The physical impossibility of Noah's Ark

It was a mighty ark. 140 metres long according to the Bible. However most scientists agree that still would not have been enough to hold the millions of species that have been discovered on earth.

As next week's meeting of the UN Convention on Biological Diversity gets ready to kick off in Bonn, Germany, estimates of the number of species on earth are surging to hull-busting levels as biologists find new life almost everywhere they look, from African swamps to Antarctica.

The ever-widening menagerie is a paradox when an expanding human population, pollution and climate change threaten what United Nations' studies say is the worst spate of extinctions since the dinosaurs were wiped out 65 million years ago.

Government officials trying to protect the modern world's wildlife gather in Bonn from May 19-30 to examine progress towards a goal set in 2002 of slowing biodiversity loss by 2010.

Most experts say the target is slipping out of reach.

Even so, wider research means finds of new species such as a legless lizard in Brazil or a Tanzanian shrew are testing biblical scholars' calculations on how Noah squeezed all animals aboard the Ark.

'It's of course physically impossible,' James Edwards, executive director of the Encyclopedia of Life, said of the biblical account.

The Encylopedia is cataloguing all identified species, 1.8 million so far, in a free online service.