SSS 2008-05-05

（单词翻译）

This is Scientific American's 60-Second Science, I’m Steve Mirsky. Got a minute?

Biologists often attempt to construct a genealogy¹ that shows the relationships of all life on earth.  One well-accepted effort compares the nucleic acid sequences that code for ribosomal RNA and a few proteins in many different organisms.  The result shows clear groupings.  The bacteria cluster together, the eukaryotes—that’s you and frogs and maple² trees—all go together.  And archae, a distinct kind of single cell, go together.  A few years ago, researcher Song Yang decided³ to look at similarly shaped regions of proteins in various organisms.  Yang’s mentor⁴, Russell Doolittle, discussed the work at an evolutionary⁵ biology conference on May 1st at Rockefeller University in New York City.  Yang compared the DNA⁶ sequences of the similarly shaped protein sections.  The resulting map of relationships almost completely matched the one made from different data sources.  Which is good confirmation⁷ that the genealogy of life on earth is indeed what researchers thought it was.

Thanks for the minute for Scientific American's 60-Second Science. I'm Steve Mirsky.