And yet in two million years, the human brain has nearly tripled in mass, going from the one-and-a-quarter pound brain of our ancestor here, Habilis, to the almost three-pound meatloaf that everybody here has between their ears.
在两百万年中， 大脑脑容量从我们祖先能人的1.25磅， 增大了近三倍成了现在的3磅。