The longevity of habitable planets and the development of intelligent life

Abstract

Why did the emergence of our species require a timescale similar to the entire habitable period of our planet? Our late appearance has previously been interpreted by Carter (2008) as evidence that observers typically require a very long development time, implying that intelligent life is a rare occurrence. Here we present an alternative explanation, which simply asserts that many planets possess brief periods of habitability. We also propose that the rate-limiting step for the formation of observers is the enlargement of species from an initially microbial state. In this scenario the development of intelligent life is a slow but almost inevitable process, greatly enhancing the prospects of future SETI experiments such as the Breakthrough Listen project.

11 pages, 2 figures, published in the International Journal of Astrobiology, Figure 2 now includes new data point from Zhu et al

References in corpus (3)

• The evolution and distribution of species body size
• Evolutionary Model of Species Body Mass Diversification
• The Size Distribution of Inhabited Planets

Cited by in corpus (4)

• On the Rate of Abiogenesis from a Bayesian Informatics Perspective
• If Loud Aliens Explain Human Earliness, Quiet Aliens Are Also Rare
• Multiverse Predictions for Habitability: Fraction of Planets that Develop Life
• Seafloor Weathering and Stochastic Outgassing Unlikely to Significantly Shorten the Future Lifespan of Earth's Terrestrial Biosphere