Researchers have used distinct markers from human subpopulations to trace back to our common African root in a giant human "tree." However, a “trellis” model might be more appropriate.

This week, meet a big-brained ancient human relative, hear a meteorite as it lands on Earth, spot a tiny kangaroo-like marsupial, and more.

If you imagine the human body as a wiring diagram ... But our history goes deeper still: we have an entire branch of the tree of life inside of us — our inner fish is only one stopping point.