Energy (Continued) 

 use of by saprovores or trans- 

 formers after loss from trophic 

 levels, 202 

 use of for processes of existence, 

 201 

 Environment {see also Communities; 

 Cycles; Habitats; Microhabitats; 

 Niches): 

 adaptations to: 

 as necessary characteristic of 



early organisms, 6 

 by mammals to use energy 



resources, 8 

 during orientation, 12, 13 

 of distinguishing characteristics 



of species, 265-266 

 sessility and motility in consider- 

 ing, 7 

 through learning, 14, 15 

 and law of the minimum, 12 

 and law of toleration, 10-11, 11-12 

 and stimuli, 13, 14 

 as restraining rate of growth of 



populations, 220 

 balance with of organisms and 



low net reproduction rates, 217 

 changes in: 

 as affecting period of time 



required for evolution, 267 

 physiological adjustments as 



first responses to, 10 

 through biotic succession, 21-23 

 through climatic succession, 21- 



24 

 through geologic succession, 24- 



26 

 through physiographic succession, 

 .24 



types of responses to, 6 

 classification of species in, 20 

 cycles in: 

 and ultra-violet radiations, 243- 



244 

 of sunspots, 243 

 of weather, 243 

 deficiencies in and organisms of, 



10 

 differences between subspecies or 

 populations as correlated with 

 differences in, 257-258 

 diversification of species con- 

 ditioned by, 6 

 divisions of, 6 

 dominance in, 18, 19 

 effect of on organisms: 

 controlling, 10 

 directive, 10 

 lethal, 10 

 masking, 10 

 evaluation of species in, 20, 21 

 experimental testing of factors 

 in, 13 



Environment (Continued) 



"influences" in and community 

 character, 19 



key to offered by kind of commun- 

 ity present, 18 



heterogeneity of as helping indi- 

 viduals escape full force of 

 density-dependent effects, 229 



individualistic concept of com- 

 munities in, 27 



morphological variation an aspect 

 of influences in, 7 



most critical factors of in deserts, 

 338 



of alpine tundra as imposing great 

 severities on plant development, 

 316 



organismic concept of communities 

 in, 26-27 



reactions to on basis of inherited 

 behavior patterns, 13 



relation of mutations to, 9, 262-263 



uniformity of in various ocean 

 bottoms, 370 



vegetation- types in, 28-29 



wide range of intensivity of factors 

 in, 10 

 Erosion: 



action of wind in, 168 



and formation of lakes, 59 



and formation of permanent 

 streams, 42 



and silting, 56 



as factor in population reduction 

 of oysters, 229 



conditions of occurrence of, 56 



control of as basic to fish manage- 

 ment, 58 



control of to permit oyster spat 

 to set, 371 



danger of to animals in streams, 

 52 



effects of animal burrowing on, 165 



influence of on kinds of fish in 

 streams, 56 



in physiographic succession, 24 



methods for prevention of, 56-57 



of desertic soils, 172 



of grasslands from overgrazing, 

 128 



of river soil as means of dispersal 

 of fresh-water organisms, 146 



of rock by water, 168 



products of in topography of 

 desert, 333 



protection from by mangroves, 

 368 



role of in mountain- building of 

 North America, 280, 281 

 Ethology: 



and isolation mechanisms of 

 sympatric species, 258 



defined, 14 



Ethology (Continued) 



differences between, and psychology, 

 14 

 Evaporation (see also Humidity; 

 Moisture); 



and humidity in grasslands and 

 forests, 121 



and saline soils, 172 



decrease in through evolution of 

 moist membranes in body, 99 



factors causing, 97 



high rate of in deserts, 332 



in moist-skinned animals, 101 



low rate of in cloud forests of 

 tropical biomes, 341 



measurement of, 97 



of rainfall termed interception, 121 



prevention of excessive amounts 

 of by coniferous forest leaves, 

 301 



use of by bees to cool hive, 174-175 

 Evolution {see also Adaptation(s) to 

 Terrestrial Habitat(s); Morpho- 

 logical Adaptation(s); Mutations): 



accumulation of favorable varia- 

 tions and adaptation in, 264-265 



adjustment to particular habitat as 

 aspect of diversification of 

 species, 6 



and asexual and self-fertilizing 

 forms, 264 



and creation of struggle for exis- 

 tence, 264 



and hybridization, 263-264 



and origin of life, 96, 354 



and preadaptation, 266 



and succession from sea to fresh 

 water, 368-370 



and succession from sea to land, 

 367-368 



and survival of the fittest, 264 



as lowering frequency with which 

 population replaces itself, 211 



differential survival in, 264 



elaboration of behavior patterns 

 through, 13 

 emergent, 26 



factors affecting rate of, 267 



inheritance of growth- forms as 

 result of, 7 



importance of continents in, 151 



macro-evolution, defined. 260 



manifestations of cooperation in, 

 27-28 



micro-evolution, defined, 260 



natural selection in, 9, 264-265 

 and distinctive characteristics of 



species, 265-266 

 and favorable mutations, 262-263 

 and mutations of disease organ- 

 isms, 228 

 as fostering improvement of 

 species, 264-265 



416 



Index 



