Scientists Discover ‘Evolutionary oddity’ among ‘bone-eating’ Worms

Scientists at the Scripps Institution of Oceanography have discovered an 'evolutionary oddity' among a species of 'bone-eating' worms living deep underwater.

The Osedax 'bone eaters' were first discovered in 2002 and normally feed on the animal remains, particularly the bones of the remnants. Usually in Osedax populations, the female worms are bigger than the males by a noteworthy margin. But Greg Rouse, a marine biologist with Scripps, found a new Osedax species after checking worm specimens gathered by a remote operated vehicle almost 2,300 feet under the sea.

In the surprising discovery by Rouse, he found that Osedax females were almost the same size of worm species, which were previously discovered and the males were found to be approximately the same size of their female counterparts i.e. around tens of thousands of times larger than the males of the species previously discovered.

The findings have been published in the journal Current Biology. The discovery was made by Rouse and his colleagues Katrine Worsaae of the University of Copenhagen, Nerida Wilson (formerly at Scripps and now at the Western Australian Museum) and Robert Vrijenhoek of the Monterey Bay Aquarium Research Institute.

"This worm was weird enough as it was and now it's even weirder. This shows us that there continue to be mysteries in the sea and there is still so much more to discover, especially since we only found these creatures 12 years ago", said Rouse.

Vrijenhoek said that evolutionary reversals to ancestral states are very uncommon in the animal kingdom and this case is incomparable as the genes for producing full-sized adult males should have degenerated eventually because of disuse, but it appears that the genes are still there.