Around 200,000 years back, Sapiens evolved in Africa. Then around 60,000 years back they left East Africa towards the Arabian Peninsula and from there to India following, maybe a coastal route. This is what the Out of Africa theory says. When these sapiens reached Europe, they met other species such as Neanderthals and Denisovans and interbred with them. The other species died out and now we are the only homo species that remain. At least, that’s what we believed so far.
There not even a slender certainty that it is true. Sapien remains have been found at multiple sites in China that have been dated to between 70,000 and 120,000 years ago. Additional finds indicate that modern humans reached Southeast Asia and Australia prior to 60,000 years ago. This predates the time span normally attributed to the Out of Africa theory, implying that there were previous migrations from 120,000 years back. Here is the interesting data point: all of us — all non-Africans — are descendants of a single ancestral population dating back to 60, 000 years. This implies that the migrations prior to 60, 000 years, was probably a tiny population. Even though they were not that large, they left markers around the world for us to discover. Later a major migration occurred, leading to all of us.
It’s fancy to believe in a simple West to East migration in a linear time frame. Unfortunately, nature behaves differently. Human migration requires complicated models.
The second interesting data point comes from a discovery from a butchered rhino at Kalinga in the Philippines. The bone bed where this rhino met its grim death had 57 stone tools and was dated to between 777 – 631 thousand years before present. This pushes the date of appearance of hominins in the Philippines by hundreds of thousands of years. It is a big discovery. Of course, these were not sapiens, but Homo erectus. It seems there were no land bridges to the Philippines during that time and the only way these hominins could have reached there would have been by deliberately constructing rafts. Think about it, around 700, 000 years, our ancestors built rafts and crossed channels that were 10 KM wide.