The following is an extract from an article first published in Agora magazine (HTAV).
It probably took around 4,000 years to settle the entire continent. The reptiles and megafauna were unlikely to have been the greatest danger. Instead, people had to learn which fruits were safe to eat, which plants were poisonous, which nuts or seeds could be processed, and which seasons were best for gathering root vegetables. The only way they could know this was to taste the food and wait to see what happened.
Once these risks were understood, Ancient Australians thrived. They became pioneers in science and technology, including aerodynamics  and astronomy . They formed complex, sophisticated societies with defined borders, laws and systems of governance that still exist today.
Life was not always easy, though. During the Pleistocene , water was scarce, so people stayed close to rivers, lakes and waterholes, and only travelled long distances if necessary. Hunting and gathering usually happened within a range. In drier areas with little water, this range was wide because people would have needed to travel far to hunt or find food. As the continent dried up, many people retreated to refuges. For those living in the arid zone, knowledge of water sources and how to reach them became crucial for survival.
One such water source is found at Koonalda Cave, located on the Nullarbor Plain. Since excavations began in the 1950s, archaeologists have found hearths that date to between 23,000 BP and 13,000 BP, which indicates that, even during the last glacial maximum , people were still travelling into the harsh and barren desert areas. Inside Koonalda Cave are two underground lakes, providing travellers with water as well as shelter . It also contains a good supply of flint, a type of stone used to make tools such as blades and scrapers. Some of the cave walls are so soft that they contain finger marks, called finger flutings, where people have scraped their hands along the rock. The marks were made around 20,000 BP and may be linked to initiation practices.
Towards the end of the Pleistocene, the climate and environment began to stabilise, producing warmer, wetter conditions similar to today. This period is known as the Holocene . During this time, global warming freed up waters that had been locked in the polar caps and ice sheets, and caused sea levels to rise. Lakes that had been dry for thousands of years now held water, and some even began to overflow. The arid zone shrank, allowing coastal and temperate regions to regenerate and thrive. Bass Strait flooded, isolating Tasmania from the mainland. The Arafura Plain that had joined Australia to Papua New Guinea vanished beneath the sea, forming the islands that lie in the Torres Strait.
During the last 10,500 years, Ancient Australia has undergone great changes, not only in climate, but also in technology. Across the continent, backed artefacts  enabled people to create more sophisticated and versatile tools. Needles and fishing hooks fashioned out of bone or shell became smaller and more refined. Stone drills and serrated saws began appearing in the Ancient Australian toolkit. Spears were embedded with stone blades and barbs, making them more deadly and effective.
People in Arnhem Land 9,000 BP stopped using boomerangs to hunt. Right along the coast, in places like the Whitsundays 8,000 BP, land hunters were forced to become expert fishermen as the sea levels rose. In Victoria and the Kimberley, the foundations for 5,000-year-old stone structures have been found. Instead of spears or hooks to catch fish in Northern Tasmania 4,000 BP, box traps and bone spikes were used. Earth mounds with stones packed on top were built on the volcanic plains of South Eastern Australia 3,000 BP and possibly used as raised bases for huts and gardens. In the last 2,000 years, fish and eel traps were built using stones in rivers and shallow ocean inlets.
Holocene technology was sophisticated and efficient, and became even more so once visitors from other continents began to make contact.
 Boomerangs were used in many cultures across the world, but the returning boomerang is unique to Australia. The oldest boomerangs in the world were found in Wyrie Swamp in South Australia. They date to 10,000 BP.
 Wurdi Youang stone arrangement near Geelong, dubbed ‘Australia’s Stonehenge’, seems to align with the equinoxes.
 The Pleistocene ranges from 2.5 million years ago until about 10,500 BP.
 The last glacial maximum (LGM) was the most intense cold period of the last glaciation, which peaked at around 20,000 BP.
 The second episode of the ABC’s First Footprints includes a segment about Koonalda Cave.
 The Holocene ranges from about 10,500 BP to today.
 A backed artefact is a stone tool that has retouch along one edge to make that edge blunt.