Climbing Mount Improbable
Page 33
pupils
changing size of, 166
evolution of, 170
variable shape, 169 (fig.), 168
Quiring, Rebecca, 193
Radiolaria, 235–6 (fig.)
raindrops, and photons, 144
Raup, David, 201–3, 206–7, 211
refraction, principle of, 155 (fig.)
refractive index, 155
relaxation, in evolution, 135–6
reproduction
different from heredity, 88
Muller's Ratchet, 85
sexual, rearranging genes, 83–4
retina
as biological photocell, 145 (fig.)
independent evolution of, 170–1
rods and cones, 172
Robinson, Michael, 53
robot(s)
definition, 281
horse, as vehicle for DNA, 290 (fig.)
industrial, 278–9
movement of, 279
self-duplicating, 281
TRIP, 280–1
rod, retinal, 145 (fig.), 172
saltations, genetic defects, 97
scallop, mirror solutions to image-forming, 176–7
Scyllarus, homeotic mutation, 252 (fig.)
sea-dragon, leafy, 9–10
sea-cows, 130, 131 (fig.) {338}
seeds, with wings, 274 (fig.)
segmentation, 240–55
selection
artificial, see artificial selection
natural, see natural selection
pressure, 198–9
vicarious, 324
sex
evolution of, 85
Muller's Ratchet, 85
recombination of DNA, 90
and rearrangement of genes, 84
reproduction on NetSpinner, 63
spiders, 49
shells
computer simulation, 201, 206 (fig.), 212
artificial selection, 215 (fig.)
resemblance to real shells, 216–7 (fig.)
X-ray view, 209 (fig.)
flare, verm and spire, 204, 207 (fig.)
shapes, 213 (fig.)
theoretical, 218 (fig.)
tube, 204–5
X-ray view, 209 (fig.)
Sherrington, Sir Charles, 326
silk, spider, 39, 68
and sex, 49
stickiness, 41
see also spiders, webs
skate, and flounder, 134 (fig.)
solar panels, and insect wings, 114
soup, primeval, 282
species, classification of, 106
spherical aberration, 173
spiders
bolas, 55–7
female, larger than males, 47
hunting, 51
jumping, 173
male: dangers in mating, 48
mating thread, 49 (fig.)
tying down female, 50 (fig.)
mating, 49, 53, 63
mating thread, 49 (fig.)
poisoning prey, 52
predators, 47
problems for, 43–52
solution to ‘own goal’ hazard, 44
webs, 4, 38–72
building, 43–8
computer simulation, 57–69
evolution on NetSpinner, 62 (fig.)
economy, 41
efficiency of, 38
fine tuning, 49–50
laying thread, 45
optimal tension, 54
problems laying thread, 46–7
radiating spokes, 46
simulation of natural selection, 37
stickiness, 42 (fig.)
spine, flexing, mammals and fish, 123
spire (shells), 203–6 (fig.)
spirula, odd shell, 219
spring hare, 124 (fig.)
sprung trap, spider techniques, 54
squids
flying, 121
independently evolved eyes, 145
squirrel, flying, evolution of, 118
stable balance theory
evidence for, 314
two kinds of males, 313–4
statues
animal, 9
designoid, 10
stones, no offspring from, 26
stress
increased mutation rates, 86
and mutation, 83
mutation penalized by natural selection, 86
sun, and remote guidance technology, 138
superposition, 188, 189 (fig.)
survival, animal, contributions to, 36
symmetry, 225–40
computer biomorphs, 225–7 (fig.)
echinoderms, 238 (fig.)
five-way, 239
four-way, 231 (fig.)
‘Isle of Man’, 232 (fig.)
left-right, 230
radial, 232
six-way, 236, 237 (fig.)
tailorbird, nest, 17 (fig.)
telescope, Keplerian, 187
tenrec, 19, 20 (fig.)
termites
compass, 17
mimicry, 8–9, 8 (fig.)
Terzopoulos, Demetri, 69–71
thermals, 128
Thomas, Keith, 256
Thompson, D'Arcy Wentworth, 201
Thomson, William, 76
‘tortoise’ robot (Machina speculatrix), 280
‘Total Replication of Instructions’ Program (TRIP), 276, 286
trachymedusae, six-way symmetry, 237
transparency, principle of refraction, 155
traps, for insects, 14 {339}
trees
acacia, and ants, 266
and evolution of flight in vertebrates, 115
fig, and fig wasps, 262
real and computerized, 31 (fig.)
Trivers, Robert, 24
trunk, elephant, 4, 92, 94
Tu, Xiaoyuan, 69–71
tube (shells) 204–5, 206 (fig.)
generated by Blind Snailmaker, 212
tusks, elephant, fossilization of, 94
ultraviolet light, and bee vision, 259
University of California, 113
variation, and natural selection, 165
Venus's fly trap, 14
verm (shells), 204–6 (fig.), 207 (fig.)
Vermeij, Geerat, 216
vertebrates
flight, 115
see also birds
gliding, 119 (fig.)
and squids, independently evolved eyes, 145
viruses
biological purpose of, 268–72
computer, 269
DNA, hosts, 274
vitreous mass, 159–61
Vollrath, Fritz, 41, 56
volvox, representing early life, 287
von Frisch, Karl 17
von Neumann, John, 281
vultures, use of thermals, 128
Waldorf, Uwe, 193
Walter, W. Grey, 280
wasps
designoid pots, 15–6
and figs, co-evolution, 262, 301, 307–9, 320, 324–5
freeloader species, 312
parasitic, 311 (fig.)
potter, 16
prey to spiders, 54
selfishness, 320
winged male, 315–6
wingless male, 315–6
water
living in, 130
return to, by large mammals, 130
Watson, J. D., 271
weaverbird, nest, 17 (fig.)
webs, spider, see spiders, webs whales, 130, 131 (fig.)
dry-land history, 130
whippet, artificial selection, 29 (fig.)
Wickramasinghe, Chandra, 75
Williams, George, 293
wings, 4
aerodynamic efficiency, 113
birds and aeroplanes, 127
fig wasps, 301
insects, 241
on seeds, 274 (fig.)
spread of genetic instructions, 273
wolf, artificial selection, 29 (fig.)
worms, primitive compound eyes, 184 (fig.)
Wri
ght, Sewall, 135
Zschokke, Sam, 58 {340}
* * *
* I shall be using Latin names, and I hope I shall be forgiven a schoolmasterly footnote on the conventions governing them because surprising numbers of educated people (perhaps the same people as wince-makingly refer to Darwin's masterwork as Origin of the Species) get them wrong. Latin names have two parts: a generic name (e.g. Homo is a genus) followed by a specific name (e.g. sapiens is the only surviving species of Homo), both written in italics or underlined. Names of larger units are not italicized. The genus Homo belongs to the family Hominidae. Generic names are unique: there is only one genus Homo, only one genus Vespa. Species often share a name with species in other genera, but there is no confusion because of the uniqueness of the generic name: Vespa vulgaris is a wasp, in no danger of being mistaken for Octopus vulgaris. The generic name always begins with a capital letter and the specific name never does (nowadays, although the original convention was that it could if derived from a proper name. Even Darwinii would nowadays be written darwinii). If ever you see (and you often will) Homo Sapiens or homo sapiens it is always a mistake. Note, by the way, that the word ‘species’ is both singular and plural. The plural of genus is genera.
• Judith Flanders has called my attention to the following amusingly relevant story in Robert X. Cringely's book, Accidental Empires. The story concerns the Apple III, a desktop computer of the generation between the famous Apple II and the even more famous Macintosh, launched in 1980: ‘...the automated machinery that inserted dozens of computer chips on the main circuit board didn't push them into their sockets firmly enough. Apple's answer was to tell 90,000 customers to pick up their Apple III carefully, hold it twelve to eighteen inches above a level surface, and then drop it, hoping that the resulting crash would reseat all the chips.’
* After writing this I was informed by a correspondent, Howard Kleyn, formerly of the Cable and Wireless Company, that humans do, as a matter of fact, make something equivalent to a graded index lens. It is actually a graded index optical fibre. By his description, it works like this. You start with a hollow tube of good glass, about a metre long and a few centimetres in diameter, which you heat up. You then puff into the tube finely powdered glass. The powdered glass melts and fuses with the lining of the tube, thereby thickening the lining while narrowing the bore of the tube. Now comes the cunning part. As this procedure progresses, the powder that is puffed in is of gradually changing quality: specifically, it has been ground from glass of progressively increasing refractive index. By the time the hoEow bore has narrowed to nothing, the tube has become a rod made of highly refracting glass at its central core with graduafly decreasing refractive index as you move towards its outer layers. The rod is then heated again, and drawn out into a fine filament. This filament retains the same graded refractive index, from core to periphery, in miniature, as the rod from which it was drawn. It is technically a graded index lens, albeit a very thin, long one. Its lens property is used not for focusing an image but for improving its quality as a light guide which does not allow its beam of light to disperse. Several of these filaments would normally be used to manufacture a multi-stranded optical fibre cable.
* These engaging little animals, whose habit of cocking their heads to look at you gives them an almost human charm, stalk their prey like a cat and then jump on to it explosively and without warning. Explosive it more or less literally is, by the way, for they jump by hydraulically pumping fluid into all eight legs simultaneously — a little like the way we (those of us who have them) erect our penises, but their ‘leg erections’ are sudden rather than gradual.