From the comments:
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Hi AC
If you look at the sea level depth between the top of Australia and PNG you will see that there was a land
bridge between the two and that this was open until about 18,000 years back when the great melt started after
the ice age.
During the period in which water was tied up in massive ice fields the oceans were up to 130 metres lower than now.
Oceans reached a temporary high about 7,000 years back at the peak of the melt.
KK
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Google: ancient gold mines in Africa. Evidence of a large civilisation dating 150,000 to 250,000 years ago in Africa which had cities and farms and extensive gold mines. Stanford University California and Cambridge University UK studies revealed that Eve was the first mother with modern humans aquiring her genes 143,000 years ago, Adam who gave males the Y chromosome did so 60,000 years ago,84,000 years apart. We know very little of ancient Earth times and civilisations.