If selective forces on locomotor ability and reproductive biology differ among habitats, we expect to see relationships between habitat, morphology, and life-history traits. Comparative (phylogenetically based) analysis of data from 12 pythonid and 12 boid snake species reveals multiple evolutionary shifts in habitat use, notably in the evolution of arboreal habits. Compared to terrestrial and ...

Alternative reproductive tactics (ARTs) coexisting within a population are found in many organisms. Their existence has been an enduring puzzle in evolutionary biology. Why should selection produce distinctly different alternatives to reach the same goal? How can such alternative solutions coexist in a population? What determines their evolutionary stability? Here we outline ultimate and proxim...

Weeds and invasive plants perform the colonization niche by seizing locally available opportunity spacetime created by human activity. The urge to understand and predict weed life history behavior provides a strong scientific and practical motivation to develop models. Most current weed models are quantitative and demographic. This chapter is a critical review of the limitations of demographic ...

Sir,?I trust that Surgeon-Lieutenant-Colonel Moran will not think that I desired to ignore his work on the above subject in any ommiinication with you, whether designed for formal publication or otherwise. I take it, however, that every one interested in the subject is well aware of the fact of Dr. Moran's discovery of the prevalence of the disease in the Gorakhpur district, originally publishe...

The life history, within the rat, of lymphocytes responsive to histocompatibility isoantigens in the mixed lymphocyte interaction was examined by the use of in vivo labeling with tritiated thymidine and radioautography. Lymphocytes in the peripheral blood and H-ARC (mitotic figures in the MLI) were compared with respect to the frequency of labeled cells and the median grain count. The following...

Regulatory T cells expressing the FoxP3 transcription factor have a profound and nonredundant role in several aspects of immunological tolerance. We will review here the specification of this lineage, its population dynamics, and the diversity of subphenotypes that correlate with their diverse roles in controlling inflammation in a variety of settings.

Although a number of studies describe current evolutionary patterns concerning lifehistory evolution, how historical changes in the way organisms interact with their environment have shaped life-history evolution still remains unresolved. In this study, I integrate prospective and retrospective comparative approaches to ask what ecological factors have driven current variation in lifespan of bi...

The embryonic and larval development of the pipefish Syngnathus abaster is described, based on ex situ observations. The full development sequence lasted 24–32 days (at 18–19 C), which was shortened to 21 days at higher temperatures (21–22 C). Newborn juveniles, with a uniform dark brown colouration, immediately assumed a benthic spatial distribution. This vertical distribution pattern remained...

A two-state life history model governed by ODEs is formulated to elucidate the population dynamics of jellyfish and to illuminate the triggering mechanism of its blooms. The polyp-medusa model admits trichotomous global dynamic scenarios: extinction, polyps survival only, and both survival. The population dynamics sensitively depend on several biotic and abiotic limiting factors such as substra...

1. For iteroparous organisms life-history theory predicts a trade-off between current and future reproduction, and therefore the evolution of host responses to current parasite infestation that will maximize lifetime reproductive success. The parasite-induced variation in reproductive success is thus not the net result of parasite infestation alone, but the parasite-mediated outcome of optimal ...