546 



INDEX 



Pisces, 3 1 1 



See also Fish 

 Pithecanthropus, 237, 238, 239, 240, 250, 

 251 

 erect us, 238 

 pekinensis, 238 

 Placenta, 53, 59, 60, 69, 797-192 

 Placental mammals, 137, 190, 191-192, 

 195,220,262,266,504 

 dispersal of, 268-272 

 See also Mammals 

 Placoderm, 137, 154, 157-158, 760 

 Plants, backcrossing in, 479 

 breeding season of, 472 

 cross-pollination prevented in, 472, 



473 

 disharmonic, 286, 290, 291 

 green, nutrition of, 84-85, 90; photo- 

 synthesis in, 84, 87-88, 90, 91, 145 

 hybrid, successful, 478-479 

 multiple genes in, 391-393 

 Pennsylvanian, 164 

 Permian, 166 

 speciation in, 418-420 

 terrestrial, first, 137, 154, 155 



See also Hybridization, introgres- 

 sive; Tree 

 Plasticity, see Adaptation 

 Platyhelminthes, 72, 73 

 Platypus, duckbilled, 189, 262 

 Platyspiza, 295 

 Pleiotropic gene, see Genes 

 Pleistocene period, 137, 193, 194-195, 

 206, 213, 216, 225, 228, 232, 237- 

 238, 240, 247, 249, 254, 268, 269, 

 271, 272 

 Plesiosaurs, 777, 185 

 Pliocene period, 120, 137, 194, 205, 206, 



225,226,228,237,271 

 Pliohippus, 204, 205-206, 409, 410 

 Pliopithecus, 224, 227 

 Pocket gopher, 28 

 Pocock, 158 

 Polar body, first, 383, 384, 385 



second, 383, 384, 398, 399 

 Polygamy, 492 



Polygenes, see Genes, multiple 

 Polymorphism, 375-376 



balanced, 369, 465, 468 

 Polynesia, 291 



Polyploidy, 399-400, 418-420, 474, 503 

 Polypterus, 163 

 Pongidae, 228, 232 

 Population, allopatric, 319, 473-474 

 breeding, effective, 447-448 

 buffered against change, 466 

 defined, 427 

 genetic reserves in, 436, 453, 468, 490 



Population (Continued) 



interbreeding in, see Hybridization 



Malthuson, 352-353 



size of, effect of, 349-351, 360, 441- 



444,445,446,489-491 

 sympatric, 474 



See also Dispersal, means of; 

 Equilibrium; Homeostasis; Num- 

 bers; Subpopulations 

 Population genetics, 349-350, 427-449 

 Population structure, balance hypothesis 

 of, 467-468 

 classical hypothesis of, 467-468 

 Porcupine, 119-120 

 Porifera, 94 

 Porphyropsin, 104-106 

 Porpoise, 15,28,220 

 Porsch, 300 



Position effect, 397-398 

 Postadaptation, 12, 16, 335, 358, 479 

 Postnatal care, importance of, 357 

 Posture, of apes, 229 

 erect, 236 



of Homo sapiens, 229 

 of Neanderthal man, 243 

 of Pithecanthropus, 238 

 Preadaptation, 12-13, 15-16, 158, 159- 



161,335,453,477-478,479 

 Pre-Cambrian era, 143-146 



See also Archeozoic era; Protero- 

 zoic era 

 Precipitin, 1 10 

 Precipitin test, 109-121 



application of, 110-113,777 

 measurement of. 113-115, 1 14 

 Predators, and population size, 353, 356 



protection from, 364-366 

 Preference in mate selection, see Isola- 

 tion, reproductive; Sexual selection 

 Premolars, see Teeth 

 "Presapiens," 242 



Primates, evolution of, 221-248, 224, 247 

 limbs of, see Limbs 

 modern, 222 



orderof, 220-221,310, 312 

 nutrition of, 85 



See also Ape; Chimpanzee; Man; 

 Monkey 

 Primitive streak, 54 

 Primrose, evening, 337, 338, 419 

 Probability, see Chance 

 Proboscidea, 310 



evolution of, 206-216, 277 

 See also Elephant 

 Proboscis, of insects, 35, 36, 40 



of proboscidea, 207-208, 210, 277, 212, 

 270 

 Proconsul, 224, 225, 227, 231, 237 



