Human evolution may be quite different to what we know it now that a new bone has been found that is 400,000 years earlier than the oldest human bone found. The bone may give scientists the answers to the missing link they have been seeking regarding the shift of humans from when they walked bent over to when they started to walk upright.

The discovery of the bone, 250 miles from Addis Ababa, is important because it now appears that the earliest upright humans go back to 2.8 million years rather than 2.3 million years.

The bone fragments found by an Ethiopian student of Arizona State University and an accompanying research team were from the lower jawbone of homo lineage. The findings support the notion that this may be a unique species.