If we are "mythbusting", lets start with the myth that everyone sprang from the crack middle of Africa. Can you prove that myth in any manner?
Apologies for another side-talk. The curious might appreciate it. Otherwise, ignore it.
I cannot prove anything to you or to anyone else. There is no need for that and prehistoric science does not work like that. It's not physics experiment. It's way more complex, messy and requires a lot of research and thinking in multiple fields. It's really hard. I can try to encourage you to explore available evidence critically, on your own, have open mind and ask questions. I could give you reliable pieces of information upon which known evidence is assessed and complex jigsaw puzzle is put together. The emerging picture, or narrative, is far from perfect, it is not simple either, but we are working hard on it to perfect it.
1.
DNA sequencing around the world currently indicates when, where and how up to ~60,000 years ago. We are getting better at exploring this avenue of origin with every year. Beyond ~60,000 years it's currently messy in terms of details of migrations and inter-breading. Still, DNA gives us good, more general trends up to 2-3 millions years ago. Here is one interesting article that explores this messiness and level of certainty. Have a look.
2. Geographical distribution and migrations is as complex too. Apart from DNA analysis, we have both rich and patchy fossil records scattered around the planet, depending on how detailed story we want to tell. We use Carbon C-14 dating for backtracking events by estimating how old bones are. The confidence level of such measurements is ~70% upwards on smaller time scales, up to ~50,000 years back, and less further down the past. Here is another account on early migrations, with some certainties and uncertainties.
Why humans left their African homeland 80,000 years ago to colonize the world
www.smithsonianmag.com
In terms of big movements of land mass that you mentioned, "lost continent" between Africa and India, it is estimated that it had happened ~85 million years ago, before dinosaurs were extinct, some ~65 million years ago, and before more complex mammals evolved. Here is some insight.
https://www.newscientist.com/article/2119963-long-lost-continent-found-submerged-deep-under-indian-ocean/
If you are familiar with evolutionary biology and animal tree, you will appreciate the following timeline, to give it some perspective:
- the landmass that submerged occurred when simple mammalian species lived, rodents, mice, etc.
- many million years had to pass for more complex mammals to evolve, such as primates (lemurs, etc.), the oldest fossil of which is estimated to be ~47 million years old. This very fossil was famously exhibited around the world's natural history museums a few years ago.
- so called Great Apes family (gorillas, us, orangutans) evolved from primates
- early Hominids split from other Great Apes 7-9 million years ago, which is way before our species, Homo sapiens, evolved on the planet, some ~200,000 years ago, in Africa.
- Aboriginal Australians arrived on the continent 45-55,000 years ago in normal migration fashion, from south each Asia.
Once this occurred, Yamaha finally figured out that Homo enjoys tribal sound of drums and gave us independent bass channels.
