Book contents
- The Drake EquationEstimating the Prevalence of Extraterrestrial Life through the Ages
- Cambridge Astrobiology
- The Drake Equation
- Copyright page
- Dedication
- Contents
- Contributors
- Foreword
- Preface
- Book part
- Introduction
- 1 Rate of formation of stars suitable for the development of intelligent life, R*, pre-1961
- 2 Rate of formation of stars suitable for the development of intelligent life, R*, 1961 to the present
- 3 Fraction of stars with planetary systems, fp, pre-1961
- 4 Fraction of stars with planetary systems, fp, 1961 to the present
- 5 Number of planets, per solar system, with an environment suitable for life, ne, pre-1961
- 6 Number of planets, per solar system, with an environment suitable for life, ne, 1961 to the present
- 7 Fraction of suitable planets on which life actually appears, fl, pre-1961
- 8 Fraction of suitable planets on which life actually appears, fl, 1961 to the present
- 9 Fraction of life-bearing planets on which intelligent life emerges, fi, pre-1961
- 10 Fraction of life-bearing planets on which intelligent life emerges, fi, 1961 to the present
- 11 Fraction of civilizations that develop a technology that releases detectable signs of their existence into space, fc, pre-1961
- 12 Fraction of civilizations that develop a technology that releases detectable signs of their existence into space, fc, 1961 to the present
- 13 Length of time such civilizations release detectable signals into space, L, pre-1961
- 14 Length of time such civilizations release detectable signals into space, L, 1961 to the present
- Afterword
- Index
- References
10 - Fraction of life-bearing planets on which intelligent life emerges, fi, 1961 to the present
Published online by Cambridge University Press: 05 July 2015
- The Drake EquationEstimating the Prevalence of Extraterrestrial Life through the Ages
- Cambridge Astrobiology
- The Drake Equation
- Copyright page
- Dedication
- Contents
- Contributors
- Foreword
- Preface
- Book part
- Introduction
- 1 Rate of formation of stars suitable for the development of intelligent life, R*, pre-1961
- 2 Rate of formation of stars suitable for the development of intelligent life, R*, 1961 to the present
- 3 Fraction of stars with planetary systems, fp, pre-1961
- 4 Fraction of stars with planetary systems, fp, 1961 to the present
- 5 Number of planets, per solar system, with an environment suitable for life, ne, pre-1961
- 6 Number of planets, per solar system, with an environment suitable for life, ne, 1961 to the present
- 7 Fraction of suitable planets on which life actually appears, fl, pre-1961
- 8 Fraction of suitable planets on which life actually appears, fl, 1961 to the present
- 9 Fraction of life-bearing planets on which intelligent life emerges, fi, pre-1961
- 10 Fraction of life-bearing planets on which intelligent life emerges, fi, 1961 to the present
- 11 Fraction of civilizations that develop a technology that releases detectable signs of their existence into space, fc, pre-1961
- 12 Fraction of civilizations that develop a technology that releases detectable signs of their existence into space, fc, 1961 to the present
- 13 Length of time such civilizations release detectable signals into space, L, pre-1961
- 14 Length of time such civilizations release detectable signals into space, L, 1961 to the present
- Afterword
- Index
- References
Summary
The question of how intelligence evolves on different planets is a central factor in the Drake Equation and informs the fields of bioastronomy, astrobiology, and SETI (the search for extraterrestrial intelligence). In this chapter, I trace the history of our conceptions of intelligence through changes and growth in our understanding of brain evolution, genetics, and animal behavior, and present a modern view of intelligence that places human intelligence in an evolutionary context and linked to the multiple intelligences inhabiting this planet. Much of our current understanding of intelligence as an astrobiological question and, specifically, the nature and much-vaunted uniqueness of human intelligence, should be updated by modern knowledge and divested of outdated ideas such as the scala naturae, progressive evolution and teleology, and the anthropic principle. These notions continue to fuel a fundamental misconception of intelligence as a uniquely human phenomenon with little or no evolutionary or comparative context and, therefore, no way to understand its true biological nature. In this chapter, I will discuss these issues in detail and replace these outmoded notions with new information and insights about how and why intelligence evolves and the levels and distribution of intelligence across species on this planet. Modern understanding of intelligence shows that it is continuous across all animal life on Earth and that the human brain is embedded in the evolutionary web of primate brain evolution and contains the hallmarks of nervous-system evolution traced back to the first life forms on this planet. These updated ideas provide a biological context for understanding the mechanisms and range of intelligence on this planet and should therefore serve the critical purpose of revising notions of fi, leading to more productive outcomes for the study of the evolution of intelligence on this and other planets.
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- The Drake EquationEstimating the Prevalence of Extraterrestrial Life through the Ages, pp. 181 - 204Publisher: Cambridge University PressPrint publication year: 2015