by Carl Sagan
19. K. Aoki and K. Nozawa, “Average Coefficient of Relationship Within Troops of the Japanese Monkey and Other Primate Species with Reference to the Possibility of Group Selection,” Primates 25 (1984), pp. 171–184; J. F. Crow and Kenichi Aoki, “Group Selection for a Polygenic Behavioral Trait: Estimating the Degree of Population Subdivision,” Proceedings, National Academy of Sciences 81 (1984), pp. 6073–6077.
20. Aoki and Nozawa, op. cit.
21. Jules H. Masserman, S. Wechkin, and W. Terris, “ ‘Altruistic’ Behavior in Rhesus Monkeys,” American Journal of Psychiatry 121 (1964), pp. 584, 585; Stanley Wechkin, J. H. Masserman, and W. Terris, “Shock to a Conspecific as an Aversive Stimulus,” Psychonomic Science 1 (1964), pp. 47, 48.
22. Especially when there is an authority figure urging us to administer the electric shocks, we humans seem disturbingly willing to cause pain—and for a reward much more paltry than food is for a starving macaque (cf. Stanley Milgram, Obedience to Authority: An Experimental View [New York: Harper & Row, 1974]).
23. Translated by Richmond Lattimore (Chicago: The University of Chicago Press, 1951), Book XXI, lines 463–466, p. 430.
Chapter 7
WHEN FIRE WAS NEW
1. Fragment 118 in Herakleitos and Diogenes, Guy Davenport, translator (Bolinas, CA: Grey Fox Press, 1979).
2. Jonathan Barnes, editor, Early Greek Philosophy (Harmondsworth, UK: Penguin Books, 1987), p. 104.
3. Wen-Hsiung Li and Dan Graur, Fundamentals of Molecular Evolution (Sunderland, MA: Sinauer Associates, 1991), pp. 10–12.
4. B. Widegren, U. Arnason, and G. Akusjarvi, “Characteristics of Conserved 1,579-bp High Repetitive Component in the Killer Whale, Orcinus orea,” Molecular Biology and Evolution 2 (1985), pp. 411–419 (bp is an abbrevation for nucleotide basepairs, the letters in the genetic sequences).
5. It can be very serious on the human level. For example, on Chromosome 19 most people have a sequence of nucleotides that goes CTGCTGCTGCTGCTG, a five-fold repeat. But some have hundreds or even thousands of consecutive CTG sequences, and they suffer in consequence from a grave disease called myotonic dystrophy. Some other genetic diseases may have a similar cause.
6. M. Herdman, “The Evolution of Bacterial Genomes,” In The Evolution of Genome Size, T. Cavalier-Smith, ed. (New York: Wiley, 1985), pp. 37–68.
7. Richard Dawkins, The Blind Watchmaker (New York: Norton, 1986), pp. 46–49.
8. J. W. Schopf, private communication, 1991; Andrew W. Knoll, “The Early Evolution of Eukaryotes: A Geological Perspective,” Science 256 (1992), pp. 622–627.
9. Philip W. Signor, “The Geologic History of Diversity,” Annual Review of Ecology and Systematics 21 (1990), pp. 509–539.
10. Sewall Wright, Evolution and the Genetics of Populations: A Treatise in Four Volumes, Volume 4, Variability Within and Among Natural Populations (Chicago: The University of Chicago Press, 1978), p. 525.
11. Sewall Wright, “Surfaces of Selective Value Revisited,” The American Naturalist 131 (1) (January 1988), p. 122. This article was written when the pioneering population geneticist was ninety-eight.
12. Cf. Ilkka Hanski and Yves Cambefort, editors, Dung Beetle Ecology (Princeton: Princeton University Press, 1991); Natalie Angier, “In Recycling Waste, the Noble Scarab Is Peerless,” New York Times, December 19, 1991.
13. Charles Darwin, Origin of Species, quoted in John L. Harper, “A Darwinian Plant Ecology,” in D. S. Bendall, editor, Evolution from Molecules to Men (Cambridge: Cambridge University Press, 1983), p. 323.
14. Clair Folsome, “Microbes,” in T. P. Snyder, editor, The Biosphere Catalogue (Fort Worth, TX: Synergetic Press, 1985), quoted in Dorion Sagan, Biospheres: Metamorphosis of Planet Earth (New York: McGraw-Hill, 1990), p. 69.
Chapter 8
SEX AND DEATH
1. George Santayana, The Works of George Santayana, Volume II, The Sense of Beauty: Being the Outlines of Æesthetic Theory, edited by William G. Holzberger and Herman J. Saatkamp, Jr. (Cambridge: The MIT Press, 1988), Part II, §13, p. 41.
2. Richard Taylor, editor, quoted in George Seldes, The Great Thoughts (New York: Random House, 1985), p. 373.
3. The first clear explanations of sex both as a means of rapid evolution and as an escape of populations—especially small populations—from the cumulative impact of deleterious mutations were made by the geneticist H. J. Muller (e.g., “Some Genetic Aspects of Sex,” American Naturalist 66 [1932], pp. 118–138; “The Relation of Recombination to Mutational Advance,” Mutation Research 1 [1964], pp. 2–9). There is theoretical and experimental support for his proposals (e.g., Joseph Felsenstein, “The Evolutionary Advantage of Recombination,” Genetics 78 [1974], pp. 737–756; Graham Bell, Sex and Death in Protozoa: The History of an Obsession [Cambridge: Cambridge University Press, 1988]; Lin Chao, Thutrang Than, and Crystal Matthews, “Muller’s Ratchet and the Advantage of Sex in the RNA Virus Φ6,” Evolution 46 [1992], pp. 289–299).
Muller stressed that sexual reproduction was hardly necessary for survival, but that “lack of recomination would greatly handicap a species, in long-term evolutionary advancement, in keeping pace with sexually reproducing competitors.” The idea of sex providing a long-term benefit for the species certainly seems to be an example of group selection, as was explicitly noted, without undue alarm, by one of the founders of modern population genetics, R. A. Fisher (The Genetical Theory of Natural Selection [Oxford: Clarendon Press, 1930]). Fisher was one of the first to suggest that, in other cases, what superficially looks like group selection may in fact be kin selection.
4. D. Crews, “Courtship in Unisexual Lizards: A Model for Brain Evolution,” Scientific American 259 (June 1987), pp. 116–121.
5. Raoul E. Benveniste, “The Contributions of Retroviruses to the Study of Mammalian Evolution,” Chapter 6 in R. I. Maclntyre, editor, Molecular Evolutionary Genetics (New York: Plenum, 1985), pp. 359–417.
6. We have scarcely touched on the complexity and diversity of the sexual machinery, both on the molecular level and the level of individual organisms. Nor have we given a full flavor of the debate on what sex is good for. An excellent short summary is in James L. Gould and Carol Grant Gould, Sexual Selection (New York: W. H. Freeman, 1989). See also the influential book by John Maynard Smith, The Evolution of Sex (Cambridge: Cambridge University Press, 1978); H. O. Halvorson and A. Monroy, editors, The Origin and Evolution of Sex (New York: A. R. Liss, 1985); Lynn Margulis and Dorion Sagan, Origins of Sex (New Haven: Yale University Press, 1986); R. E. Michod and B. R. Levin, The Evolution of Sex (Sunderland, MA: Sinauer, 1988); Alun Anderson, “The Evolution of Sexes,” Science 257 (1992), pp. 324–326; and Bell, op. cit. in Note 3.
7. D. J. Roberts, A. B. Craig, A. R. Berendt, R. Pinches, G. Nash, K. Marsh and C. I. Newbold, “Rapid Switching to Multiple Antigenic and Adhesive Phenotypes in Malaria,” Nature 357 (1992), pp. 689–692.
8. W. D. Hamilton, R. Axelrod, and R. Tanese, “Sexual Reproduction as an Adaptation to Resist Parasites (A Review),” Proceedings of the National Academy of Sciences 87 (1990), pp. 3566–3573.
9. Helen Fisher, “Monogamy, Adultery, and Divorce in Cross-Species Perspective,” in Michael H. Robinson and Lionel Tiger, editors, Man and Beast Revisited (Washington and London: Smithsonian Institution Press, 1991), p. 97.
10. E. A. Armstrong, Bird Display and Bird Behaviour. An Introduction to the Study of Bird Psychology (New York: Dover, 1965), p. 305.
11. W. D. Hamilton and M. Zuk, “Heritable True Fitness and Bright Birds: A Role for Parasites?” Science 218 (1982), pp. 384–387.
12. The same bargain is made in the common, sexually repressive version of the story of the Garden of Eden—in which it is sexual activity between Adam and Eve that excites God’s wrath and makes them mortal.
13. This wonderfully vivid image is Frans de Waal’s, in Peacemaking Among Primates (Cambridge: Harvard University Press, 1989), p. 11.
14. Translated by Edward Kissam and Michael Schmidt (Tempe, AZ: Bilingual Press/
Editorial Bilingüe, 1983), p. 47.
Chapter 9
WHAT THIN PARTITIONS …
1. Alexander Pope, An Essay on Man, Frank Brady, editor (Indianapolis: Bobbs-Merrill, 1965) (originally published in 1733–1734), Epistle I, “Argument of the Nature and State of Man, with Respect to the Universe,” p. 13, lines 221–226.
2. An updating after Jakob von Uexküll, “A Stroll Through the Worlds of Animals and Men: A Picture Book of Invisible Worlds” (1934), reprinted in Claire H. Schiller, translator and editor, Instinctive Behavior: The Development of a Modern Concept (New York: International Universities Press, 1957), pp. 6 ff.
3. Six carbon atoms make up the ring in this molecule. Chemists number them in sequence from 1 to 6. The chlorine atoms are attached in the 2 and 6 positions. If instead they were attached in, say, the 2 and 5 positions, the tick of the opposite sex would not be interested.
4. Ticks are arachnids with eight legs, like spiders, tarantulas, and scorpions. They’re a matter of practical concern because they are the vectors for the spread of Rocky Mountain spotted fever, Lyme disease, and other illnesses—of livestock as well as of humans. We’ve described many of the essential sensory skills of a particular species, but other strategies and capabilities appear on closer examination or in other species. Some species have not one but three different mammalian hosts at different stages of their life cycles. Those ticks that live in caves may wait years for an appropriate host. Ticks chemically interfere with fibrinogen and other machinery that works to staunch the flow of their host’s blood, permitting some species to stuff themselves with a hundred times their unfed body weight in blood. Not only butyric acid is sensed in their quest for mammalian blood, but also lactic acid (CH3HCOHCOOH) and ammonia (NH3). Ticks use pheromones for purposes other than attracting the opposite sex—an assembly pheromone, for example, for a gathering of the tribes in cracks and crevices, or in caves. (See Daniel E. Sonenshine, Biology of Ticks, Volume 1 [New York: Oxford University Press, 1991]). Nevertheless, the basic sensory armamentarium of tick life still seems, as it did in the 1930s, very simple.
5. J. L. Gould and C. G. Gould, “The Insect Mind: Physics or Metaphysics?” in D. R. Griffin, editor, Animal Mind-Human Mind (Report of the Dahlem Workshop on Animal Mind-Human Mind, Berlin, March 22–27, 1981) (Berlin: Springer-Verlag, 1982), p. 283.
6. Thomas H. Huxley, “On the Hypothesis that Animals Are Automata, and its History” (1874), in Collected Essays, Volume I, Method and Results: Essays (London: Macmillan, 1901), p. 218.
7. von Uexküll, op. cit., pp. 43, 46.
8. Karl von Frisch, The Dancing Bees (New York: Harcourt, Brace, 1953).
9. A provocative modern discussion, informed by neurophysiology and computer science, is Daniel C. Dennett’s Consciousness Explained (Boston: Little, Brown, 1991). Optimistic assessments of the near future of artificial intelligence and artificial life include Hans Moravec, Mind Children (Cambridge: Harvard University Press, 1988) and Maureen Caudill, In Our Own Image: Building an Artificial Person (New York: Oxford University Press, 1992). A more pessimistic assessment is Roger Penrose, The Emperors New Mind (New York: Oxford University Press, 1990).
10. Quoted in Konrad Lorenz, “Companionship in Bird Life: Fellow Members of the Species as Releasers of Social Behavior,” in Schiller, op. cit., p. 126.
11. René Descartes, letter to the Marquis of Newcastle, quoted in Mortimer J. Adler and Charles Van Doren, Great Treasury of Western Thought: A Compendium of Important Statements on Man and His Institutions by the Great Thinkers in Western History (New York and London: R. R. Bowker Company, 1977), p. 12.
12. Aristotle, History of Animals, Book VIII, 1, 588a, in The Works of Aristotle, Great Books edition, Volume II, translated into English under the editorship of W. D. Ross (Chicago: Encyclopaedia Britannica, 1952) p. 114.
13. Charles Darwin, The Descent of Man and Selection in Relation to Sex (New York: The Modern Library, n.d.) (originally published in 1871) (Modern Library edition also contains The Origin of Species by Means of Natural Selection or the Preservation of Favored Races in the Struggle for Life), Chapters 1 and 3.
14. René Descartes, Traité de l’Homme, Victor Cousin, editor, pp. 347, 427, as translated by T. H. Huxley, in Huxley, Collected Essays, Volume I, Method and Results: Essays (London: Macmillan, 1901), “On Descartes’ ‘Discourse Touching the Method of Using One’s Reason Rightly and of Seeking Scientific Truth’ ” (1870).
15. Voltaire, “Animals,” Philosophical Dictionary (1764), T. H. Huxley, translator, op. cit., ref. 14.
16. Thomas H. Huxley, “On Descartes’ ‘Discourse Touching the Method of Using One’s Reason Rightly and of Seeking Scientific Truth’ ” (1870), and “On the Hypothesis that Animals Are Automata, and its History” (1874), in Huxley, Collected Essays, Volume I, Method and Results Essays (London Macmillan, 1901), pp. 186–187, 184, 187–189, 237–238, 243–244.
17. J. L. and C. J. Gould, “The Insect Mind: Physics or Metaphysics?” in D. R. Griffin, editor, Animal Mind-Human Mind (Report of the Dahlem Workshop on Animal Mind-Human Mind, Berlin, March 22–27, 1981) (Berlin. Springer-Verlag, 1982), pp. 288, 289, 292.
Chapter 10
THE NEXT-TO-LAST REMEDY
1. Thomas Hobbes, Leviathan, or the Matter, Forme and Power of a Commonwealth Ecclesiasticall and Civil, Michael Oakeshott, editor (Oxford Basil Blackwell, 1960), Part 2, Chapter 30, p. 227.
2. Charles Darwin and Alfred R. Wallace, “On the Tendency of Species to Form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection,” Journal of the Proceedings of the Linnean Society: Zoology, Volume III (London: Longman, Brown, Green, Longmans & Roberts, and Williams and Norgate, 1859), p. 50. Here Darwin also describes sexual selection in which the males compete for the favors of the female, or she selects from among several males on the basis of some quality she finds attractive: “This kind of selection, however, is less rigorous than the other,” Darwin said; “it does not require the death of the less successful, but gives to them fewer descendants.”
3. Curt P. Richter, “Rats, Man, and the Welfare State,” The American Psychologist 14 (1959), pp. 18–28.
4. John B. Calhoun, “Population Density and Social Pathology,” Scientific American 206 (2) (February 1962), pp. 139–146, 148; and references cited there.
5. Frans de Waals, Peacemaking Among Primates (Cambridge, MA: Harvard University Press, 1989)
6. Richard Dawkins argues that lowered birth rates in response to overcrowding are explained equally well (not better) by individual as by group selection (The Selfish Gene [Oxford: Oxford University Press, 1989], p. 119).
7. John F. Eisenberg, “Mammalian Social Organization and the Case of Alouatta,’ in Michael H. Robinson and Lionel Tiger, editors, Man and Beast Revisited (Washington: Smithsonian Institution Press, 1991), p. 135.
8. Peter Marler, “Golobus guereza: Territoriality and Group Composition,” Science 163 (1969), pp. 93–95.
9. John F. Eisenberg and Devra G. Kleiman, “Olfactory Communication in Mammals,” in Annual Review of Ecology and Systematics 3 (1972), pp. 1–32.
10. As first pointed out by Charles Darwin (1872) in The Expression of the Emotions in Man and the Animals (Chicago: University of Chicago Press, 1965, 1967), p. 119.
11. C. G. Beer, “Study of Vertebrate Communication—Its Cognitive Implications,” in D. R. Griffin, editor, Animal Mind-Human Mind (Report of the Dahlem Workshop on Animal Mind-Human Mind, Berlin, March 22–27, 1981) (Berlin: Springer-Verlag, 1982), p. 264.
12. Lorenz’s translation from cranish. Konrad Lorenz, On Aggression (New York: Harcourt Brace, 1966), pp. 174, 175.
13. An example:
“My friend and teacher, Bill Drury, invited me to go bird-watching one day on a small island off the coast of Maine. We left bird books and binoculars behind and strode to the nearest small tree growing alone in the open. He then made a series of high-pitched bird sounds and soon the tree began to fill up with birds, themselves mak
ing a series of calls. As the tree started to fill up, it seemed to attract more and more birds, so that as if by magic all small songbirds in the area were streaking toward the tree under which we were standing. By this time Bill was down on his knees, bent over, and most of the time making a deep kind of moaning sound. The birds actually appeared to wait in line to get the closest look at Bill they could; that is, they hopped from branch to branch until they rested on a branch about eight feet off the ground and not more than two feet from my face. As each bird hopped down, Bill, as if on cue, would introduce them. This is a male, black-capped chickadee. You can tell because of the black along the neck and shoulders. I would guess he’s about two to three years old. Can you see if there is yellow on his back between his shoulders? This is a good index of age.
“For me the moment was utterly magical. In a matter of minutes Bill had reduced the distance between us and these birds by orders of magnitude, both physically and socially. Our relationship was so completely different that I was permitted individual introductions at a distance of a couple of feet. Obviously Bill was pulling some kind of trick and had induced some kind of trance through his bird song.… Bill was at first only imitating the mobbing calls of a couple of the small passerines in the area and interspersing these with occasional owl hoots. The owl is deadly at night but is vulnerable in the daytime, and groups of songbirds will mob it in order (presumably) to run it out of their area, or even harass and kill it on the spot. This drew them into the tree at an ever-increasing rate, since mobbing assemblages gain in individual safety with each new arrival (as well as gaining in power to harass the owl). Once they landed in the tree, however, they could see two four-eyed human beings but could not see the owl. Bill’s bending over and hooting from the ground was meant to suggest the owl was hidden underneath him. This drew them as close as they could get for a good look, which put them two feet from my face. Unlike some magic tricks, knowing how Bill’s was done did not detract from my enjoyment.” (Robert Trivers, “Deceit and Self-Deception: The Relationship Between Communication and Consciousness,” in Michael H. Robinson and Lionel Tiger, editors, Man and Beast Revisited [Washington: Smithsonian Institution Press, 1991], pp. 182, 183.)
