Homo erectus had an amazing range, both spacial and temporal. It inhabited the whole of the Africa-Eurasia landmass, and did so for over a million years (from 1

Homo erectus had an amazing range, both spacial and temporal. It inhabited the whole of the Africa-Eurasia landmass, and did so for over a million years (from 1.8Mya to 800kya). It is no surprise we're finding evidence of island populations that managed to survive even later (such as Flores). As for the later stages,: Sapiens or proto-Sapiens interbred with Neanderthals even earlier than the widely accepted cca 40kya admixture date; somewhere between 430kya and 270kya Sapiens dna enters Neandertal genome. While most of it was eventually bred out, mtDNA remained and all later Neandertal populations carried Sapiens mtDNA, with their original mtDNA disappearing The reason for noncongruent out of Africa migration dates is that at least two occurred; other than the generally accepted cca 70kya migration, there was an earlier one which was limited to coastal areas of Arab peninsula, Indian subcontinent and SE Asia until it reached the previously unpopulated area behind the Wallace line, where it resulted in PNG and Australian aboriginal populations. The reason for coastal-only migration until PNG was that those areas were already inhabited by Neanderthals and Denisovans whom Sapiens was unable to outcompete. Only after Toba eruption (75kya) do those populations become weakened enough for Sapiens to outcompete them and that's when we see first successful migration to Middle East.