Robert Ricklefs

..Because of the species-specific nature of these clustered residuals, specialized pathogens are potential candidates to drive spatial anomalies in host abundance...

..To interpret patterns of diversity, we must continue to depend on inductive reasoning inspired by the data of natural history...

..We infer the ancestral area of the present-day bananaquit populations, report on the species' phylogenetic, biogeographic and evolutionary history, and propose scenarios for its diversification and range expansion...

..These analyses show that patterns of distribution across host tree species within an assemblage of Lepidoptera species can be understood, at least in part, in terms of the qualities of the resources upon which they feed...

..Nonetheless, the results of this analysis clearly indicate that a higher rate of diversification in the tropics contributes to the pervasive latitudinal gradient in diversity observed in passerine birds...

..This integrated perspective opens new research directions for ecologists to explore the formation of species, adaptive diversification, and the adjustment of ecological distributions of species on regional scales...

..Ecological reality can be added to the mix while retaining Hubbell's concept of continuity of communities in space and time...

..Although the mechanisms linking embryo growth rate and ageing are not known, a simple model of life-history optimization shows that the benefits of longer life can be balanced by connected costs of extended development...

..Understanding these evolved differences between long-lived and short-lived organisms would seem to be an essential foundation for designing therapeutic interventions with respect to human aging and longevity...

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..Thus, the longest observed lifespans in birds, tyrannosaurs and mammals might be close to the maximum possible...

..Recognizing these biases will encourage the development of more realistic models of diversification and the regulation of species richness...

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..If genetically based or other intrinsic antagonistic pleiotropy underlies the evolution of senescence, it was not evident in our analyses...

..20 to 0.54. The absence of substantial genetic variation for age at death in birds might be related to the stringency of flight, allowing for little variation in the optimization of life-history trade-offs...

..The evidence for both groups suggests that clade size has achieved long-term equilibrium, suggesting negative feedback of species richness on the rate of diversification...

..tropical species cannot be explained completely by the adjustment of reproductive investment in relation to adult survival and the expectation of future life...

..Conservation efforts are strengthened by recognition of aesthetic, cultural and scientific values of the unique flora and fauna of the West Indies...

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..Accordingly, the pervasive increase in clutch size with latitude would appear to reflect increasing availability of food resources to provision offspring...

..We suggest that causes of extrinsic mortality in nature may be replaced in captivity by intrinsically controlled causes of mortality related to processes that regulate the rate of aging...

..93 Myr) and that the 47 modern families comprising 5712 species descended from approximately 430 passerine lineages extant 24 Myr ago. Speciation and extinction rates among small, marginal families might be 1-2 orders of magnitude lower...

..The existence of such phases can be inferred from correlations, albeit weak, between the status of populations in the Lesser Antilles and the ecological and geographic distribution of their putative source populations in the mainland...

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..The results of the DU protocol suggest that T(b) should be measured continuously during measurements of maximum oxygen consumption, and that peak values should be adjusted by T(b) to make them comparable with other studies...

..We offer suggestions on future research directions at the intersection of biogeography and ecology...

..Accordingly, tropical folivore diversity is associated with greater resource niche overlap, greater niche specialization, and/or more completely filled niches, or with variation in niche dimensions not measured in this study...

..Although host switching has been a prominent feature over the evolutionary history of avian malaria parasites, it is infrequent and unpredictable on time scales germane to public health and wildlife management...

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..Comparisons between wild and captive populations appear to support the intrinsic-causes model for birds, but give mixed support for both models in mammals...

..Rather, our results suggest an abrupt, roughly 10-fold increase in colonization rate or a 90% mass extinction event 0.55 to 0.75 million years ago...

..Detailed studies of the phylogeographic distributions of hosts and parasites are needed to characterize these events...

..However, the avifauna of the Lesser Antilles is probably not in equilibrium at present, and the overall species-area relationship might reflect changing proportions of historically distinguishable subsets of species...

..Although competition is a dominant force in ecological communities, variation in the distribution and abundance of individual species might instead reflect the outcome of interactions with specialized antagonists, including pathogens...

..Thus, morphological evolution in birds seems to be associated with cladogenesis. How lineage splitting promotes morphological diversification poses an important challenge to ecologists and evolutionary biologists...

..falciparum at 2.5 million years ago (Ma), the initial radiation of mammalian Plasmodium at 12.8 Ma, and the contemporary global diversity of the Haemosporida across terrestrial vertebrates at 16.2 Ma...

..By similar reasoning, species should accumulate relatively slowly within continental regions. In this essay, I explore the assumptions and some implications of this model for species diversification...

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..However, the parasite-free region is slightly warmer and drier, and it supports less vegetation than the parasite-afflicted region. The influence that this harsher environment may have on vector survival is discussed...

..Our data suggest that the diverse Haemoproteus parasites observed in Galapagos doves are not endemic to the archipelago and likely represent multiple recent introductions...

..Moreover, five divergent lineages of B. torquatus occur within Colombia, highlighting the importance of dense sampling in northwest South America for studies on diversification of widespread Neotropical lineages...

..The high d(N)/d(S) ratio in the cyt b branch separating avian and mammalian parasites and a mammal-parasite codon bias suggest that adaptive evolution has distinguished mammal and bird parasites...

..Yolk corticosterone concentrations increased linearly with laying order. Together, these patterns might reinforce the brood size hierarchy created by asynchronous hatching...

..Future experimental work is needed to ascertain whether the described endocrine changes are responsible for, or result from, prefledging changes in petrel feeding behavior...

..Prevalence (up to 100%) and infection intensity (parasitemias up to 12.7%) of Haemoproteus sp. parasites varied little across island populations...

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..We therefore suggest that species richness and endemism are correlated fortuitously owing to their mutual dependence on the life spans of populations on islands, which is unrelated to speciation itself...

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..We conclude that one measure of each assay type may be required to maximally characterize immune function in studies of a single species, while the same is not true in studies among species...

..8-8.0 titers) vary significantly among species. Accordingly, this assay can be used to compare constitutive innate humoral immunity among species and with respect to age, sex, and experimental treatments within populations...

..Clearly, ecologists should be cautious in relating patterns of variation in haematozoan prevalence to particular host traits...

..Patterns of host-parasite associations within this system suggest both historical co-evolution and ecologically dynamic and independent host-parasite interactions...

..At present, this disease represents an ongoing threat to the birds on the Galapagos Islands...

..These results suggest that developmental effects of maternally derived antibodies, such as imprinting effects on B-cell diversity or autoimmune effects, are important and deserve more consideration in future research...

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..These data suggest that, for both small and large species, deep diving birds rarely if ever exceed tADL(d)...

..Biologists often forget that Charles Darwin offered a way of resolving this issue, and his proposal is ripe for re-evaluation in the light of recent research...

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..Thus, a common set of regional characteristics and processes appears to shape patterns of species richness in a diverse set of taxa, despite substantial differences in their biological traits...

..Therefore, decreasing beta diversity from south to north reflects decreasing climate differentiation within more northerly latitude zones, and primarily post-glacial dispersal limitation north of 50 degrees N...

..Ecologists must evaluate patterns in local diversity within historical and geographic, as well as ecological, contexts...

..Our results indicate that relationships between immune response and infection are not likely to follow a broad general pattern, but instead depend on type of parasite exposure, among other factors...

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..Distinguishing the roles of history, speciation and extinction in the origin of the latitudinal gradient represents a major challenge to future research...

..This suggests that both species interactions and human-aided dispersal influence exotic distributions, although further work on the relative importance of these processes is needed...

..We suggest that these immunological differences could affect fitness in ways that contribute to the contrasting abundances of the two species in North American and Western Europe...

..The close relationship between rates of ITS evolution and species richness further suggests that species production may be directly linked to rate of nucleotide substitution...

..This further indicates that the phenotypic consequences of variation in genome size are dependent on the particular biology of the group in question...

..Chicks of smaller species could maintain a greater temperature gradient at a particular body mass because of their higher mass-specific maximum metabolic rates...

..The best morphological predictor was HL/SVL (speed=-3.28+3.916 HL/SVL, r=0.968, P<0.0001), suggesting that anuran take-off speed is portrayed well with high gear and acceleration distance characterized by hindlimbs...

..We developed a standard operative temperature scale for shorebird chicks. The ratio of evaporative cooling to heat production varied with wind speed and air temperature...

..Neither chick CMI nor adult CMI was related to clutch size, contradicting previous results linking parasite-related mortality to CMI and the evolution of clutch size (reproductive investment) in birds...