Eco-evolutionary Dynamics

Author: Andrew P. Hendry

Publisher: Princeton University Press

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Category: Science

Page: 416

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In recent years, scientists have realized that evolution can occur on timescales much shorter than the "long lapse of ages" emphasized by Darwin—in fact, evolutionary change is occurring all around us all the time. This book provides an authoritative and accessible introduction to eco-evolutionary dynamics, a cutting-edge new field that seeks to unify evolution and ecology into a common conceptual framework focusing on rapid and dynamic environmental and evolutionary change. Andrew Hendry covers key aspects of evolution, ecology, and their interactions. Topics range from natural selection, adaptive divergence, ecological speciation, and gene flow to population and community dynamics, ecosystem function, plasticity, and genomics. Hendry evaluates conceptual and methodological approaches, and draws on empirical data from natural populations—including those in human-disturbed environments—to tackle a number of classic and emerging research questions. He also discusses exciting new directions for future research at the intersection of ecology and evolution. An invaluable guide for students and researchers alike, Eco-evolutionary Dynamics reveals how evolution and ecology interact strongly on short timescales to shape the world we see around us.

Eco-Evolutionary Dynamics

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Publisher: Academic Press

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Category: Science

Page: 392

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The theme of this volume is to discuss Eco-evolutionary Dynamics. Updates and informs the reader on the latest research findings Written by leading experts in the field Highlights areas for future investigation

Eco-evolutionary Dynamics, Density-dependent Dispersal and Collective Behaviour: Implications for Salmon Metapopulation Robustness

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Abstract : The spatial dispersal of individuals plays an important role in the dynamics of populations, and is central to metapopulation theory. Dispersal provides connections within metapopulations, promoting demographic and evolutionary rescue, but may also introduce maladapted individuals, potentially lowering the fitness of recipient populations through introgression of heritable traits. To explore this dual nature of dispersal, we modify a well-established eco-evolutionary model of two locally adapted populations and their associated mean trait values, to examine recruiting salmon populations that are connected by density-dependent dispersal, consistent with collective migratory behaviour that promotes navigation. When the strength of collective behaviour is weak such that straying is effectively constant, we show that a low level of straying is associated with the highest gains in metapopulation robustness and that high straying serves to erode robustness. Moreover, we find that as the strength of collective behaviour increases, metapopulation robustness is enhanced, but this relationship depends on the rate at which individuals stray. Specifically, strong collective behaviour increases the presence of hidden low-density basins of attraction, which may serve to trap disturbed populations, and this is exacerbated by increased habitat heterogeneity. Taken as a whole, our findings suggest that density-dependent straying and collective migratory behaviour may help metapopulations, such as in salmon, thrive in dynamic landscapes. Given the pervasive eco-evolutionary impacts of dispersal on metapopulations, these findings have important ramifications for the conservation of salmon metapopulations facing both natural and anthropogenic contemporary disturbances. This article is part of the theme issue 'Collective movement ecology'.

Eco-evolutionary Dynamics of Invasion in the Exotic Grass Bromus Rubens L.

Author: Matthew Ryan O'Neill

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Category: Bromegrasses

Page: 134

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A minority of exotic plant species undergo differentiation in vigor following introduction, leading to an explosion in population sizes and aggressive range expansion. Investigations into the mechanisms that determine successful invasion historically emphasized phenotypic traits in hopes of identifying ecological predictors and subsequent control mechanisms. Yet, it is now recognized that post-introductory evolution of invasiveness is common in many systems, frustrating efforts to identify ecological predictors. This suggests that evolutionary mechanisms ought to be given increased consideration. But this does not mean that regional differences in ecological interactions are unimportant. Many investigations demonstrate that invasive plant species experience facilitation in introduced relative to native range soils. My objective was to integrate these two promising fields of study in order to obtain a more holistic view of the mechanisms underlying invasion. Here I utilized seed and soils from native and introduced regions of the locally abundant grass species Bromus rubens L. (Pavlick and Anderson 2007, = B. madritensis ssp. rubens, Fortune et al. 2008), also known as Red brome. B. rubens is a winter annual common in the Mediterranean (native range) and Southwestern United States (introduced range). I examined the complexities of potential evolutionary and ecological factors leading to the invasion success of this species by concentrating on 1) patterns and promoters of regional differentiation, 2) the impacts of differentiation on competitive ability, and 3) the contribution of multiple ecological factors to plant-soil interactions. I found that introduced populations showed a strong signal for diversifying selection toward more aggressive growth. In a competitive environment introduced genotypes demonstrated greater reproductive fitness relative to native genotypes, regardless of competitor's genotypic or region of origin. Finally, a plant-soil interaction growth assay suggested that increased resource availability coupled with decreased interactions with both antagonistic and beneficial soil fungi in introduced soils contributed to the invasion success in B. rubens. Together these patterns indicate that the occurrence of post-introductory evolution is of major importance to the development of invasive characters and increased competitive ability, and that ecological interactions among hosts and respective soil communities greatly contributed to the dynamics observed in this system.

Dispersal Ecology and Evolution

Author: Jean Clobert

Publisher: Oxford University Press

ISBN:

Category: Science

Page: 462

View: 212

Provides a timely and wide-ranging overview of the fast expanding field of dispersal ecology, incorporating the very latest research. The causes, mechanisms, and consequences of dispersal at the individual, population, species, and community levels are considered.

Community Ecology

Author: Gary G. Mittelbach

Publisher: Oxford University Press, USA

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Page: 432

View: 869

Community ecology has undergone a transformation in recent years, from a discipline largely focused on processes occurring within a local area to a discipline encompassing a much richer domain of study, including the linkages between communities separated in space (metacommunity dynamics), niche and neutral theory, the interplay between ecology and evolution (eco-evolutionary dynamics), and the influence of historical and regional processes in shaping patterns of biodiversity. To fully understand these new developments, however, students continue to need a strong foundation in the study of species interactions and how these interactions are assembled into food webs and other ecological networks. This new edition fulfils the book's original aims, both as a much-needed up-to-date and accessible introduction to modern community ecology, and in identifying the important questions that are yet to be answered. This research-driven textbook introduces state-of-the-art community ecology to a new generation of students, adopting reasoned and balanced perspectives on as-yet-unresolved issues. Community Ecology is suitable for advanced undergraduates, graduate students, and researchers seeking a broad, up-to-date coverage of ecological concepts at the community level.

Spatial Vs. Non-spatial Eco-evolutionary Dynamics in a Tumor Growth Model

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Highlights: Cancer is an evolutionary spatial game in which different cell types compete for resources to proliferate and survive. This paper analyzes a spatial game of metastatic castrate-resistant prostate cancer (mCRPC). For almost all case studies the predictions of the spatial model differ from those of a nonspatial one. Non-spatial cancer models might be insufficient for capturing key elements of tumorigenesis. Abstract: Metastatic prostate cancer is initially treated with androgen deprivation therapy (ADT). However, resistance typically develops in about 1 year – a clinical condition termed metastatic castrate-resistant prostate cancer (mCRPC). We develop and investigate a spatial game (agent based continuous space) of mCRPC that considers three distinct cancer cell types: (1) those dependent on exogenous testosterone ( T + ), (2) those with increased CYP17A expression that produce testosterone and provide it to the environment as a public good ( T P ), and (3) those independent of testosterone ( T − ). The interactions within and between cancer cell types can be represented by a 3×3 matrix. Based on the known biology of this cancer there are 22 potential matrices that give roughly three major outcomes depending upon the absence (good prognosis), near absence or high frequency (poor prognosis) of T − cells at the evolutionarily stable strategy (ESS). When just two cell types coexist the spatial game faithfully reproduces the ESS of the corresponding matrix game. With three cell types divergences occur, in some cases just two strategies coexist in the spatial game even as a non-spatial matrix game supports all three. Discrepancies between the spatial game and non-spatial ESS happen because different cell types become more or less clumped in the spatial game – leading to non-random assortative interactions between cell types. Three key spatial scales influence the distribution and abundance of cell types in the spatial game: i. Increasing the radius at which cells interact with each other can lead to higher clumping of each type, ii. Increasing the radius at which cells experience limits to population growth can cause densely packed tumor clusters in space, iii. Increasing the dispersal radius of daughter cells promotes increased mixing of cell types. To our knowledge the effects of these spatial scales on eco-evolutionary dynamics have not been explored in cancer models. The fact that cancer interactions are spatially explicit and that our spatial game of mCRPC provides in general different outcomes than the non-spatial game might suggest that non-spatial models are insufficient for capturing key elements of tumorigenesis.