One of the basic assumptions about life on Earth may be due for a revision. Scientists have discovered a type of bacteria that thrives on poisonous arsenic, potentially opening up a new pathway for life on Earth and other planets.
If you thumb through an introductory biology textbook, you'll notice that six elements dominate the chemistry of life. Carbon, hydrogen, oxygen and nitrogen are the most common. After that comes phosphorus, then sulfur. Most biologists will tell you that these six elements are essential; life as we know it cannot exist without them.
The recent discovery by Felisa Wolfe-Simon of an organism that can utilize arsenic in place of phosphorus, however, has demonstrated that life is still capable of surprising us in fundamental ways. The results of her research will appear in Dec. 2 issue of the journal Science.