It wasn't that way during the Ice Age. There was a land area there (Sundaland) that was twice the size of present day India. Also, it was nice and warm and humans, of all sorts, must have thrived while the Neanderthals over in Europe were taking a 'beating'.
This thread may interest you.
I saw your other post (with the details) after I sent my previous reply, blam. VERY interesting stuff indeed.....