Denisova DNA

The graphic above is interesting. It shows the world location of of people with Denisova alleles. Interbreeding with Denisova individuals took place much earlier than movement into the Americas.  

The people of Oceania have the most genetic evidence of interbreeding with Denisovians.  The people of Oceania have the most genetic material from Desinova.

But look at the concentration in the north part of South America. The map looks like a migration by sea from Oceania. The alternative explanation is that the migration came from Siberia over the land bridge but let little trace in North Asia and North America. Rather unlikely.