The Ecology and Evolution of Social Organization in the Kangaroo Family (Macropodidae)

Approximately 45 species of kangaroos and their smaller relativesoccupy virtually every terrestrial habitat in Australia. Themost social macropod is the whiptail wallaby, which lives inpermanent, discrete mobs of up to 50 individuals of mixed ageand sex. Group formation is facilitated by their grazing habits,open forest and pasture habitat, partly diurnal activity, andlow level of intraspecific aggressiveness. Pressure from cursorialpredators, plus the whiptail's non-seasonal breeding and briefestrus, make group living adaptive. Ancestral macropods arebelieved to have been rabbit-sized inhabitants of dense forest,omnivorous, nocturnal, and essentially solitary. The major evolutionarytrends in the family have been toward larger size and grazinghabits; the trends toward diurnality and group living have hadmore modest results. Progressive stages in macropod social evolutionmay be represented by the present-day musk rat-kangaroo, thequokka, and the whiptail wallaby.     

On the Relationship of Social Evolution and Ecology in Ungulates

Much of the social behavior and organization of ungulates canbe related to ecological parameters such as fiber content offorage, plant productivity, plant biomass, plant species diversity,productivity gradients, temporal and spatial fluctuations inproductivity, habitat stability, food dispersion, three-dimensionalstructure of habitat, colonization, and predator density anddiversity. These ecological variables can be linked via individualnatural selection with the species' anti-predator strategies,emphasis on different channels of communication, relative frequencyof damaging and non-damaging overt aggression, gregariousnessand group structure, juvenile dispersal, home-range traditions,monogamy and polygamy, sexual dimorphism, territoriality, hierarchicalrank structure, and plasticity of social structures. The ecologicalvariables have primary manifestations which are behavior orwhich affect behavior, as well as secondary manifestations affectingbehavior. There are logical links between the hypothesis linkingecology and behavior discussed here with some principles frombioenergetics, zoogeography, and paleontology. Although linksdo exist between ecology and behavior, they nevertheless representdistinct realms of natural selection in which social behaviorappears as the more conservative element. The theoretical basisfor this is discussed.     

Settlement Ecology: The Social and Spatial Organization of Kofyar Agriculture

Settlement Ecology: The Social and Spatial Organization of Kofyar Agriculture. Glenn Davis Stone. Tucson: University of Arizona Press, 1996. 256 pp.     

高山和极地植物功能生态学研究进展

由于环境条件恶劣,所以高山地区（特别是树木分布线以上区域）和极地地区通常被认为是陆地上最为极端的生境之一,但是高山和极地区域却也拥有众多极具价值的生物资源。因此自1896年以来,作为生物进化研究中的热点和难点。高山和极地植物对生境的适应机制和策略一直倍受研究者们的关注。本文以植物生态学、植物生理学、气象学等学科资料,分析了高山和北极植物的特有生活型,并认为它是一种主要的适应机制。通过对全球主要高山和极地植物生长地的局部气候特点的分析,作者肯定了植物的特化适应现象与极端环境各因素间存在的密切关系。     

Evolution and Ecology of Parthenogenesis in Earthworms

A model for the origin of parthenogenesis in hermaphroditesis developed. If a dominant mutation causing parthenogeneticdevelopment of eggs without affecting meiotic production ofsperm arises, the parthenogens will increase in frequency tofixation. Concomitantly, there is selection for reallocationof resources from male to female-related functions in both parthenogeneticand sexual individuals. Occasional fertilization of unreducedeggs may produce polyploid clones. Both the loss of male-relatedstructures and polyploidy are common in parthenogenetic earthworms.Parthenogenesis should be favored in patchy and temporally unstablehabitats, in which -selection may be expected, because it facilitatescolonization and rapid population growth, and because selectionby the biotic component of the environment presumably is reduced.Parthenogenetic earthworms commonly occur in decaying logs,leaf litter, and the upper, organic layers of the soil, whereassexual species more often inhabit the deeper, more stable soilhorizons. Long-term persistence of clones depends on their abilityto survive and reproduce under a variety of environmental conditions.It is proposed that successful clones possess "general purpose"genotypes that allow persistence in spite of temporal changesand facilitate active dispersal through heterogeneous environmentsbetween patches of prime habitat. Two common clones of the parthenogeneticearthworm Octolasion tyrtaeum seem to possess general purposegenotypes, as they occur in a wide variety of soil and habitattypes and are geographically widespread.     

The Evolution of Ecology

In spite of an early history of interaction, progress in thefields of ecology and evolutionary biology during most of thiscentury has been made largely in parallel, with little creativeexchange until the past two decades. In contrast, recent historyin the two fields shows an exciting and productive trend towarda unified effort in understanding the ecological and evolutionaryforces and constraints that together produce the phenomenonof adaptation. Common themes that have drawn the two fieldstogether in the past decade include an intensified appreciationof discontinuities in time and space, an increased awarenessof the interaction of history and mechanism, a greater concernfor tradeoffs and constraints, and a renewed exploration ofthe role of hierarchy in producing pattern.     

A Response to Testart's Argument on the Evolution of Social Organization in Australia

Testart's hypothesis is placed in historical perspective. The Kaiabara case study, prominent in Testart's paper but of illustrative significance rather than as proof in his book, is discussed. Testart's mathematical analysis of the degree of coherence between the classifications of societies with patrimoieties as against those with matrimoieties provides an interesting means of reaching inferences about the evolution of social organization, although the required quantification involves some difficulties. Testart's further major contribution to the understanding of moiety organization is his proposed principle of classification based on the violator/non-violator diachotomy. He shows this principle to be more consistent with matrilineal than with patrilineal classifications. It is argued that the Eagle-Crow Myth, from which Testart derives the violator-non-violator diachotomy, refers to the Oedipal conflict, and that this is related to the formation of matrilineal moieties. It is further suggested that the taboo on blood, central to the ‘violator’ concept, is connected with matrilineality.     

Chemical Ecology and Biomolecular Evolution

The belief in the Darwinian theory of evolution appeared to be shaken when one tried to interpret statements of molecular biology in it. As a consequence there arose a theory of non-Darwinian neutral evolution. The supporters of this theory believe that under natural conditions no factors exist which can distinguish and select organisms on their internal (molecular) structure. In the opinion of these neutralists natural selection cannot in principle control the molecular constitution of organisms. Contrary to the viewpoint of the critics of neutralism it is impossible to admit that nucleic acids, proteins and other biomolecules can evolve without the participation of natural selection. This controversy in contemporary theoretical biology can be solved by integrating the conceptions of molecular ecology with Darwinian theory. Molecular ecology acknowledges the interactions of organisms by means of chemical substances synthesized by them. Such chemical ecological factors play a leading part in the selective stages of biomolecular evolution. These diverse chemical ecological interrelations take place intensively when living beings interact with parasitic microbes.     

Phytoplankton Evolution, Taxonomy and Ecology

This special issue is a collection of papers dedicated to GretaA. Fryxell by her students, colleagues and children, in honourof her long and distinguished career in the field of phytoplanktontaxonomy and ecology, especially the diatoms. The 21 papersin the book cover several different aspects ranging from taxonomy,ecology, morphology, physiology, toxin production, trophic modes,paleoecology and phylogeny. As expected from the focus of GAF'scareer, diatoms are the focus of most of these papers, whichprovide a wide picture of the state of the art in several     

Social Organization and Knowledge

This paper explores the relationship between different types of social organization, on the one hand, and different modes of knowing and types of knowledge, on the other. Some characteristic distinctions are suggested and supported with evidence, both from diverse areas of theory, and from the study of two contrasting Melanesian cultures: that of the Lavongai of New Hanover and the Tikana of New Ireland.     

Behavioral Ecology of Coyotes: Social Organization,Rearing Patterns,Space Use,and Resource Defense

Two groups of coyotes in which genealogical relationships were known were studied in the Grand Teton National Park, outside of Jackson, Wyoming, U.S.A., from 1977–1982. One group, a pack consisting of parents and some non-dispersing and non-breeding offspring, defended a territory and the food (mainly elk carrion) contained within it, especially during winter, and also had helpers at den sites (5 of 6 were males). The other group, a mated resident pair, all of whose young dispersed during the first year of life, did not defend a territory and never had helpers at dens. Delayed dispersal and retention of some offspring as helpers was related to the presence of an abundant, clumped, and defendable winter food resource. Dispersing yearlings suffered higher mortality than did non-dispersing individuals. Litter size was the same for the pack and resident pair; litter size was not significantly correlated with number of adults in the group or with the number or percentage of pups that survived to 5–6 months of age. The presence of pack helpers was not significantly correlated with pup survival, although there was a positive correlation (r^s = +0.37) between the number of adults attending a den(s) and pup survival. Helpers rarely fed pups and their presence had no appreciable effect on juvenile weight. Helpers partook in den-sitting (pup-guarding), but they did not reduce the amount of time that parents spent at den sites. Helpers also actively initiated and took part in territorial and food defense. The proportion of times that pack members initiated defense was inversely related to intruder density (r = –0.94).     

Human Ecology and the Evolution of Livestock

ABSTRACT

The number of livestock breeds native to a country is related to the size of the human population. This is presumably because in populous countries there are complex requirements for livestock to serve a wide range of functions. However, diversification of breeds within a country or region is also related to ecological factors and to human geography. This relationship is discussed in the context of Africa (1). Breed diversity may be associated with human genetic diversity; this is illustrated by certain sheep breeds in northwest England (2). Studies of the factors giving rise to and maintaining livestock biodiversity are likely to cast light on the development of human cultures.     

Organization and Evolution of Animal Colonies

Based on the theory of organization and evolution of colonies in an extinct group of hemichordate graptolites (Urbanek, 1960, 1990) the relationship between the events in the late astogeny of bryozoan colonies and their somatic and reproductive cycle is proposed. The bryozoan colonies with simple organization are compared with graptoloid colonies and their structure is interpreted within the framework of the morphogen gradient theory. A morphogen produced by the founder-zooid (oozooid) diffuses along the long axis of the colony and controls the phenotypic expression of the size and structure of zooids. Evolutionary changes in the graptoloid colonies involve introduction of new characters and their spreading is also accompanied by gradient changes of their manifestation. Evolutionary mechanisms in bryozoan colonies are considered in terms of penetrance and expressivity of genes. In contrast to graptolites, many bryozoan colonies display multiple zones of astogenetic changes and repetitions.     

The Roles of Phytoestrogens in Primate Ecology and Evolution

Most primates depend heavily on plant foods; thus their chemical composition is key to understanding primate ecology and evolution. One class of plant compounds of strong current interest are phytoestrogens, which have the potential to alter fertility, fecundity, and survival. These plant compounds mimic the activity of vertebrate estrogens, resulting in altered physiology and behavior. Here, we review what is known about phytoestrogens from an ecological and evolutionary perspective. Much of what is known about the effects of phytoestrogens on the endocrine system comes from research on human foods, especially soybeans (Glycine max). Two opposing perspectives have resulted from this research: 1) phytoestrogens provide health benefits, such as cancer prevention, or 2) phytoestrogens act as endocrine disruptors and threaten reproductive health. Studies of wild primates have only recently begun examining the presence of estrogenic plants in the primate diet and the effects of their consumption. Evidence that a number of primate species eat plants containing phytoestrogens and research documenting behavioral and hormonal effects of estrogenic plant consumption for red colobus monkeys (Procolobus rufomitratus) augment captive and laboratory studies to suggest that these compounds promote differential survival and reproduction. Although much debate is currently taking place over the role of phytoestrogens and other endocrine disruptors in human health issues and in threatening biodiversity, we argue that an ecological and evolutionary approach is needed to reach appropriate conclusions.     

Identity and Ecology in Arctic Siberia: The Number One Reindeer Brigade

Identity and Ecology in Arctic Siberia. The Number One Reindeer Brigade. David G. Anderson. New York: Oxford University Press, 2000.253 pp.     

The Ecology of Language Evolution.

The Ecology of Language Evolution. Salikoko S. Mufwene. Cambridge: Cambridge University Press, 2001. 255 pp.