Ecology and Evolutionary Biology Commons^™

Access To Mutualistic Endosymbiotic Microbes: An Underappreciated Benefit Of Group Living, Michael Lombardo

Michael P Lombardo

"The original publication is available at www.springerlink.com"

A central question in behavioral ecology has been why animals live in groups. Previous theories about the evolution of sociality focused on the potential benefits of decreased risk of predation, increased foraging or feeding efficiency, and mutual aid in defending resources and/or rearing offspring. This paper argues that access to mutualistic endosymbiotic microbes is an underappreciated benefit of group living and sets out to reinvigorate Troyer’s hypothesis that the need to obtain cellulolytic microbes from conspecifics influenced the evolution of social behavior in herbivores and to extend it to nonherbivores. This extension is …

On The Evolution Of Sexually Transmitted Diseases In Birds, Michael Lombardo

Michael P Lombardo

"The definitive version is available at www.blackwell-synergy.com".

Sexually transmitted diseases (STDs) in animals are caused by pathogens that are transmitted during copulation. Birds have played an important role in the development of STD-centered theories of mating behavior. However, it is not known whether STDs exist in wild bird populations. While the avian cloaca with its dual functions of gamete transfer and excretion seemingly predisposes birds for the evolution of STDs, the life history patterns of most birds (i.e., seasonal breeders with relatively brief annual periods of sexual activity) suggest otherwise. The importance of STDs as selective forces that shape host …

Alfred Russel Wallace, Geographer, Charles H. Smith

DLPS Faculty Publications

Among the great explorers and thinkers who advanced geography in the nineteenth century and helped it evolve into the subject that exists today is a man who is not always connected with the field, Alfred Russel Wallace (1823–1913). Most commonly recognized as ‘the other man’ in the history of the discovery of the principle of natural selection, Wallace’s commitment to the study of landscape and its physical, biological, and human elements was lifelong, and resulted in a wide range of contributions to biogeography, physical geography, human geography, and ethnography. In this year of the double anniversaries of Charles Darwin’s birth …

Cognitive Representation In Transitive Inference: A Comparison Of Four Corvid Species, Alan B. Bond, Cynthia A. Wei, Alan C. Kamil

Alan Bond Publications

During operant transitive inference experiments, subjects are trained on adjacent stimulus pairs in an implicit linear hierarchy in which responses to higher ranked stimuli are rewarded. Two contrasting forms of cognitive representation are often used to explain resulting choice behavior. Associative representation is based on memory for the reward history of each stimulus. Relational representation depends on memory for the context in which stimuli have been presented. Natural history characteristics that require accurate configural memory, such as social complexity or reliance on cached food, should tend to promote greater use of relational representation. To test this hypothesis, four corvid species …

The Origin Of Human Races And The Antiquity Of Man Deduced From The Theory Of “Natural Selection” (1864), Alfred Russel Wallace

Alfred Russel Wallace Classic Writings

No abstract provided.

Morphological Differences Among Eyeless Amphipods In The Genus Stygobromus Dwelling In Different Subterranean Habitats, David C. Culver, John R. Holsinger, Mary C. Christman, Tanja Pipan

Biological Sciences Faculty Publications

The amphipod genus Stygobromus occurs in a variety of subterranean habitats in North America, including caves, phreatic (groundwater) lakes, and superficial subterranean habitats (seeps and epikarst). The habitats share the absence of light but differ in other features, such as pore size of the habitat, available food, and degree of seasonality. Measurements of body size, antennal size, and antennal segment number of type specimens were compared for 56 species occurring in the eastern United States. Except for differences in body size, differences among species in the four different habitats were not significant. Body size was related to relative pore size …