"Milwaukee Journal Sentinel"
One-cell organism linked to humans
Common gene reported, aiding evolution theory
By JOHN FAUBER
of the Journal Sentinel staff
Last Updated: Dec. 18, 2001

A single-cell organism that swam in the Earth's primordial soup hundreds of
millions of years ago is an evolutionary sibling of humans and all other
animals, according to research published Tuesday by University of
Wisconsin-Madison scientists.

While the finding advances the knowledge of human evolution, the idea that
people and pond scum are related is bound to draw criticism from
creationists and other religious groups that abhor the thought of such
genetic connections between people and other species.

At the same time, the paper for the first time provides scientific evidence
of a theory that first sprung up 130 years ago, that certain single-cell
organisms known as choanoflagellates are linked to animals.

"(The author) provides the most compelling modern molecular evidence to
support this 100-year-old classic idea," said Michael Levine, a professor of
genetics and development at the University of California at Berkeley. "It is
wonderful stuff."

Levine predicted that in the coming months the entire genetic code of the
organism would be sequenced by other scientists and compared with that of
humans and other animals. Once that is done, more common genes are likely to
be found, he said.

The paper, co-authored by Sean Carroll and Nicole King of UW's Howard Hughes
Medical Institute, was published Tuesday in the Proceedings of the National
Academy of Sciences.

Studying a certain type of choanoflagellate known as the Monosiga
brevicollis, they found a gene that is found in all animals.

The gene allows cells within an organism to communicate with each other.

"We were thrilled to find it because it never was found outside animals,"
said Carroll, a professor of genetics at UW.

Carroll and others believe it is one of several genes that allowed
single-cell organisms to develop into more complex life forms more than 600
million years ago. The genes allowed single-cell organisms, known as
protozoa, to develop organs and distinct body parts that are unique to the
animal kingdom.

Under a microscope, choanoflagellates look similar to sperm, with tiny tails
that allow them to move through water.

"Choanoflagellates thrive today and are the closest non-animal organisms to
animals," he said. "They are to animals what chimps are to humans, and by
studying some of their genetic characteristics we can begin to make some
strong inferences (about how animals evolved)."

The UW paper also supports the theory that all life evolved from a common
ancestor, most likely a single-cell organism that sprung up in the ancient
oceans more than 3 billion years ago.

However, it's also a theory that is strongly rejected by those who believe
in the creationism that is taught in the Bible.

"It's garbage," said Charles Roessger, a member of the Creation Science
Society of Milwaukee and the Creation Research Society. "There are hundreds
of scientists throughout the world who don't believe that."

Roessger said just because dogs and people both have two eyes doesn't mean
they are genetically related.

"It only tells me that we have one creator," he said.

Different species have similar traits because the creator wanted to be
efficient and "use the same things," he said.

However, Carroll said that in the DNA of choanoflagellates and animals are
footprints that scientifically link the two life forms.

"I'm not going to change anybody's mind who is dead set against evolution,
but the strength of the evidence only increases," he said.

Carroll said he believed the discovery helped paint the bigger picture of
how nature uses the same tools to sculpt life in different ways and how life
diversified and evolved on Earth.

Oryginal: http://www.jsonline.com/news/state/dec01/6337.asp