This book arose out of pure curiosity of where it might take me. I also wanted to write down a number of ideas that I have been thinking about for many years as well as some more recent ones. The bottom line of the ideas focuses on the origin and timing of the first people to enter Australia. The subject now, however, is infinitely more complex than it used to be because it seems the more we learn about the process the less we know. The subject leads into the origin of modern humans; what happened to more archaic humans in our region, the abilities of early humans like Homo erectus and how large the world's population was by the late Pleistocene. Indeed, how did humanity grow, where were the main growth centres and what were the characteristics and outcome of that growth? I have come to accept, however, that in this business for every question answered two more appear.

There are some accepted norms regarding Pleistocene palaeodemography that require challenge. So I have tried to challenge them and put forward some conclusions that to some may seem eccentric. The main object is to open all doors; put up the challenges, have a fresh look at the evidence before us and propose some what ifs. Perhaps the most interesting thing about archaeology is that is constantly surprises. Our ideas about the past are constantly challenged or turned on their heads.