Fossil teeth reveal how brains developed in utero over millions of years of human evolution

Fossilized bones help tell the story of what human beings and our predecessors were doing hundreds of thousands of years ago. But how can you learn about important parts of our ancestors’ life cycle – like pregnancy or gestation – that leave no obvious trace in the fossil record?

The large brains, relative to overall body size, that are a defining characteristic of our species make pregnancy and gestation particularly interesting to paleoanthropologists like meHomo sapiens’ big skulls contribute to our difficult labor and delivery. But the big brains inside are what let our species really take off.

My colleagues and I especially wanted to know how fast our ancestors’ brains grew before birth. Was it comparable to fetal brain growth today? Investigating when prenatal growth and pregnancy became humanlike can help reveal when and how our ancestors’ brains became more like ours than like our ape relatives’.

(click the link at right to read the entire article in The Conversation written by WWU's Tesla Monson)

Thursday, January 26, 2023