Galactic Punctuated Equilibrium: How to Undermine Carter's Anthropic Argument in Astrobiology
arXiv:0912.4980 · doi:10.1089/ast.2007.0200
Abstract
We investigate a new strategy which can defeat the (in)famous Carter's "anthropic" argument against extraterrestrial life and intelligence. In contrast to those already considered by Wilson, Livio, and others, the present approach is based on relaxing hidden uniformitarian assumptions, considering instead a dynamical succession of evolutionary regimes governed by both global (Galaxy-wide) and local (planet- or planetary system-limited) regulation mechanisms. This is in accordance with recent developments in both astrophysics and evolutionary biology. Notably, our increased understanding of the nature of supernovae and gamma-ray bursts, as well as of strong coupling between the Solar System and the Galaxy on one hand, and the theories of "punctuated equilibria" of Eldredge and Gould and "macroevolutionary regimes" of Jablonski, Valentine, et al. on the other, are in full accordance with the regulation- mechanism picture. The application of this particular strategy highlights the limits of application of Carter's argument, and indicates that in the real universe its applicability conditions are not satisfied. We conclude that drawing far-reaching conclusions about the scarcity of extraterrestrial intelligence and the prospects of our efforts to detect it on the basis of this argument is unwarranted.
3 figures, 26 pages
References in corpus (12)
- The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way
- The Spiral Structure of the Milky Way, Cosmic Rays, and Ice Age Epochs on Earth
- Ice Age Epochs and the Sun's Path Through the Galaxy
- Galactic Gradients, Postbiological Evolution and the Apparent Failure of SETI
- Terrestrial Ozone Depletion Due to a Milky Way Gamma-Ray Burst
- Did a gamma-ray burst initiate the late Ordovician mass extinction?
- Habitable Zones in the Universe
- On The Timescale Forcing in Astrobiology
- Importance of Biologically Active Aurora-like Ultraviolet Emission: Stochastic Irradiation of Earth and Mars by Flares and Explosions
- Does life's rapid appearance imply a Martian origin?
- Intelligent Life in Cosmology
- On the Non-observability of Recent Biogenesis
Cited by in corpus (8)
- The Beginning and the End: The Meaning of Life in a Cosmological Perspective
- On the Origin and Evolution of Life in the Galaxy
- Dependence of Biological Activity on the Surface Water Fraction of Planets
- Long-Term Prospects: Mitigation of Supernova and Gamma-Ray Burst Threat to Intelligent Beings
- Astrobiological Complexity with Probabilistic Cellular Automata
- Type III Societies (Apparently) Do Not Exist
- The Log Log Prior for the Frequency of Extraterrestrial Intelligences
- The Drake Equation at 60: Reconsidered and Abandoned