Creationists and “intelligent design” writers often claim that scientists cannot explain the origin of life, and further that this deficiency constitutes a major deficiency, indeed a fatal flaw, in modern evolutionary theory.
Countering such claims are numerous discoveries in the origin of life arena, many of them just in the past few years. For a sampling of these discoveries, see Origin. These discoveries also have relevance to Fermi’s paradox and the larger question of whether intelligent life exists elsewhere in the universe — see Fermi.
Many scientists have presumed that any form of biology, whether on the earth or elsewhere, must be based on the six fundamental elements that we see on earth — carbon, oxygen, hydrogen, nitrogen, sulfur and phosphorus — in part because these elements form the basic building blocks of substances such as DNA.
In December 2010, Felisa Wolfe-Simon, a young NASA astrobiology fellow, startled the scientific world with an announcement that she had coaxed a species of bacteria originally found on the shores of Mono Lake in California to utilize arsenic (which is chemically similar to phosphorus) as a substitute for phosphorus, one of the six primary elements of known life that were mentioned above. Cultured in an laboratory environment starved of phosphorus but with plenty of arsenic, generation after generation the bacteria colony substituted more arsenic into its biological processes, until experiments showed that arsenic had even been incorporated into the organism’s DNA [Overbye2010a; WolfeSimon2010].
Wolfe-Simon originally proposed the idea in 2006, but even with the support of famed astronomer Paul Davies she had difficulty getting the scientific community to take her proposal seriously, not to mention to provide funding and employment. Typical of the scientific community’s response was from a prominent British astrobiologist, who quipped, “You’d be off your trolley to go searching for arsenic-based life.” When asked why she named her bacterial species “GFAJ-1,” Wolfe-Simon replied that it stands for “Give Felisa a job” [Davies2010b].
The Wolfe-Simon paper has already generated significant controversy, with some scientists questioning whether the NASA team’s conclusions are justified based on their experimental results, so their discovery might not stand [Zimmer2010]. Also, it is not yet clear whether this discovery has direct relevance to biogenesis. But at the least, this finding, if substantiated, expands the range of possibilities that scientists will need to examine in future research, both in regards to the origin of life on earth and the presence of life in outer space.
For additional discussion, see Origin.
References
- [Davies2010b] Paul Davies, “The ‘Give Me a Job’ Microbe,” Wall Street Journal, 4 Dec 2010, available at Online article.
- [Overbye2010a] Dennis Overbye, “Microbe Finds Arsenic Tasty; Redefines Life,” New York Times, 2 Dec 2010, available at Online article.
- [WolfeSimon2010] Felisa Wolfe-Simon and 11 others, “A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus,” Science, 2 Dec 2010, available at Online article.
- [Zimmer2010] Carl Zimmer, “‘This Paper Should Not Have Been Published’: Scientists see fatal flaws in the NASA study of arsenic-based life, Slate, 7 Dec 2010, available at Online article.
