Find to bug the boffins

HEATED debate is expected at the world’s top geochemist conference in the US in August, as newly published Tasmanian research challenges long-held beliefs about how complex organisms, including animals and plants, came into existence.

Indrani Mukherjee said a discovery by her research team at the Centre for Ore Deposits and Earth Sciences (CODES) was demolishing long-held beliefs regarding the advance from primitive bacteria to multicellular organisms, which she argued took place between 1.8 billion and 800 million years ago.

Ms Mukherjee said her team’s theory — that a nutrient famine during that period, known as the boring billions, had caused bacteria to resort to desperate and innovative measures to survive, leading to more complex cells that eventually clumped together to form plants and animals — had not gone down well with most other geochemists.

She said she had struck fierce resistance from international peers while trying to get her team’s paper accepted by a publisher.

“There have been heated arguments and harsh reviews, I was going against the tide,’’ she said. “It wasn’t easy at all.” Ms Mukherjee said the doubters believed that the boring billions had been a time when evolution stalled due to a lack of oxygen, while her view was that bacteria did not need much oxygen, and that a scarcity of trace elements such as selenium, nickel and molybdenum — essential for life — had instead spurred evolution.

Both sides agree that it was not until a few hundred million years later that complex life started appearing, according to the fossil record.

Ms Mukherjee said she was braced for fierce debate as geochemists grappled with CODES’ new theory at the meeting in Boston.