So without mentioning what the evidence is about 190K years ago, from two points we infer that they were there the whole intervening time? If conditions were harsh, and if we know they eventually got at least as far as SE Asia, why would we not think that in the huge span between those points, they might have wandered away and later returned? 160k years is a long long time. Apparently humans came across the land bridge into the Americas like 16k years ago.