Life Sciences Commons^™

Nonfish Prey Of Wintering Bald Eagles In Lilinois, Given Harper, D. Scott Hopkins, Thomas C. Dunston

Given Harper

A Model For Evaluating Time Constraints On Short-Term Reproductive Success In Altricial Birds1, Larry Clark

Larry Clark

We develop a simple single dimension model incorporating the time and energy commitments of breeding altricial birds in an effort to understand the evolutionary constraints on parental care. We chose time as the dimension of preference, because it is a naturally bounded constraint, e.g., length of day or breeding season. The utility of the model was evaluated by comparing simulations of time allocation of various breeding scenarios for the European starling (Sturnus vulgaris) to field data. The structure of the model may prove useful in determining the evolutionary constraints on parental care imposed by the developmental pattern of chicks.

Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David B. Taylor, Robert L. Mangan

David B Taylor

Gamma irradiation of screwworm, Cochliomyia hominivorax (Coquerel), embryos was used to truncate the life cycle at the prepupal stage. Egg hatch and larval survival were not reduced by dosages ≤8 kilorads (kr). Pupariation and adult emergence were inhibited by dosages ≥2.8 and 1.2 kr, respectively. Larvae, irradiated as embryos with dosages ≤8 kr, successfully infested wounded sheep, although larval weight was lower than normal. A dosage of 5.8 kr was sufficient to prevent pupariation, while permitting larval development to the third instar. Truncation of screwworm development permits the use of artificially wounded and infested animals for screwworm population surveillance and …

Entropy, Information, And Evolution: New Perspectives On Physical And Biological Evolution, David Depew, Bruce Weber

David J Depew

Can recent developments in thermodynamics and information theory offer a way out of the current crisis in evolutionary theory? One of the most exciting and controversial areas of scientific research in recent years has been the application of the principles of nonequilibrium thermodynamics to the problems of the physical evolution of the universe, the origins of life, the structure and succession of ecological systems, and biological evolution. These sixteen original essays by evolutionists, ecologists, molecular biologists, physical chemists, physicists, and philosophers of science provide the best current summary of this developing research program.Chapters in the book's first part - by …

Reproductive Success And Inflorescence Size Of Calopogon Tuberosus (Orchidaceae), David Firmage, F Cole

F. Russell Cole

Reproductive success of Calopogon tuberosus, which produces no nectar, was investigated in relation to inflorescence size and dispersion pattern. Mean inflorescence size was 2.56 (range 1-10). A bagging experiment showed that insects are required for pollen transfer and that fruits are produced from self-, geitonogamous, and cross-pollinations; fruit set was not 100%. Fruit set of nonmanipulated plants was limited by the number of pollinator visits. Reproductive success increased with increasing inflorescence size, although not above theoretical predictions. However, the probability of producing no fruit or contributing no pollinia decreased with increasing inflorescence size since sequential flowering increased the probability of …