saved even more energy: How much brain did we gain from a smaller gut? Nobody really knows for sure, but it’s significant. An exhaustive overview is available in Leslie C. Aiello, “Brains and Guts in Human Evolution: The Expensive Tissue Hypothesis,” Mar. 1997, http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84551997000100023.
