'Dracula Ants' May Be Evolutionary Link

ByABC News
January 10, 2001, 9:50 AM

S A N   F R A N C I S C O, Jan. 10 -- A colony of cannibalisticants discovered in Madagascar represent an important piece of thepuzzle in understanding the evolution and behavior of one of themost successful insect species in the world, scientists saidtoday.

The fearsome-looking insects, dubbed Dracula ants by theirdiscoverers because they suck nourishment from their own larvae,are believed to be a transitional species bridging the gapbetween ants and the wasps from which they evolved millions ofyears ago.

A living organism cannot be a true missing link, said BrianFisher of the California Academy of Sciences, who found the antcolony hidden in a rotten log about 55 miles outside ofthe capital Antananarivo.

But this represents our best hope for understanding what thecommon ancestor was, which has been a huge impediment forunderstanding ant evolution.

While ants make up only about one percent of all describedinsect species, they are among the most widely spread andnumerically dominant on Earth and researchers want tounderstand the evolutionary secret to their success.

Ants Have Wasp Waist

Madagascar, an island off southeastern Africa, is regarded asa treasure trove of biological information because its relativeisolation allowed older, or relic, species to survive withoutcompetition from newer arrivals.

While the genus of the Dracula species was first identifiedin Madagascar in 1993, Fishers discovery of the first entirecolony of the insects allows scientists to draw a more detailedpicture of ant evolution.

The Madagascar ants, belonging to the genus Adetomyrma, havejust a single connection between their thorax and their abdomeninstead of the two or three joints found in modern ant species,Fisher said.

They have got this wasp waist, if you will, he said, addingthat the single joint was a clear indication of the ants link toearlier wasps.