Mankind is already adapting to the widespread impacts of future climate change - but how did we do it in the past?

Otago University researchers, along with colleagues from the Max Planck Institute for the Science of Human History and the University of Oxford, have gazed thousands of years back into the past to shed light on past human responses to climate change.

It has been argued that some of the earliest human experiments with agriculture worldwide were linked to a changing climate, so the research team studied archaeological deposits at a site in the rainforests of the New Guinea Highlands, in the same ecology where some of the earliest global agricultural behaviours have been documented at the Unesco site of Kuk Swamp.

The researchers analysed the carbon and oxygen isotope in the teeth of 140 small mammals from the site with the aim of producing an environmental record directly reflecting human behaviour in this region.

The team found that the zone where tropical forest and open ecosystems met provided a stable source of subsistence for human hunter-gathers, who continued to hunt bats, cuscus, and possums from 12,000 to 300 years ago, indicating that agriculture was not an inevitable or forced event in this part of the world.

Tropical forests have been frequently perceived as unviable habitats for long-term human forager and agriculturalist occupation and subsistence.

A long period of work in New Guinea has helped to overturn this perception in the anthropological and archaeological literature.

Humans are now known to have occupied areas of this region, covered today in montane rainforest, from 45,000 years ago and some of the earliest evidence for human experiments with agriculture comes from the tropical forested portions of New Guinea.