Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Tree of LifeKeepers of the Biosphere
Dangerous Friends and Friendly Enemies
Creators of the Future

(home) Origins | Biosphere (to Puzzle)

The Pieces
Mapping the DNA of the Thermatoga was the job of Dr. Karen Nelson, at The Institute for Genomic Research. Researchers at TIGR have mapped the DNA of many species, and are participating in the largest DNA sequencing project in history, the Human Genome Project.

Dr. Nelson's methods include using advanced chemical techniques and computer-aided analysis to quickly identify the four primary building blocks of DNA, labeled with the letters A, G, C, and T. Every strand of DNA is composed of thousands to millions of these proteins, arranged in a specific order that determines the genetic makeup of each life form.

After sequencing Thermatoga's genome, Nelson and her team began a close analysis, and they were amazed by what they found. Even though Thermatoga has been classified among the bacteria, it also shares many genes with another branch of life, the archae. This was convincing evidence that Thermatoga was very close to the beginning of life on Earth, close to the base of the tree, before the bacteria and archae branches split apart.

The theory that Thermatoga is one of the closest living descendants of the first life on Earth is also supported by the fact that every other species studied so far, including human beings, has some of the exact same DNA found inside Thermatoga. Sections of microbial DNA have survived the evolutionary changes that resulted in human DNA.

(home) Origins | Biosphere (to Puzzle)



Tree of Life | Biosphere | Friendly Enemies | New Age | Game of Life
Home | Site Map

Copyright © 1999 Oregon Public Broadcasting and PBS Online