Lost World of the Australoids

Since the Last Glacial Maximum (LGM) which was around 20,000 years ago, and definitely since the end of the Last Glacial Period (LGP) which lasted from circa 115,000-11,700 years ago, the world has changed a lot.  The ice sheets retreated causing general warming, and the sea levels rose dramatically.  Many areas that were once covered in ice sheets or its climate was extremely cold, were now much more warmer allowing for the growth of several flora and fauna.  

In my opinion, since the most recent Out of Africa migration which supposedly occurred around 50,000 years ago, this intrepid group migrated eastward and took the Southern Route to India and eventually into Southeast Asia, East Asia, Siberia, Oceania, and beyond.  They would of course meet up with other hominins and interbreed with them.  But because the climate during those early years was very cold in higher or lower latitudes, it was more conducive for human populations to thrive in the equatorial regions (or nearby it) and especially near the seas.  Much of North Africa and the Middle East were undergoing desertification, but much of India, Southeast Asia, Oceania, and Southern China were warm or even hot, and were close to the seas, with perhaps several rivers and lakes on land thus allowing access to the nutrients from the sea, rivers, and lakes, and that's everything from fish, whales, mollusks, crustaceans, algae, seaweed, etc.  In my opinion, much of the human population was centered in this area of the world due to the very fortunate biome that existed there.  Not only was this a warm biome that was next to the sea and contained rivers and lakes, but it was abundant in nutritious flora, i.e., fruits, vegetables, spices, and etc., and fauna also, such as wild fowls (ancestor of the domesticated chicken, ducks), wild pigs, goats, deer, and several bovids.  Many of the lands especially the islands that form the Ring of Fire were fertile due to the volcanic activity.  There was also plenty of rain.  It was a good place to be a human being if one knew how to take advantage of it.  I believe the Australoids, who by the way form a common ancestor with Mongoloids and Caucasoids, did take full advantage of their environment, and their populations were probably much larger especially before 20,000 years ago than in colder regions of the north.  This is of course just an opinion, because I haven't rigorously proven that, but it's very likely true.  If we look at Gunung Padang, and if dates of 20,000 year before the present are true for the early stages of its construction, then ancient Australoids were indeed very advanced and sophisticated possibly creating the world's first cement, coins, and earliest large structures such as pyramids.  Australoid genes have been proven to arrive in the Americas separately and perhaps earlier than the majority of Native Americans today who are mostly of Proto-Mongoloid and Proto-Caucasoid stock (please correct me if I'm wrong), therefore, they were able to migrate far and wide very early in history.  We as humans have to look beyond the veil of known history which was taught to us in school, in media, etc. We have to accept that there was a world that was likely advanced and sophisticated and that existed before 5,000 years ago which is usually the oldest age limit of ancient history, and is mostly lost to us and uncredited.  This very old world would of course crash (undergo a civilization collapse or collapses) due to the dramatic climate changes of the past 20,000 years since the LGM.  It would be unfair to blame everything on climate change, but climate change was a big factor in their demise.  All I ask is that we have to keep an open mind to the world that once was, and that world will likely reveal a lot of surprises, and even knowledge and technology that we are not even aware of or invented ourselves.