Living paint

Microbes like red cyanobacteria and black fungus with yellow fruiting bodies have kept Australia’s rock art fresh for 40,000 years (Source: Bradshaw art.com)Rock paintings found in Western Australia’s Bradshaw region show traces of life.

Paleontologist Jack Pettigrew of University of Queensland and his team discovered that the art is resplendent with colourful bacteria and fungi, which constantly replenish the art’s colour. So they still look fresh after 40,000 years.

Pettigrew termed the phenomenon “living pigments”. This means pigmented microbes have supplanted the original paint of the art. This explains why attempts to date the art always produced inconsistent results.

His team speculates the bacteria and fungi survived through generations by cannibalising their predecessors and the original paint may have some nutrients that made this possible. He plans to sequence the microbes’ DNA to determine the age of the artefacts.