The longstanding puzzle of a gigantic evolutionary line has been solved more than 160 years after the boundary was first drawn up. The confusing line, which is both imaginary and real, arose millions of years ago after a continental collision triggered extreme climate change that impacted the species on each side of the divide in different ways, a new study reveals.
The boundary, known as the Wallace Line or Wallace's Line, is a biogeographical barrier first mapped out in 1863 by British naturalist and explorer Alfred Russel Wallace, who famously proposed the theory of evolution by natural selection at the same time as Charles Darwin.
