Scientists in the US have succeeded in developing the first synthetic living cell.
The researchers constructed a bacterium's "genetic software" and transplanted it into a host cell.
The resulting microbe then looked and behaved like the species "dictated" by the synthetic DNA.
The advance, published in Science, has been hailed as a scientific landmark, but critics say there are dangers posed by synthetic organisms.
| By Maggie Shiels Technology reporter, BBC News, Silicon Valley |
 YouTube wants users to discover and shape the world through video |
Video sharing website YouTube now gets more than two billion hits daily.
That's nearly double the number of people who tune into the US's three prime time TV stations combined, its owners Google have said.
The news comes as the site celebrates the day five years ago when the first beta version of YouTube was launched.
"I see this great growth opportunity in the online video market and we are positioning ourselves to be a leader," co-founder Chad Hurley told BBC News.
"We are a stage and we give everyone in the world an opportunity to participate and that is being a video platform for creating a solution for people to not only upload and distribute their videos on a global basis but to find and share videos."
He also said that while the two billion downloads marked a real milestone "I feel we have much further to go.
