Earlier this year, a team of Australian researchers published new findings about a fragment of a ground-edge axe discovered in the Kimberly region of Australia. The flake had been excavated in the early 1990s but hadn't been discovered among the rest of the excavated material until 2014.
     Between 44,000 and 49,000 years old, it is the earliest evidence of ground-edge axe technology anywhere in the world, closely coinciding with the first arrival of modern humans on the continent, which archaeological evidence suggests occurred between 60,000 and 50,000 years ago. According to the research, the fragment represents the independent invention of this technology by the first Australians. The process involves grinding and abrading the stone - uncommon outside of the region until around 10,000 years ago, and unique within it.
     To understand its significance we need to look at underlying assumptions about where and when human complexity developed and what form it took. 'Human complexity' generally refers to the range of behaviors that help define what it is to be "human" - for example the development of increasingly sophisticated tools and social structures.
     Historically, archaeological evidence from Australia and most of Southeast Asia has not aligned well with conceptual models of the development of human complexity based almost exclusively on the archaeological records of Europe and Africa.
     There is continued unease with the early stone artifact record from Australia, the simplicity of which is often still construed as evidence of a deficiency in early Australian cultures. The ground-edge axe flake discovered in the Kimberley region challenges these assumptions.
     The fragment fits into a growing body of evidence including that of rock art in Sulawesi, Indonesia, and highly skilled deep-sea fishing off the coast of East Timor demonstrating that the first colonizers of Australia and Southeast Asia were developing expressions of human flexibility and creativity earlier than previously assumed. The archaeological evidence from this region also shows expressions of complex human behaviors that are unique for the time period.

Edited from Sapiens (13 September 2016)