Annual Review of Ecology, Evolution, and Systematics
Công bố khoa học tiêu biểu
Sắp xếp:
Corridors for Conservation: Integrating Pattern and Process Corridors are commonly used to connect fragments of wildlife habitat, yet the identification of conservation corridors typically neglects processes of habitat selection and movement for target organisms. Instead, corridor designs often are based on binary patterns of habitat suitability. New technologies and analytical tools make it possible to better integrate landscape patterns with behavioral processes. We show how resource selection functions can be used to describe habitat suitability with continuous and multivariable metrics and review methods by which animal movement can be quantified, analyzed, and modeled. We then show how the processes of habitat selection and movement can be integrated with landscape features using least-cost paths, graph theory, and step selection functions. These tools offer new ways to design, implement, and study corridors as landscape linkages more objectively and holistically.
Annual Review of Ecology, Evolution, and Systematics - Tập 37 Số 1 - Trang 317-342 - 2006
Biodiversity and Litter Decomposition in Terrestrial Ecosystems ▪ Abstract We explore empirical and theoretical evidence for the functional significance of plant-litter diversity and the extraordinary high diversity of decomposer organisms in the process of litter decomposition and the consequences for biogeochemical cycles. Potential mechanisms for the frequently observed litter-diversity effects on mass loss and nitrogen dynamics include fungi-driven nutrient transfer among litter species, inhibition or stimulation of microorganisms by specific litter compounds, and positive feedback of soil fauna due to greater habitat and food diversity. Theory predicts positive effects of microbial diversity that result from functional niche complementarity, but the few existing experiments provide conflicting results. Microbial succession with shifting enzymatic capabilities enhances decomposition, whereas antagonistic interactions among fungi that compete for similar resources slow litter decay. Soil-fauna diversity manipulations indicate that the number of trophic levels, species identity, and the presence of keystone species have a strong impact on decomposition, whereas the importance of diversity within functional groups is not clear at present. In conclusion, litter species and decomposer diversity can significantly influence carbon and nutrient turnover rates; however, no general or predictable pattern has emerged. Proposed mechanisms for diversity effects need confirmation and a link to functional traits for a comprehensive understanding of how biodiversity interacts with decomposition processes and the consequences of ongoing biodiversity loss for ecosystem functioning.
Annual Review of Ecology, Evolution, and Systematics - Tập 36 Số 1 - Trang 191-218 - 2005
The Evolution of Polyandry: Sperm Competition, Sperm Selection, and Offspring Viability ▪ Abstract In contrast to Bateman's principle, there is now increasing evidence that female fitness can depend on the number of mates obtained. A number of genetic benefits have been proposed for the evolution of polyandry. A meta-analysis of available data suggests that polyandry, rather than multiple mating, can have a weak but significant general effect on embryo viability, as indicated by egg hatching success. Although this effect is generally regarded as evidence in favor of the genetic incompatibility hypothesis, appropriate data that test for intrinsic sire effects on embryo viability are generally unavailable. Moreover, maternal effects that could generate the result have not been adequately controlled, and there is little unequivocal evidence to suggest that fertilization is biased toward sperm bearing genotypes that would enhance offspring viability. Greater effort is required in these areas to elucidate the mechanisms underlying observed fitness effects of polyandry.
Annual Review of Ecology, Evolution, and Systematics - Tập 36 Số 1 - Trang 125-146 - 2005
New Pathways and Processes in the Global Nitrogen Cycle Our understanding of the players and pathways of the global nitrogen cycle has advanced substantially over recent years with discoveries of several new groups of organisms and new types of metabolism. This review focuses on recently discovered processes that add new functionality to the nitrogen cycle and on the organisms that perform these functions. The processes include denitrification and other dissimilatory nitrogen transformations in eukaryotes, anaerobic ammonium oxidation, and anaerobic methane oxidation with nitrite. Of these, anaerobic ammonium oxidation coupled to nitrite reduction by anammox bacteria has been well documented in natural environments and constitutes an important sink for fixed nitrogen. Benthic foraminifera also contribute substantially to denitrification in some sediments, in what potentially represents an ancestral eukaryotic metabolism. The ecophysiology of the novel organisms and their interactions with classical types of nitrogen metabolism are important for understanding the nitrogen cycle and its tight links to the cycling of carbon today, in the past, and in the future.
Annual Review of Ecology, Evolution, and Systematics - Tập 43 Số 1 - Trang 407-428 - 2012
The Ecological Physiology of Earth's Second Oxygen Revolution Living animals display a variety of morphological, physiological, and biochemical characters that enable them to live in low-oxygen environments. These features and the organisms that have evolved them are distributed in a regular pattern across dioxygen (O2 ) gradients associated with modern oxygen minimum zones. This distribution provides a template for interpreting the stratigraphic covariance between inferred Ediacaran-Cambrian oxygenation and early animal diversification. Although Cambrian oxygen must have reached 10–20% of modern levels, sufficient to support the animal diversity recorded by fossils, it may not have been much higher than this. Today's levels may have been approached only later in the Paleozoic Era. Nonetheless, Ediacaran-Cambrian oxygenation may have pushed surface environments across the low, but critical, physiological thresholds required for large, active animals, especially carnivores. Continued focus on the quantification of the partial pressure of oxygen (pO2 ) in the Proterozoic will provide the definitive tests of oxygen-based coevolutionary hypotheses.
Annual Review of Ecology, Evolution, and Systematics - Tập 46 Số 1 - Trang 215-235 - 2015
Kin Selection and the Evolutionary Theory of Aging Researchers are increasingly recognizing that social effects influence the evolution of aging. Kin selection theory provides a framework for analyzing such effects because an individual's longevity and mortality schedule may alter its inclusive fitness via effects on the fitness of relatives. Kin-selected effects on aging have been demonstrated both by models of intergenerational transfers of investment by caregivers and by spatially explicit population models with limited dispersal. They also underlie coevolution between the degree and form of sociality and patterns of aging. In this review I critically examine and synthesize theory and data concerning these processes. I propose a classification, stemming from kin selection theory, of social effects on aging and describe a hypothesis for kin-selected conflict over parental time of death in systems with resource inheritance. I conclude that systematically applying kin selection theory to the analysis of the evolution of aging adds considerably to our general understanding of aging.
Annual Review of Ecology, Evolution, and Systematics - Tập 38 Số 1 - Trang 103-128 - 2007
Are Diseases Increasing in the Ocean? ▪ Abstract Many factors (climate warming, pollution, harvesting, introduced species) can contribute to disease outbreaks in marine life. Concomitant increases in each of these makes it difficult to attribute recent changes in disease occurrence or severity to any one factor. For example, the increase in disease of Caribbean coral is postulated to be a result of climate change and introduction of terrestrial pathogens. Indirect evidence exists that (a) warming increased disease in turtles; (b) protection, pollution, and terrestrial pathogens increased mammal disease; (c) aquaculture increased disease in mollusks; and (d) release from overfished predators increased sea urchin disease. In contrast, fishing and pollution may have reduced disease in fishes. In other taxa (e.g., sea grasses, crustaceans, sharks), there is little evidence that disease has changed over time. The diversity of patterns suggests there are many ways that environmental change can interact with disease in the ocean.
Annual Review of Ecology, Evolution, and Systematics - Tập 35 Số 1 - Trang 31-54 - 2004
Sympatric Speciation: Models and Empirical Evidence Sympatric speciation, the evolution of reproductive isolation without geographic barriers, remains highly contentious. As a result of new empirical examples and theory, it is now generally accepted that sympatric speciation has occurred in at least a few instances, and is theoretically plausible. Instead, debate has shifted to whether sympatric speciation is common, and whether models’ assumptions are generally met in nature. The relative frequency of sympatric speciation will be difficult to resolve, because biogeographic changes have obscured geographical patterns underlying many past speciation events. In contrast, progress is being made on evaluating the empirical validity of key theoretical conditions for sympatric speciation. Disruptive selection and direct selection on mating traits, which should facilitate sympatric speciation, are biologically well supported. Conversely, costs to assortative mating are also widely documented, but inhibit speciation. Evaluating the joint incidence of these key factors may illuminate why sympatric speciation appears to be relatively uncommon.
Annual Review of Ecology, Evolution, and Systematics - Tập 38 Số 1 - Trang 459-487 - 2007
Assisted Gene Flow to Facilitate Local Adaptation to Climate Change Assisted gene flow (AGF) between populations has the potential to mitigate maladaptation due to climate change. However, AGF may cause outbreeding depression (especially if source and recipient populations have been long isolated) and may disrupt local adaptation to nonclimatic factors. Selection should eliminate extrinsic outbreeding depression due to adaptive differences in large populations, and simulations suggest that, within a few generations, evolution should resolve mild intrinsic outbreeding depression due to epistasis. To weigh the risks of AGF against those of maladaptation due to climate change, we need to know the species' extent of local adaptation to climate and other environmental factors, as well as its pattern of gene flow. AGF should be a powerful tool for managing foundation and resource-producing species with large populations and broad ranges that show signs of historical adaptation to local climatic conditions.
Annual Review of Ecology, Evolution, and Systematics - Tập 44 Số 1 - Trang 367-388 - 2013
Some Evolutionary Consequences of Being a Tree Trees do not form a natural group but share attributes such as great size, longevity, and high reproductive output that affect their mode and tempo of evolution. In particular, trees are unique in that they maintain high levels of diversity while accumulating new mutations only slowly. They are also capable of rapid local adaptation and can evolve quickly from nontree ancestors, but most existing tree lineages typically experience low speciation and extinction rates. We discuss why the tree growth habit should lead to these seemingly paradoxical features.
Annual Review of Ecology, Evolution, and Systematics - Tập 37 Số 1 - Trang 187-214 - 2006
Tổng số: 17
- 1
- 2