The Cosmic Zoo: Complex Life on Many Worlds

Description

Are humans a galactic oddity, or will complex life with human abilities develop on planets with environments that remain habitable for long enough? In a clear, jargon-free style, two leading researchers in the burgeoning field of astrobiology critically examine the major evolutionary steps that led us from the distant origins of life to the technologically advanced species we are today. Are the key events that took life from simple cells to astronauts unique occurrences that would be unlikely to occur on other planets? By focusing on what life does - it's functional abilities - rather than specific biochemistry or anatomy, the authors provide plausible answers to this question. Systematically exploring the various pathways that led to the complex biosphere we experience on planet Earth, they show that most of the steps along that path are likely to occur on any world hosting life, with only two exceptions: One is the origin of life itself – if this is a highly improbable event, then we live in a rather “empty universe”. However, if this isn’t the case, we inevitably live in a universe containing a myriad of planets hosting complex as well as microbial life - a “cosmic zoo”. The other unknown is the rise of technologically advanced beings, as exemplified on Earth by humans. Only one technological species has emerged in the roughly 4 billion years life has existed on Earth, and we don’t know of any other technological species elsewhere. If technological intelligence is a rare, almost unique feature of Earth's history, then there can be no visitors to the cosmic zoo other than ourselves. Schulze-Makuch and Bains take the reader through the history of life on Earth, laying out a consistent and straightforward framework for understanding why we should think that advanced, complex life exists on planets other than Earth. They provide a unique perspective on the question that puzzled the human species for centuries: are we alone? Front Matter ....Pages i-xii Front Matter ....Pages 1-1 The Cosmic Zoo Hypothesis and the Evolutionary Tool Set (Dirk Schulze-Makuch, William Bains)....Pages 3-12 Pre-conditions for Complex Life (Dirk Schulze-Makuch, William Bains)....Pages 13-32 Front Matter ....Pages 33-33 The First Cell and the Origin of Life Challenge (Dirk Schulze-Makuch, William Bains)....Pages 35-52 Using Light: The Invention of Photosynthesis (Dirk Schulze-Makuch, William Bains)....Pages 53-68 Oxygen: From Poison to Photosystem II (Dirk Schulze-Makuch, William Bains)....Pages 69-76 Endosymbiosis and the First Eukaryotes (Dirk Schulze-Makuch, William Bains)....Pages 77-94 Sex: A New Way of Reproduction (Dirk Schulze-Makuch, William Bains)....Pages 95-105 The First Multicellular Organisms (Dirk Schulze-Makuch, William Bains)....Pages 107-120 The Rise of Complex Animals (and Plants) (Dirk Schulze-Makuch, William Bains)....Pages 121-136 Intelligence, a New Concept? (Dirk Schulze-Makuch, William Bains)....Pages 137-162 Technologically Advanced Intelligence (Dirk Schulze-Makuch, William Bains)....Pages 163-177 Front Matter ....Pages 179-179 How to Test the Cosmic Zoo Hypothesis (Dirk Schulze-Makuch, William Bains)....Pages 181-200 The Great Filter and the Fermi Paradox (Dirk Schulze-Makuch, William Bains)....Pages 201-206 Back Matter ....Pages 207-232