C. elegans similar to these are at B.C.'s Simon Fraser University so researchers can study the effects of space radiation after dozens of generations reproduced at the International Space Station. ((Simon Fraser University/Canadian Press))

Thousands of worms that hitched a ride to Earth on the shuttle Atlantishave arrived safelyat a B.C. university, where they could shed light on how space radiation affects humans.

The worms landed with the shuttle Friday afternoon at Edwards Air Force Base in California, six months after their ancestors — now long dead — were sent to the International Space Station.

"The worms are at the lab and appear to be fine," molecular biologist Bob Johnsen told CBC News on Monday.

The wormswere sent tothe space stationto multiply rapidly, a special skill of the C. elegans worm, so Johnsen and his research team at Simon Fraser University in Burnaby could examine their descendants' genes for mutations.

"We are looking for damage to DNA caused by space radiation," Johnsen told CBC News.

The goal is to relate the information to potential effects on humans, who — from a scientific perspective — have a lot in common with the pencil-tip-sized wrigglers.

"Both genomes have been sequenced and comparisons show that at least 50 per cent of genes are similar and therefore probably have similar functions. That includes DNA repair systems," said Johnsen.

"The worms have the basics of higher organisms— muscle, gut, nervous system, skin, complex reproductive system.The worm is transparent and the entire cell lineage is known," he said.

"We can take DNA from worms from space and run it against a chip [DNA microarray] to see if there is any damage."

It will take several months before they can draw any conclusions.

Each C. elegans worm lives only a week or two, but itsoffspring number in the hundreds.

While worms and other creatures have made their homes on the International Space Station before, this is the longest duration and the first time many generations have developed in space.

In 2003, C. elegans worms being used for other research were found intact in the wreckage of the Columbia space shuttle.

The Simon Fraser researchers are among several groups studying the worms. Some of the observers included students who watched them during the six-month voyage using special cameras set up on the space station.