Earth 'depends on creepy-crawlies'

Nematode worms: Nature's unsung heroes

By Alex Kirby BBC News Online environment correspondent

Two leading British scientists are calling for a switch of research effort towards some of the Earth's smallest creatures.

They say we know far too little about most of the other species that share the planet with us.

It is humans' success, they argue, that threatens so many other species with oblivion.

Arguably it's the little things that run the world, things like soil microbes. They're the least-known species of all

Lord May

And the situation is so grave they believe we are approaching the Earth's sixth mass extinction.

The scientists are Lord May, president of the Royal Society (the UK's national academy of sciences), and Professor John Lawton, chief executive of the Natural Environment Research Council (Nerc).

Briefing journalists in London on the future for the Earth's biodiversity, both said the success of humans in dominating and populating the world left an increasingly small space for other species.

"The underlying cause of accelerated extinction rates is simply too many people," said Lord May.

Unnaturally rapid extinction

"Most conservation effort goes into birds and mammals - creatures like the panda, a dim, dead-end animal that was probably on the way out anyway.

"Yet arguably it's the little things that run the world, things like soil microbes. They're the least-known species of all - scientists like something sexier to work on.

We are losing species before we know they exist

"We don't know, possibly to a factor of 10, how many species there are on Earth. But if the better-known ones are reasonably typical, we're looking at an extinction rate a thousand times faster than in the fossil record - and it's accelerating.

"We know of about 1.7-1.8 million species - a tenth of the number of books in the US Library of Congress.

"Many of those are dead useless, but they all have a card index entry. We have nothing like that for the Earth's species, no global book of life.

"Yet we're burning the books in our biological library faster than we're able to read them."

Human exploitation of Earth

40% of all terrestrial plants

Up to 33% of all marine resources

60% of all readily available fresh water

Professor Lawton said: "The looming extinction crisis we face goes to the heart of the human enterprise.

"We are consuming about half of all the available resources on Earth, and the rate is growing exponentially - it's doubling every 30 to 50 years.

"It beggars belief that politicians don't realise this, though it's easy enough for them to identify al-Qaeda as a threat.

Mysterious planet

"We don't have inventories for creatures like nematode worms, tiny things about a millimetre long.

"They make nutrients available to plants, they make the soil work - and we don't know how many there are.

No global book of life exists

"We live on a little-known planet. Imagine being an astronomer without a star map."

Professor Lawton told BBC News Online: "Forget the charismatic mega-fauna. I'd like to see much more research going into things smaller than a millimetre.

"If I had my time again, I'd look at nematodes, soil micro-organisms and creepy-crawlies.

"They're the unsung heroes of the natural world, and we know next to nothing about them."

The bell tolls

The Royal Society has formed a working group to produce a strategy for identifying and conserving species and habitats.

The World Summit on Sustainable Development in Johannesburg last month agreed to work for a "significant" slowing of biodiversity loss by 2010. But the Society says there is no international consensus on how to measure progress towards the target.

Professor Peter Crane, of the Royal Botanic Gardens, Kew, chairs the working group.

He said: "The loss of biodiversity threatens the survival of some of the world's poorest people and closes down options for sustainable development in the future."

Professor Crane told BBC News Online: "In many parts of the world biodiversity is in terrible shape.

"There's no question the alarm bell is ringing. What we need are clear, credible measurements to bring its message home."