April 23, 2009

Study finds worm is actually two species

Swedish scientists say animals that seem identical may belong to utterly different species, meaning there may be more species on Earth than thought.

University of Gothenburg researchers led by Professor Christer Erseus and doctoral student Daniel Gustavsson used DNA analysis to discover one of the Earth's most common segmented worms is actually two types of worm.

We could be talking about a large number of species that have existed undiscovered because they resemble other known species, said Erseus. Both species differ in one of the examined genes by 17 percent -- twice as much as the equivalent difference between humans and chimpanzees.

And, said Erseus, as the advanced DNA technology is tested increasingly within various animal groups, it might mean our perception of the Earth's biodiversity needs to be revised.

There could be 10 times as many species in total, compared with what we previously thought, he said.

The new species of worm has not yet been given a name, since researchers have not yet decided which of the two will keep the old name, Lumbriculus variegatus.

The research appears in the journal Molecular Phylogenetics and Evolution.