''Evolving the Alien: The Science of Extraterrestrial Life'' (published in the US, and UK second edition as ''What Does a Martian Look Like?: The Science of Extraterrestrial Life'') is a 2002 popular science book about

xenobiology Xenobiology (XB) is a subfield of synthetic biology, the study of synthesizing and manipulating biological devices and systems. The name "xenobiology" derives from the Greek word ''xenos'', which means "stranger, alien". Xenobiology is a form o ...

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

Jack Cohen and

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

Ian Stewart.Jack Cohen and Ian Stewart: ''Evolving the Alien: The Science of Extraterrestrial Life'', Ebury Press, 2002, Jack Cohen and Ian Stewart: ''What Does a Martian Look Like: The Science of Extraterrestrial Life'', Wiley, 2002Jack Cohen and Ian Stewart: ''What Does a Martian Look Like: The Science of Extraterrestrial Life'', Ebury Press, 2004, The concept for the book originated with a lecture that Cohen had revised over many years, which he called POLOOP, for "Possibility of Life on Other Planets".

Synopsis

Cohen and Stewart argue against a conception of extraterrestrial life that assumes life can only evolve in environments similar to Earth (the so-called

Rare Earth hypothesis In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity such as sexually reproducing, multicellular organisms on Earth (and, subsequently, human intelligenc ...

), and that extraterrestrial lifeforms will converge toward characteristics similar to those of life on Earth, a common trope of certain

science fiction Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel uni ...

styles. They suggest that any investigation of extraterrestrial life relying on these assumptions is overly restrictive, and it is possible to make a scientific and rational study of the possibility of life forms that are so different from life on Earth that we may not even recognise them as life in the first instance. Cohen and Stewart return to two contrasts throughout the book. The first is between ''exobiology'' (which considers the possibilities for conventional, Earth-like biology on Earth-like planets) and ''xenoscience'' (which embraces a much broader and more speculative range for the forms that life may take). The second contrast drawn is between ''parochials'' (features of life that are likely to be unique to Earth) and ''universals'' (features that are likely to appear wherever life arises). Cohen and Stewart supplement the limited hard science available on their subject with numerous references to

of both their own and others' creation, including 28 plot summaries of classic SF stories.

Reception

In its review of ''Evolving the Alien'', the ''London Review of Books'' commented that Cohen and Stewart's speculative approach is useful in exposing errors in conventional thinking, and is "painlessly educative" on the current state of the applicable sciences, but criticized their "naive optimism" with respect to future technological breakthroughs in human space travel. In his review for ''Nature'', Lawrence M. Krauss admitted to not being completely sure of the book's intended goal and audience, but noted that it may serve as a counterpoint to arguments put forth in Peter Ward and Donald Brownlee's book, '' Rare Earth''.

References

{{reflist Books by Ian Stewart (mathematician) Books about extraterrestrial life 2002 non-fiction books Ebury Publishing books