Claim CB035:
In Miller's experiment demonstrating the formation of complex organics
from simple compounds, the atmospheric composition used was a reducing
atmosphere, with no free oxygen. The early earth probably had a more
oxidizing atmosphere.
Source:
Watchtower Bible and Tract Society. 1985. Life--How Did It Get Here?
Brooklyn, NY, pp. 40-41.
Response:
- Since his first experiment, Miller and others have experimented with
other atmospheric compositions, too (Chang et al. 1983; Miller 1987;
Schlesinger and Miller 1983; Stribling and Miller 1987). Complex
organic molecules form under a wide range of prebiotic conditions.
- It is possible that life arose well away from
the
atmosphere -- for example, around deep-sea hydrothermal vents. This
could make the atmospheric content largely irrelevant.
- The early atmosphere, even if it was oxidizing, was nowhere
near as oxidizing as it is today. It was likely high in hydrogen,
which facilitates the formation of organic molecules (Tian et
al. 2005).
Links:
Gishlick, Alan D. n.d. Icons of evolution? Miller-Urey experiment.
http://www.ncseweb.org/icons/icon1millerurey.html
Tamzek, Nic. 2002. Icon of obfuscation.
http://www.talkorigins.org/faqs/wells/iconob.html#Miller-Urey
References:
- Chang, S., D. DesMarais, R. Mack, S. L. Miller, and G. E. Strathearn.
1983. Prebiotic organic syntheses and the origin of life. In:
Schopf, J. W., ed., Earth's Earliest Biosphere: Its Origin and
Evolution. Princeton, NJ: Princeton University Press, pp. 53-92.
- Miller, S. L. 1987. Which organic compounds could have occurred on
the prebiotic earth? Cold Spring Harbor Symposia on Quantitative
Biology 52: 17-27.
- Schlesinger, G. and S. L. Miller. 1983. Prebiotic synthesis in
atmospheres containing CH4, CO, and CO2. I. Amino acids. Journal of
Molecular Evolution 19: 376-382.
- Stribling, R. and S. L. Miller. 1987. Energy yields for hydrogen
cyanide and formaldehyde syntheses: the HCN and amino acid
concentrations in the primitive ocean. Origins of Life and Evolution
of the Biosphere 17: 261-273.
- Tian, F., O. B. Toon, A. A. Pavlov and H. De Sterck. 2005. A
hydrogen-rich early Earth atmosphere. Science 308: 1014-1017. See
also: Chyba, C. F. 2005. Rethinking Earth's early atmosphere.
Science 308: 962-963.
created 2001-2-17, modified 2005-6-18
