When Scientists discovered a evolutionary single-celled organism

More than 500 million years ago, single-celled organisms on Earth's surface began forming multi-cellular clusters that ultimately became plants and animals. Just how that happened is a question that has eluded evolutionary biologists.
Now scientists have replicated that key step in the laboratory using common Brewer's yeast, a single-celled organism. The yeast "evolved" into multi-cellular clusters that work together cooperatively, reproduce and adapt to their environment--in essence, they became precursors to life on Earth as it is today.
The results are published in this week's issue of the journal Proceedings of the National Academy of Sciences (PNAS).
"The first step toward multi-cellular complexity seems to be less of an evolutionary hurdle than theory would suggest," says Gilchrist, acting deputy division director of the National Science Foundation's (NSF) Division of Environmental Biology. "This will stimulate a lot of important research questions."
Using yeast cells, culture media and a centrifuge, it only took the biologists one experiment conducted over about 60 days.
"I don't think anyone had ever tried it before," says Ratcliff. "There aren't many scientists doing experimental evolution, and they're trying to answer questions about evolution, not recreate it."
The results have earned praise from evolutionary biologists around the world.
"To understand why the world is full of plants and animals, including humans, we need to know how one-celled organisms made the switch to living as a group, as multi-celled organisms," says Sam Scheiner, program director in NSF's Division of Environmental Biology.
"This study is the first to experimentally observe that transition," says Scheiner, "providing a look at an event that took place hundreds of millions of years ago."
Multi-cellular yeast is also a valuable resource for investigating Cancer, aging and other critical areas of biology.