Becca's New and Hot-- Week 4

My article comes from Scientific American online, at http://www.sciam.com/article.cfm?articleID=2090C7F6-E7F2-99DF-3E988265E9F00613&chanID=sa007. It addresses an interesting topic from the more scientific end of the evolution news spectrum, with the headline "Jumping 'Junk' DNA May Fuel Mammalian Evolution."

Essentially, the article explains a mechanism by which novel functional DNA may arise. Researchers (from Stanford!) did a study where they looked for sequences of DNA in so-called DNA "deserts", or large areas without much functional DNA, that were conserved across different species of mammals. If a section was conserved across humans, chimps, rhesus monkeys, dogs, mice and rats, the researchers considered it highly conserved. As the logic goes, a segment conserved over so many species was conserved for a reason, or else small mutations would have added up. The segments are also located "within striking distance" of genes important during embryological development, so the scientists inferred that they might have some regulatory power. These sections have moved around from species to species, giving them the designation of "transposons," so they would be turned on at different times in different species and cause different outcomes. Basically, as biologist Gill Bejerano puts it, "evolution may have harnessed the bits of junk DNA to control the activities of the nearby genes."

This is a very exciting development, as one of the most mysterious parts of evolution is uncovering molecular mechanisms for it to work; the researchers from the Human Genome Project that made the junk DNA discovery believe they have found a powerful new tool for that to happen. Next step: figuring out what the other 95% of junk DNA does!

Also, my book review is online at http://www.amazon.com/Charles-Darwin-Cyril-Aydon/dp/1841198013/ref=sr_1_2/103-0214173-5036659?ie=UTF8&s=books&qid=1177480453&sr=1-2 with Lauren's, Josh's, and Erika's!