In either case, the first settlement would have occurred during an era of lowered sea levels, when there were more-coextensive land bridges between Asia and Australia. Watercraft must have been used for some passages, however, such as those between Bali and Lombok and between Timorand Greater Australia, because they entail distances greater than 120 miles (200 km). This is the earliest confirmed seafaring in the world. By about 35,000 years ago all of the continent had been occupied, including the southwest and southeast corners (Tasmania became an island when sea levels rose sometime between 13,500 and 8,000 years ago, thus isolating Aboriginal people who lived there from the mainland) as well as the highlands of the island of New Guinea. Archaeological evidence suggests that occupation of the interior of Australia by Aboriginal peoples during the harsh climatic regime of the last glacial maximum (between 30,000 and 18,000 years ago) was highly dynamic, and all arid landscapes were permanently occupied only roughly 10,000 years ago.

The dingo, a type of wild dog, appeared in Australia only 5,000 to 3,000 years ago, which postdates the time that Aboriginal people began hafting small stone implements into composite tools some 8,000 years ago. Whereas the dingo was introduced from Southeast Asia, the small implements appear to be independent inventions from within Australia. Within the past 1,500–3,000 years, other important changes occurred at the general continental level: population increases, the exploitation of new habitats, more efficient resource exploitation, and an increase in the exchange of valued items over wide areas.

There is evidence for complex social behaviours much earlier, however, including cremation before 40,000 years ago, personal ornamentation (shell beads) by 30,000 years ago, and long-distance trade in objects before 10,000 years ago. It has not yet been ascertained whether there were single or multiple waves of migration into Australia, although recent genetic evidence indicates multiple donor groups, whether from a single heterogeneous migration or multiple waves. While there is no doubt that only anatomically modern humans (Homo sapiens sapiens) have ever occupied Australia, skulls found in the southeast suggest to some the existence of two distinct physical types. However, most now accept that there was a wide range of variation in pre-European populations. It has also been argued that one group on the Murray River practiced a form of cosmetic cranial deformation that led to their different appearance. Some have posited that Aboriginal cultures have one of the longest deep-time chronologies of any groups on Earth.

More than 200 different Aboriginal languages were spoken (and hundreds of dialects; see alsoAustralian Aboriginal languages), and most Aboriginal people were bilingual or multilingual. Both languages (or dialects) and groups of people were associated with stretches of territory. The largest entities recognized by the people were language-named groups, sometimes referred to by Europeans as “tribes.” There may have been as many as 500 such named, territorially anchored groups. Their members shared cultural features and interacted more with one another than with members of different groups. These groups were not, however, political or economic entities, and, while language names may have been commonly used by groups as labels for one another, individual and group identity was grounded in much more locally oriented affiliations and memberships. There was no consciousness of a shared national identity. However, the worldview of Aboriginal peoples tended to be expansive, with a perception of society as a community of common understandings and behaviours shared well beyond the confines of the local group.

According to traditional scholarship, Aboriginal people were hunter-gatherers who grew no crops and did not domesticate animals (apart from the dingo), so they were directly dependent on their natural environment. On the other hand, some historians and archaeologists in the 21st century argued that Aboriginal people employed agricultural practices that were far too sophisticated to be characterized as hunting and gathering. Nevertheless, the conventional interpretation holds that the Aboriginal people, though nomadic, had a very strong sense of attachment to sites and areas in their home territory, where most of their hunting and gathering was done. The need to balance population with resources meant that most of the time people were dispersed into small food-gathering groups. But several times a year, when food resources permitted, large gatherings would be organized, and much of the social and religious business of the society would be transacted over a two- to three-week period of intense social activity. This rhythm of aggregation and dispersal was fundamental, but over much of this dry continent ecological factors made dispersal the predominant fact of life.

As Aboriginal people understand it, the Dreaming beings retained control of all power and fertility, which they would release automatically into the human realm as long as humans followed their blueprint; this included the regular performance of rituals to ensure a continued flow of life-giving power. Spirit beings were used as messengers to communicate with the living and to introduce new knowledge into human society. Through dreams and other states of altered consciousness, the living could come into contact with the spiritual realm and gain strength from it. Diversefeatures of the landscape provided tangible proofs of the reality and world-creating powers of the Dreaming beings, and a rich complex of myths, dances, rituals, and objects bound the human, spiritual, and physical realms together into a single cosmic order. Despite the uncertainties involved in getting a living, Aboriginal people had a strong sense of self and a religious confidence in their ability to cope with and control their physical and social world.