March 27, 2017


Links to our papers (related to the topic of this site):

(2017) SETI in vivo: testing the we-are-them hypothesis (International Journal of Astrobiology) – journal version and arXiv version.

(2014) Space ethics to test directed panspermia (Life Sciences in Space Research) – journal version and arXiv version.

(2013) The “Wow!-signal” of the terrestrial genetic code (Icarus) – journal version and arXiv version.

Below are some popular-science books and articles that we recommend to a general reader as a material relevant to the topic of this site.

Francis Crick (1981) Life Itself: Its Origin and Nature

In this book, Francis Crick (who won the Nobel Prize for the discovery of DNA structure and also was the key figure in the study of the genetic code) thoroughly examines the hypothesis that terrestrial life might descend from cosmic seeding by an earlier civilization. Crick, together with Leslie Orgel, introduced this hypothesis (which they dubbed “directed panspermia”) in a paper published eight years earlier. In Life Itself, Crick comprehensively considers cosmological and biochemical backgrounds, so this book might have been titled Astrobiology for Dummies just as well, and indeed it is probably one of the best popular books on astrobiology. Though it was written quite some time ago, little has changed since then concerning general questions considered in the book, such as the nature of life as we know it, mechanisms of replication, the uniformity of biochemistry, Fermi’s paradox, etc. Only the chapter on exoplanets is heavily outdated, as recent studies yielded a wealth of new information on that.

Paul Davies (2010) The Eerie Silence: Renewing Our Search for Alien Intelligence

Professor Paul Davies is the chair of the SETI Post-Detection Taskgroup and the author of many non-fiction books related to the fundamental questions in science such as the nature of the universe and the origin of life. In this book one can learn not only about ideas of traditional research in the field of SETI, but also about unconventional approaches, including the biological media as a possible channel for messaging (in fact, this is the book the term “genomic SETI” comes from). Alternatively, you might read his 2004 article at New Scientist which also deals with genomic SETI.

Brian Hayes (1998) The Invention of the Genetic Code (American Scientist, vol. 86, No 1, pp. 8-14 [link])

This article describes the history of deciphering the genetic code, which was much like a detective story spanning a decade starting from 1953. It was known already that the language of DNA employs four letters, while the language of proteins employs twenty letters. The task was to find out how the first language translates to the second one. The whodunit involved even theoretical physicists like George Gamow and Richard Feynman. Some of the ideas, including Crick’s “code without commas”, were ingenious but turned out to be incorrect. The final answer came when Marshall Nirenberg and his collaborators literally cracked the code biochemically without much theorizing (which is not to say that conducting their experiments was a less ingenious job).

Stephen Freeland and Laurence Hurst (2004) Evolution Encoded (Scientific American, vol. 290, pp. 84-91 [link])

A good and short introduction to the genetic code and its basic properties as related to its biological function (specifically, effectiveness in terms of robustness to mutations and errors in translation).

Peter Ward & Donald Brownlee (2000) Rare Earth: Why Complex Life is Uncommon in the Universe

Besides being one of the best popular books on astrobiology, this book presents what is now called the Rare Earth hypothesis, which is, in a sense, an antipode to the Copernican principle, as far as intelligent life is concerned. The point of the authors is that while microbial life might be more or less common in the Universe (as it is tolerable to a wider range of conditions), complex (and thus intelligent) life is very uncommon, as it requires very specific set of astrophysical and geological circumstances. These include not only right distance from the host star to provide necessary temperature, but even the requirement for a planet to have a right moon to stabilize its axis, plate tectonics providing mountain chains with isolated regions to increase biodiversity, and more. As for its relevance to planetary seeding, the conclusion is that seeding individual planets is very inefficient if you ultimately want to get intelligent life, and therefore a better strategy seems to be in seeding giant clouds which produce star clusters with thousands of stars and their planets.

Douglas Hofstadter (1982) The Genetic Code: Arbitrary?

This is chapter 27 from the book Metamagical Themas, which represents the collection of articles written by Hofstadter for Scientific American during 1980s. Here, Hofstadter considers the question of the arbitrariness of the genetic code, in the sense that its mapping could be different just as well. It might sound trivial to a biologist, but to non-biologists the fact that the mapping of the code is not conditioned by physics and chemistry might be a revelation, as it was for Hofstadter himself. [But keep in mind that Hofstadter is not a biologist, so you should be careful when he makes statements about broader biological contexts. Thus, Hofstadter writes: “Over the past few billion years, a scheme gradually evolved in living beings according to which a unit of one chemical “species” is assigned as a code for a unit of another “species” (the first species here stands for nucleotides, and another species for amino acids). This statement is misleading, as any biologist knows that the current version of the genetic code must have been in place already more than 3.5 billion years ago, at the time of the last universal common ancestor.]

Simon Conway Morris (2003) Inevitable Humans in a Lonely Universe

Simon Conway Morris is a paleontologist known for his study of the Burgess Shale fossils and of the Cambrian explosion. This book is of relevance to cosmic seeding for the reason that it deals with the question of what are the odds of intelligent life-forms evolving from microbial life. In Conway Morris’ view the answer is that intelligent beings are almost inevitable (in fact, he argues that they would look much like, if not exactly like, humans). His arguments are based on what is called convergent evolution – the observation that some similar features in different lineages emerge independently. A classic example is active flight which was invented at least four times during evolution – in insects, birds, reptiles (pterosaurs), and mammals (bats). Some readers tend to ascribe this extreme view to the fact that Conway Morris is a Christian, which might imply a theological background in his arguments. However, similar (though less extreme) versions of this view are adopted by other prominent evolutionary biologists, including Richard Dawkins, and certainly you don’t expect a theological background in this case 🙂 (see Dawkin’s book The Ancestor’s Tale, or his comment here).

Michael Mautner (2000) Seeding the Universe with Life: Securing Our Cosmological Future

This book explores the cosmic seeding from the perspective of humans as the senders. Michael Mautner has also founded the volunteer-based Panspermia Society to promote expansion of life in space.

Tobias Dantzig (1954) Number: The Language of Science

In this book, Tobias Dantzig, a mathematician, recounts the evolution of mathematical ideas, and of the number concept above all. We are so accustomed to many mathematical concepts we use today (such as positional notation and the concept of zero) that many of us take them for granted. This book reminds you how all these things became a great product of cultural evolution. A quote from the book: “Conceived in all probability as the symbol for an empty column on a counting board, the Indian sunya was destined to become the turning-point in a development without which the progress of modern science, industry, or commerce is inconceivable. And the influence of this great discovery was by no means confined to arithmetic. By paving the way to a generalized number concept, it played just as fundamental a rôle in practically every branch of mathematics. In the history of culture the discovery of zero will always stand out as one of the greatest single achievements of the human race.”

Following the quote from the previous book by Dantzig, we point out two books that are entirely dedicated to… zero:
Robert Kaplan (1999) The Nothing That Is: A Natural History of Zero
Charles Seife (2000) Zero: The Biography of a Dangerous Idea

Terrence Deacon (1997) The Symbolic Species: The Co-evolution of Language and the Brain

Apart from introducing an intriguing theory about evolution of language, this book by a biological anthropologist Terrence Deacon also covers basic notions of semiotic mechanisms behind culture. This is relevant for making distinction between culture and nature, which is, by the way, the major task of SETI enterprise.

Extraterrestrial Altruism: Evolution and Ethics in the Cosmos (2014) Edited by Douglas Vakoch

This book is a compilation of chapters by different authors, edited by Douglas Vakoch of the SETI Institute. As the book’s description goes, it “examines a basic assumption of the SETI: that extraterrestrials will be transmitting messages to us for our benefit. This question of whether extraterrestrials will be altruistic has become increasingly important in recent years as SETI scientists have begun contemplating transmissions from Earth to make contact.” This issue is no less relevant in cosmic seeding, where one should decide about messaging to potential recipients that might evolve from the seeds.