A species of “walking” fish is helping shed light on how humans evolved to stand upright millions of years ago. The sea robin, a bony fish that lives at the bottom of the ocean, has six leg-like structures that it uses to scurry across the sea floor, and sometimes dig for prey. Researchers have now discovered that sea robins grow their legs using the same genes that also play a role in the development of human limbs. The team said its findings, published in two separate papers in the journal Current Biology, could help shed light on how humans evolved to walk upright some six million years ago.