Tiny creatures

Scientists claim to have found the smallest form of life

 
Published: Tuesday 15 February 2000

Australian scientists say that they have discovered the smallest form of life, apparently far smaller than any known bacterium. Called nanobes, because their size is in the realm of nanometres (or one billionth of a metre), they are 20 to 150 nanometres in length and are smaller than cells.

Scientists at the University of Queensland in Australia discovered the tiny oddities four years ago in ancient sandstones retrieved from an oil drilling site some five kilometres below the Western Australian seabed. Made public for the first time in late 1998, the fuzzy tangles of filaments resembling fungi appear to reproduce quickly, forming dense colonies of tendrils. Laboratory analysis found signs of deoxyribonucleic acid ( dna ), the master molecule of heredity and life.

"Our recent work provides further evidence that the tangles are, in fact, alive," said Philippa J R Uwins, a scientist at the University of Queensland's centre for Microscopy and Microanalysis, who led the research.

So far, the main findings are that the colonies grow spontaneously, contain dna , are rich in biological elements like carbon, oxygen and nitrogen, and when cut in two show distinct outer and inner layers, including a possible nuclear area that holds dna .

But some experts remain sceptical. Norman R Pace, a microbiologist at the University of Colorado says that the nanobes were highly unlikely to be alive. "Their lower size limit of 20 nanometres is about the width of 10 dna molecules, making them too small to support all the other needed cellular machinery," he says.

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