Does the Rapid Appearance of Life on Earth Suggest that Life Is Common in the Universe?
Abstract
It is sometimes assumed that the rapidity of biogenesis on Earth suggests that life is common in the Universe. Here we critically examine the assumptions inherent in this iflifeevolvedrapidlylifemustbecommon argument. We use the observational constraints on the rapidity of biogenesis on Earth to infer the probability of biogenesis on terrestrial planets with the same unknown probability of biogenesis as the Earth. We find that on such planets, older than ~1 Gyr, the probability of biogenesis is >13% at the 95% confidence level. This quantifies an important term in the Drake Equation but does not necessarily mean that life is common in the Universe.
 Publication:

Astrobiology
 Pub Date:
 August 2002
 DOI:
 10.1089/153110702762027871
 arXiv:
 arXiv:astroph/0205014
 Bibcode:
 2002AsBio...2..293L
 Keywords:

 BIOGENESIS;
 DRAKE EQUATION;
 Astrophysics
 EPrint:
 21 pages, 5 figures, conforms to published version, Figure 5 corrected lowering probability cited in previous version, references updated