Fascinating new info…
Hominins suffered lead poisoning starting at least 2 million years ago – Ars Technica:
Lead exposure sounds like a modern problem, at least if you define “modern” the way a paleoanthropologist might: a time that started a few thousand years ago with ancient Roman silver smelting and lead pipes. According to a recent study, however, lead is a much more ancient nemesis, one that predates not just the Romans but the existence of our genus Homo. Paleoanthropologist Renaud Joannes-Boyau of Australia’s Southern Cross University and his colleagues found evidence of exposure to dangerous amounts of lead in the teeth of fossil apes and hominins dating back almost 2 million years. And somewhat controversially, they suggest that the toxic element’s pervasiveness may have helped shape our evolutionary history…
…But perhaps its most interesting feature is that modern humans have a version of the gene that differs by a single amino acid from the version found in all other primates, including our closest relatives, the Denisovans and Neanderthals. This raises the prospect that the difference is significant from an evolutionary perspective. Altering the mouse version so that it is identical to the one found in modern humans does alter the vocal behavior of these mice.