21.2.09

The Promiscuity of Genes: Why, If My Kid Was Interested in Science as a Career, I'd Buy Her a Genomics Kit


From: "Why Darwin Was Wrong About the Tree of Life" - NewScientist
http://www.newscientist.com/article/mg20126921.600-why-darwin-was-wrong-about-the-tree-of-life.html?full=true

"IN JULY 1837, Charles Darwin had a flash of inspiration. In his study at his house in London, he turned to a new page in his red leather notebook and wrote, "I think". Then he drew a spindly sketch of a tree."

"For much of the past 150 years, biology has largely concerned itself with filling in the details of the tree."

"But today the project lies in tatters, torn to pieces by an onslaught of negative evidence. Many biologists now argue that the tree concept is obsolete and needs to be discarded."

"So what happened? In a nutshell, DNA. The discovery of the structure of DNA in 1953 opened up new vistas for evolutionary biology. Here, at last, was the very stuff of inheritance into which was surely written the history of life, if only we knew how to decode it."

"The problems began in the early 1990s when it became possible to sequence actual bacterial and archaeal genes rather than just RNA. Everybody expected these DNA sequences to confirm the RNA tree, and sometimes they did but, crucially, sometimes they did not. RNA, for example, might suggest that species A was more closely related to species B than species C, but a tree made from DNA would suggest the reverse."

"As more and more genes were sequenced, it became clear that the patterns of relatedness could only be explained if bacteria and archaea were routinely swapping genetic material with other species - often across huge taxonomic distances - in a process called horizontal gene transfer (HGT)."

""There's promiscuous exchange of genetic information across diverse groups," says Michael Rose, an evolutionary biologist at the University of California, Irvine."

"The most likely agents of this genetic shuffling are viruses, which constantly cut and paste DNA from one genome into another, often across great taxonomic distances."

"This genetic free-for-all continues to this day."

See a pattern emerging?

We underestimated the importance of DNA.

We underestimated the importance of RNA.

We underestimate the importance of HGT.

We underestimate the importance of viruses.

We underestimate the importance of bacteria.

We underestimate the collaborative and competitive relationships (wars, treaties) that emerge as a result of inter-species interplay (RNA tribes, viruses, bacteria).

Note to self: Keep scribbling in your notebook.

Note to self 2: Forget the soccer field (or at least balance it out with a little RNA-type research) - get your kid to science summer camp. 23andme, can you hook us up with a program for school-age kids?

Posted via web from Jen's posterous

1 comment:

Greg Matthews said...

Jen: Great post. It's a wonderful reminder of how much we DON'T know . . . but points to an exciting future of asking different questions than we ever thought we'd need to ask.