from the PDF:
[snip] Our results showed that the Australasian genetic signal, previously described as exclusive to Amazonian groups, was also identified in the Pacific coastal population, pointing to a more widespread signal distribution within South America, and possibly implicating an ancient contact between Pacific and Amazonian dwellers... This genetic evidence for the presence of Y ancestry on the South American Pacific coast indicates that this ancestry likely reached this region through the Pacific coastal route, and therefore could explain absence of this genetic component in the populations of North and Central America studied so far. [/snip]
Earlier threads:
The new face of South American people [Luzia not African or Australasian]
https://www.freerepublic.com/focus/chat/3761442/posts
LUZIA - Second Oldest Human Skeleton Ever Found In The Americas
https://www.freerepublic.com/focus/news/1283339/posts
I do like that Pacific coastal route theory. Humans have been traveling by boat since very ancient times.