Directionality theory and the evolution of body size

被引:33
作者
Demetrius, L [1 ]
机构
[1] Harvard Univ, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 USA
关键词
Cope's rule; the island rule; Bergmann size clines; evolutionary entropy;
D O I
10.1098/rspb.2000.1295
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Directionality theory, a dynamic theory of evolution that integrates population genetics with demography, is based on the concept of evolutionary entropy, a measure of the variability in the age of reproducing individuals in a population. The main tenets of the theory are three principles relating the response to the ecological constraints a population experiences, with trends in entropy as the population evolves under mutation and natural selection. (i) Stationary size or fluctuations around a stationary size (bounded growth): a unidirectional increase in entropy; (ii) prolonged episodes of exponential growth (unbounded growth), large population size: a unidirectional decrease in entropy; and (iii) prolonged episodes of exponential growth (unbounded growth), small population size: random, non-directional change in entropy. We invoke these principles, together with an allometric relationship between entropy, and the morphometric variable body size, to provide evolutionary explanations of three empirical patterns pertaining to trends in body size, namely (i) Cope's rule, the tendency towards size increase within phyletic lineages; (ii) the island rule, which pertains to changes in body size that occur as species migrate from mainland populations to colonize island habitats; and (iii) Bergmann's rule, the tendency towards size increase with increasing latitude. The observation that these ecotypic patterns can be explained in terms of the directionality principles for entropy underscores the significance of evolutionary entropy as a unifying concept in forging a link between micro-evolution, the dynamics of gene frequency change, and macro-evolution, dynamic changes in morphometric variables.
引用
收藏
页码:2385 / 2391
页数:7
相关论文
共 37 条
[1]  
[Anonymous], PRIMARY FACTORS ORGA
[2]  
Bergmann C., 1847, GOTTINGER STUDIEN, V3, P595
[3]  
BONNER J T, 1968, Journal of Paleontology, V42, P1
[4]  
Bonner J.T, 1988, The Evolution of Complexity by Means of Natural Selection
[5]  
BROWN JH, 1986, EVOLUTION, V46, P939
[6]  
CALDER WA, 1984, SIZE FUNCTION LIFE H
[7]   PROBABILITY OF SURVIVAL OF A MUTANT GENE IN AN AGE-STRUCTURED POPULATION AND IMPLICATIONS FOR EVOLUTION OF LIFE-HISTORIES [J].
CHARLESWORTH, B ;
WILLIAMSON, JA .
GENETICS RESEARCH, 1975, 26 (01) :1-10
[8]   COPES RULE, THE ISLAND RULE AND THE SCALING OF MAMMALIAN POPULATION-DENSITY [J].
DAMUTH, J .
NATURE, 1993, 365 (6448) :748-750
[9]   STATISTICAL-MECHANICS AND POPULATION BIOLOGY [J].
DEMETRIUS, L .
JOURNAL OF STATISTICAL PHYSICS, 1983, 30 (03) :709-753
[10]   GROWTH-RATE, POPULATION ENTROPY, AND EVOLUTIONARY DYNAMICS [J].
DEMETRIUS, L .
THEORETICAL POPULATION BIOLOGY, 1992, 41 (02) :208-236