title: Galactic punctuated equilibrium: how to undermine Carter's anthropic argument in astrobiology.
abstract: A new strategy by which to defeat Carter's "anthropic" argument against extraterrestrial life and intelligence is presented. Our approach is based on relaxing hidden uniformitarian assumptions and considering instead a dynamical succession of evolutionary regimes governed by both global (Galaxy-wide) and local (planet- or planetary system-limited) regulation mechanisms. Notably, our increased understanding of the nature of supernovae, gamma-ray bursts, and strong coupling between the Solar System and the Galaxy, and the theories of "punctuated equilibria" and "macroevolutionary regimes" 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.
authors: Astronomical Observatory, Belgrade, Serbia. mcirkovic@aob.bg.ac.rs
authors: Milan M
authors: MM
authors: Cirković
authors: Branislav
authors: B
authors: Vukotić
authors: Ivana
authors: I
authors: Dragićević
mesh_terms: D003198:Computer Simulation; D018559:Exobiology; D053476:Extinction, Biological; D005118:Extraterrestrial Environment; D055608:Galaxies; D009010:Monte Carlo Method; D013997:Time Factors