to emerge "out of the blue". But his solution was wrong...the apparently sudden emergence of things like art or sophisticated tools was not because of God or "divine intervention". I would argue instead that just as a single invention (or two) by Galileo and Gutenberg quickly spread and transformed the surface of the globe (although there was no preceding genetic change), inventions like fire, tailored clothes, "symmetrical tools", and art, etc. may have fortuitously emerged in a single place and then spread very quickly. Such inventions may have been made by earlier hominids too (even chimps and orangs are remarkably inventive...who knows how inventive Homo Erectus or Neandertals were) but early hominids simply may not have had an advanced enough mirror neuron system to allow a rapid transmission and dissemination of ideas. So the ideas quickly drop out of the "meme pool". This system of cells, once it became sophisticated enough to be harnessed for "training" in tool use and for reading other hominids minds, may have played the same pivotal role in the emergence of human consciousness (and replacement of Neandertals by Homo Sapiens) as the asteroid impact did in the triumph of mammals over reptiles.

So it makes no more sense to ask "Why did sophisticated tool use and art emerge only 40,000 years ago even though the brain had all the required latent ability 100,000 years earlier?" — than to ask "Why did space travel occur only a few decades ago, even though our brains were preadapted for space travel at least as far back Cro Magnons?". The question ignores the important role of contingency or plain old luck in human evolutionary history.

Thus I regard Rizzolati's discovery — and my purely speculative conjectures on their key role in our evolution — as the most important unreported story of the last decade.