Weird Life: The Search for Life That Is Very, Very Different from Our Own
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21. National Research Council, Limits of Organic Life, 35.
22. It should be noted that most of the salt in the water of the oceans is sodium chloride; the saline chemistry of the Dead Sea is more complex, also including significant proportions of magnesium chloride, calcium chloride, and potassium chloride.
23. In his retirement, Volcani resumed his studies of Dead Sea biota. In the late 1990s, he opened bottles of enrichment cultures that he had collected half a century earlier and found live microorganisms, at least one of which had never been identified. (Ventosa, Arahal, and Volcani, “Microbiota of the Dead Sea”)
24. Interview with the author, March 19, 2010.
25. Marine Biological Laboratory, “Life at the Extremes.” The Phoenicians are said to have called the Rio Tinto the “River of Fire.” NASA, somewhat more prosaically, calls it a “Mars Analog,” and is conducting research (the Mars Analog Research and Technology Experiment) that seeks microorganisms, akin to those that might live beneath the Martian surface, in the rock and ore several hundred meters beneath the river.
26. Fountain, “Date Palm Seed.”
27. Cano and Borucki, “Revival and Identification of Spores.”
28. Vreeland, Rosenzweig, and Powers, “Halotolerant Bacterium.”
29. Kelvin, “On the Origin of Life,” 202.
30. Pedersen, “Deep Intraterrestrial Microbial Life.”
31. Belozerskaya et al., “Extremophilic Fungi from Chernobyl.”
32. Hart, “Hydrothermal Vents.”
33. Rothschild and Mancinelli, “Life in Extreme Environments.”
34. These include—and some technical language is necessary here—the tricarboxylic acid cycle, glycolysis, and synthetic pathways for the construction of amino acids and sugars.
35. We should not be surprised to learn that Darwin put forth much the same hypothesis, writing, “I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed.” (Darwin, Origin of Species, 380)
36. In fact, it is a reasonable modification of a much-used term. All individuals of a given species, for instance, share a “last common ancestor” that is also the first member of that species.
CHAPTER TWO: A SHADOW BIOSPHERE
1. Darwin, Life and Letters, 498.
2. Paul C. W. Davies, Steven A. Benner, Carol E. Cleland, Charles H. Lineweaver, Christopher P. McKay, and Felisa Wolfe-Simon, “Signatures of a Shadow Biosphere,” Astrobiology 9, no. 2 (2009): 241–49.
3. Maher and Stevenson, “Impact Frustration.”
4. Slater, “Biological Problems.”
5. Erwin, “Tropical Forests,” 74.
6. Wilson, Future of Life, 14. The authors of a 2011 study, using patterns within the taxonomic classification system, estimated the total number of species on Earth to be 8.7 million, give or take 1.3 million. (Mora et al., “How Many Species”)
7. Quoted in Wilson, Diversity of Life, 142.
8. Pace, “Molecular View of Microbial Diversity.”
9. National Research Council, Limits of Organic Life, 29.
10. Wilson, Future of Life, 20.
11. “Life in the Universe,” 3.
12. Navarro-González et al., “Mars-Like Soils.”
13. Stevens and McKinley, “Lithoautotrophic Microbial Ecosystems”; Chapelle et al., “Hydrogen-Based Subsurface Community”; and Lin et al., “Planktonic Microbial Communities.”
14. Sogin, “In Search of Diversity.”
15. Kaufman, “Second Genesis on Earth.”
16. “[Our analyses] demonstrated that intracellular AsO43– was incorporated into key biomolecules, specifically DNA.” (Wolfe-Simon et al., “Bacterium That Can Grow,” 3)
17. Zimmer, “This Paper Should Not.”
18. Ibid.
19. Reaves, “Absence of Arsenate.”
20. Pikuta et al., “Bacterial Utilization.”
21. “Size Limits of Very Small Microorganisms.”
22. Folk, “SEM Imaging.”
23. Uwins, Webb, and Taylor, “Novel Nano-organisms.”
24. Kajander and Ciftcioglu, “Nanobacteria.”
25. Schieber and Arnott, “Nannobacteria as a By-Product.”
26. Young and Martel, “Truth about Nanobacteria.”
27. Asaravala, “Are Nanobacteria Making Us Ill?”
28. Ibid.
29. Smith, “Nanobes.”
30. Darwin, Voyage of the Beagle, 13.
CHAPTER THREE: DEFINING LIFE
1. Interestingly, it may be that Earth orbits a bit outside a sweet spot within the habitable zone, and that life in general would prefer a warmer planet. Biodiversity increases in warmer and wetter climes, and it is greatest in equatorial rain forests, the warmest and wettest places on Earth’s surface. There is no obvious reason to think the trend wouldn’t continue into places steamier still, if there were any. (Impey, “New Habitable Zones,” 24)
2. Schenk et al., “Ages and Interiors.”
3. Impey, “New Habitable Zones,” 25.
4. Hussmann, Sohl, and Spohn, “Subsurface Oceans,” 258–73.
5. Impey, Living Cosmos, 205.
6. Huxley, “On the Physical Basis of Life,” 130–65. In the magnificent conclusion of Origin, Darwin allowed for a vital force, writing, “There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one” (Origin of Species, 384). In the second edition, the phrase “having been originally breathed” is followed with “by the Creator.” Darwin seems to have meant the original wording only figuratively, and he lamented his later revision as disingenuous. “I have long regretted that I truckled to public opinion, and used the Pentateuchal term of creation, by which I really meant ‘appeared’ by some wholly unknown process. It is mere rubbish, thinking at present of the origin of life; one might as well think of the origin of matter” (letter to J. D. Hooker on March 29, 1863, as reproduced in Darwin, Life and Letters, 498).
7. Pirie, “Meaninglessness,” 11–22.
8. Keosian, Origin of Life, 16.
9. Horowitz, “Biological Significance,” 3.
10. For a summary of the view that viruses are nonliving, see Moreira and López-García, “Ten Reasons to Exclude Viruses.” For an argument that definitions of viruses as nonliving amount to “dogma,” see Bandea, “Origin and Evolution of Viruses.”
11. Dawkins, Selfish Gene, 191.
12. Interestingly, Dawkins allows that memes can be produced in nonhuman cultures as well. Songbirds’ songs are mimicked imperfectly, with the imperfections copied by other birds.
13. Gardner, “Fantastic Combinations.”
14. Davies, Eerie Silence, 81.
15. In his book Origins of Life, Freeman Dyson did just that.
16. National Research Council, Limits of Organic Life, 7.
17. Ibid., 6.
18. In 1995, biologist Lynn Margulis and science writer Dorion Sagan recycled Schrödinger’s title What Is Life?, reframing the question with recent knowledge.
19. Cleland, “Life without Definitions.”
20. Pittendrigh, Vishniac, and Pearman, Biology and the Exploration of Mars, 5.
21. Gribbin and Gribbin, James Lovelock, 139–40.
22. In 1965, Earth-based spectrometry analyzed Mars’s atmosphere and found it to be mostly carbon dioxide, indicating a state of thermodynamic equilibrium. Although a later finding would overturn this result (in 2004, the Mars Express mission discovered traces of atmospheric methane that may or may not have a geochemical origin), at the time Lovelock regarded the spectrometry results as persuasive evidence that Mars was lifeless and Viking’s biology experiments unnecessary.
23. Dick, Biological Universe, 147.
24. Cooper, Search for Life on Mars, 149.
25. Ibid., 126–27.
26. Ibid., 37–38.
27. Ibid., 73–74.
28. Ibid., 121.
>
29. Ibid., 120–21.
30. Dick, Biological Universe, 153.
31. Cooper, Search for Life on Mars, 108.
32. Dick, Biological Universe, 155.
33. Ibid., 158.
CHAPTER FOUR: STARTING FROM SCRATCH
1. National Research Council, Limits of Organic Life, 34.
2. Fox, “Life—but Not,” 35.
3. Nuland, How We Live, 157.
4. De Duve, Guided Tour, 293.
5. Biophysicist Harold Morowitz writes, “To be an entity, distinguished from the environment, requires a barrier to free diffusion. The necessity of thermodynamically isolating a subsystem is an irreducible condition of life.” (Beginnings of Cellular Life, 8)
6. Pace, “Universal Nature of Chemistry.”
7. Wells, Early Writings, 146.
8. Cooper, Search for Life on Mars, 84.
9. Angier, Canon, 124.
10. Fox, “Life—but Not,” 37.
11. Bains, “Many Chemistries,” 154.
12. See, for instance, Muller, Zilche, and Auner, “Recent Advances.”
13. Bains, “Many Chemistries,” 154–55.
14. Ibid., 154.
CHAPTER FIVE: A BESTIARY OF WEIRD LIFE
1. Clark, “ESA Chooses Jupiter.”
2. Spohn and Schubert, “Oceans in the Icy Galilean Satellites.”
3. Bains, “Many Chemistries,” 149.
4. Mullen, “Swimming in a Salty Sea.”
5. Reyes-Ruiz et al., “Dynamics of Escaping Earth Ejecta.”
6. Gugliotta, “Fountains of Optimism,” 2.
7. National Research Council, Limits of Organic Life, 74.
8. Benner, Ricardo, and Carrigan, “Common Chemical Model.”
9. McKay and Smith, “Possibilities for Methanogenic Life”; Schulze-Makuch and Grinspoon, “Biologically Enhanced Energy.”
10. McKay and Smith, “Possibilities for Methanogenic Life.”
11. Strobel, “Molecular Hydrogen in Titan’s Atmosphere.”
12. Shiga, “Hints of Life,” 1.
13. Coustenis et al., “Joint NASA-ESA.”
14. Shiga, “NASA Floats Titan Boat Concept.”
15. Lunine, “Titan as an Analog.”
16. Carter, “Anthropic Principle.”
17. Bains, “Many Chemistries,” 161.
18. Amato et al., “Microorganisms Isolated.”
19. Imshenetsky, Lysenko, and Kazakov, “Upper Boundary of the Biosphere.”
20. National Research Council, Limits of Organic Life, 73.
21. Schulze-Makuch and Irwin, “Reassessing the Possibility.”
22. Morowitz and Sagan, “Life in the Clouds of Venus?”
23. Sagan and Saltpeter, “Particles, Environments, and Possible Ecologies.”
24. Sagan, Cosmos, 30.
CHAPTER SIX: LIFE FROM COMETS, LIFE ON STARS, AND LIFE IN THE VERY FAR FUTURE
1. Interview with the author, July 21, 2010.
2. Ibid.
3. Allamandola and Hudgins, “Interstellar Polycyclic Aromatic Hydrocarbons,” 44.
4. In summer of 2007, an international team of researchers found that particles of dust in space might form helical structures that could actually reproduce and evolve. (Tsytovich, “Plasma Crystals”)
5. Dyson, “Time without End,” 453.
6. Ibid., 449.
7. Ibid.
8. Quoted in Dick, Biological Universe, 21.
9. Maude, “Life in the Sun”; Feinburg and Shapiro, Life beyond Earth.
CHAPTER SEVEN: INTELLIGENT WEIRD LIFE
1. Cocconi and Morrison, “Searching for Interstellar Communications.”
2. Dick, Biological Universe, 454.
3. “Life in the Universe,” 63–64.
4. Lunine, “Saturn’s Titan,” 16.
5. Dick, Biological Universe, 434.
6. Hart, “Absence of Extraterrestrials”; Viewing, “Directly Interacting.”
7. Dick, Life on Other Worlds, 218.
8. In 1979 the “extraterrestrial question” was the centerpiece of a conference held at the University of Maryland in College Park. Proceedings were collected in Hart and Zimmerman, Extraterrestrials—Where Are They?
9. Morrison, “Twenty-Five Years of the Search,” 18.
10. Shostak, Confessions.
11. Vinge, “Coming Technological Singularity.”
12. Clarke, 2001: A Space Odyssey, 185–86.
13. West, H. G. Wells, 233.
14. SETI League, “Declaration of Principles.”
15. Tegmark, “Multiverse Hierarchy,” 8.
16. Freudenthal, Lincos.
17. Nagel explains as follows: “The fact that we cannot expect ever to accommodate in our language a detailed description of Martian or bat phenomenology should not lead us to dismiss as meaningless the claim that bats and Martians have experiences fully comparable in richness of detail to our own. It would be fine if someone were to develop concepts and a theory that enabled us to think about those things; but such an understanding may be permanently denied to us by the limits of our nature.” (“What Is It Like to Be a Bat?” 440)
18. Hempel and Shepard, Unleashed.
19. Wilson, Anthill.
20. Drake and Sobel, Is Anyone Out There?, 47.
21. Dudzinski and Frohoff, Dolphin Mysteries, 119.
22. Gopnik, “Plant TV.”
23. Ibid.
24. Dick, Biological Universe, 266.
CHAPTER EIGHT: WEIRD LIFE IN SCIENCE FICTION
1. Wayne Douglas Barlowe, Ian Summers, and Beth Meacham, Barlowe’s Guide to Extraterrestrials: Great Aliens from Science Fiction Literature, 2nd ed. (New York: Workman, 1987).
2. Adams, Hitchhiker’s Guide, 40.
3. One of the earliest examples comes from a 1930 work by British author Olaf Stapledon, in which a character explains, “In a few of the younger stars there is life, and even intelligence. How it persists in an incandescent environment we know not, whether it is perhaps the life of the star as a whole, as a single organism, or the life of many flame-like inhabitants of the star.” (Quoted in Dick, Biological Universe, 247)
4. Forward, “When You Live upon a Star.”
5. Dyson, “Time without End.”
6. Hoyle, Black Cloud, 170.
7. Ibid., 149.
8. Dick, Biological Universe, 241.
9. Vernier, “SF of J. H. Rosny.”
10. Darwin, Origin of Species, 248.
CHAPTER NINE: WEIRD LIFE IN THE MULTIVERSE
1. Bruno, L’infinito universo e mondi.
2. Greene, Hidden Reality, 311.
3. Folger, “Physics’ Best Kept Secret,” 7.
4. Rothman, “ ‘What You See Is,” 91. The exactness of the constants provoked intellectual crises for several scientists, including (ironically enough) Fred Hoyle. Hoyle said that his atheism was “shaken” by the discovery that if the carbon resonance level were only 4 percent lower, carbon atoms would not form. In 1981 he told an audience at Caltech, “A commonsense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature.” (Hoyle, “Universe,” 12)
5. Bucher and Spergel, “Inflation in a Low-Density Universe.”
6. Murphy et al., “Possible Evidence.”
7. Davies, Goldilocks Enigma, 139, 149.
8. Jenkins and Perez, “Looking for Life.”
9. Tegmark, “Parallel Universes,” 49.
10. Tegmark, “Multiverse Hierarchy,” 10.
11. Davies, Goldilocks Enigma, 212.
12. Nozick, Philosophical Explanations; Lewis, On the Plurality of Worlds; Barrow, Pi in the Sky.
13. Whitrow, Structure and Evolution, 200.
14. Barrow, Constants of Nature, 251–74.
15. Scheraga, Khalili, and Liwo, “Protein-Folding Dynamics.”
16. Gaudiosi, “ ‘Sims’ Designer.”
EPILOGUE
> 1. Pace, “Universal Nature,” 805.
2. “Extrasolar Planets Global Searches (Ongoing Programmes and Future Projects),” The Extrasolar Planets Encyclopedia, last updated March 13, 2012, http://www.exoplanet.eu/searches.php.
3. “Nonterran life may change the gross characteristics of planetary environments in ways that differ from influences stemming from terran life, and these differences (for example, the relative abundances of atmospheric species) may ultimately be observable over interstellar distances with astronomical facilities now on the drawing board.” (National Research Council, Limits of Organic Life, x)
4. Huygens, Celestial Worlds Discovered, 10.
Works Cited
Adams, Douglas. The Hitchhiker’s Guide to the Galaxy. New York: Harmony Books, 1979.
Adams, Fred, and Greg Laughlin. The Five Ages of the Universe: Inside the Physics of Eternity. New York: Free Press, 1999.
Allamandola, L. J., and D. M. Hudgins. “From Interstellar Polycyclic Aromatic Hydrocarbons and Ice to Astrobiology.” In Solid State Astrochemistry, edited by V. Pirronello, J. Krelowski, and Giulio Manicò, 251–316. NATO Science Series II: Mathematics, Physics and Chemistry. Dordrecht, Netherlands: Kluwer Academic, 2003.
Amato, P., M. Parazols, M. Sancelme, P. Laj, G. Mailhot, and A.-M. Delort. “Microorganisms Isolated from the Water Phase of Tropospheric Clouds at the Puy de Dôme: Major Groups and Growth Abilities at Low Temperatures.” FEMS Microbiology Ecology 59 (2006): 242–54.
Angier, Natalie. The Canon: A Whirligig Tour of the Beautiful Basics of Science. New York: Houghton Mifflin, 2007.
Asaravala, Amit. “Are Nanobacteria Making Us Ill?” Wired, March 14, 2005, http://www.wired.com/science/discoveries.
Bains, William. “Many Chemistries Could Be Used to Build Living Systems.” Astrobiology 4, no. 2 (2004): 137–67.
Bandea, Claudiu I. “The Origin and Evolution of Viruses as Molecular Organisms.” Nature Precedings, October 23, 2009. http://precedings.nature.com/documents/3886/version/1.
Barlowe, Wayne Douglas, Ian Summers, and Beth Meacham. Barlowe’s Guide to Extraterrestrials: Great Aliens from Science Fiction Literature. 2nd ed. New York: Workman, 1987.
Barrow, John D. The Constants of Nature: From Alpha to Omega—The Numbers That Encode the Deepest Secrets of the Universe. New York: Pantheon, 2002.