scholarly journals Towards a predictive conservation biology: the devil is in the behaviour

2019 ◽  
Vol 374 (1781) ◽  
pp. 20190013 ◽  
Author(s):  
Bernt-Erik Sæther ◽  
Steinar Engen
Keyword(s):  
Population Dynamics ◽  
Genetic Drift ◽  
Conservation Biology ◽  
Evolutionary Dynamics ◽  
Behavioural Ecology ◽  
Demographic Stochasticity ◽  
Factors Affecting ◽  
Bateman Gradient ◽  
Theoretical Evidence ◽  
Population Viability Analyses

One of the most important challenges in conservation biology is to predict the viability of populations of vulnerable and threatened species. This requires that the demographic stochasticity strongly affecting the ecological and evolutionary dynamics of especially small populations is correctly estimated and modelled. Here, we summarize theoretical evidence showing that the demographic variance in population dynamics is a key parameter determining the probability of extinction and also is directly linked to the magnitude of the genetic drift in the population. The demographic variance is dependent on the mating system, being larger in a polygynous than in monogamous populations. Understanding factors affecting intersexual differences in mating success is therefore essential in explaining variation in the demographic variance. We hypothesize that the strength of sexual selection, for example, quantified by the Bateman gradient, may be a useful predictor of the magnitude of the demographic stochasticity and hence the genetic drift in the population. We provide results from a field study of moose that support this claim. Thus, including central principles from behavioural ecology may increase the reliability of population viability analyses through an improvement of our understanding of factors affecting stochastic influences on population dynamics and evolutionary processes. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.

Genetics in conservation and wildlife management: a revolution since Caughley

2009 ◽  
Vol 36 (1) ◽  
pp. 70 ◽  
Author(s):  
Stephen D. Sarre ◽  
Arthur Georges
Keyword(s):  
Conservation Biology ◽  
Wildlife Management ◽  
Driving Forces ◽  
Model Organisms ◽  
Demographic Stochasticity ◽  
Introduced Predators ◽  
Genetic Technologies ◽  
Theoretical Evidence ◽  
Sound Management ◽  
The Impact

In his 1994 review of conservation biology, Graeme Caughley questioned the central role for genetics in that discipline. His central theme was that there was no known case of genetic malfunction leading to the extinction of a population or species, and that driving forces such as overkill, habitat fragmentation and introduced predators as well as environmental and demographic stochasticity of small populations should be considered ahead of genetics in the debate about extinction prevention. At the time, only indirect and theoretical evidence existed for genetic contributions to the declines of wildlife and most of the debate revolved around the impact of genetic variation on fitness and long-term persistence. In addition, the application of DNA technologies to the study of wildlife was in its infancy. Though this was not Caughley’s intention, many within wildlife management took his criticisms of genetic aspects of species decline as the cue to dismiss this branch of science as of minor relevance to conservation biology. Since Caughley’s critique, there has been a revolution in genetic technologies for non-model organisms with the arrival of highly informative hypervariable DNA markers. Perhaps even more importantly, developments in DNA and gene technologies have provided the opportunity to study fundamental life-history traits such as disease resistance in more direct ways than previously possible. In concert with these tools, conservation geneticists have risen to Caughley’s challenge and demonstrated unambiguously a clear role for genetic analysis in conservation biology. Despite these impressive advances, there remains an important gap between the genetic approaches available and their uptake by managers. Bridging this gap will greatly increase the capacity of wildlife managers to generate the data necessary for sound management.

Population dynamics and conservation biology of the over-exploited Mediterranean red coral

2007 ◽  
Vol 244 (3) ◽  
pp. 416-423 ◽  
Author(s):  
Giovanni Santangelo ◽  
Lorenzo Bramanti ◽  
Mimmo Iannelli
Keyword(s):  
Population Dynamics ◽  
Conservation Biology ◽  
Red Coral

scholarly journals Population Dynamics Based on Resource Availability & Founding Effects: Live & Computational Models

2016 ◽  
Vol 78 (5) ◽  
pp. 396-403 ◽  
Author(s):  
Samuel Potter ◽  
Rebecca M. Krall ◽  
Susan Mayo ◽  
Diane Johnson ◽  
Kim Zeidler-Watters ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Computer Literacy ◽  
Computational Models ◽  
Computational Simulation ◽  
School Science ◽  
Simulation Software ◽  
High School Science ◽  
Initial Population ◽  
College Level ◽  
Factors Affecting

With the looming global population crisis, it is more important now than ever that students understand what factors influence population dynamics. We present three learning modules with authentic, student-centered investigations that explore rates of population growth and the importance of resources. These interdisciplinary modules integrate biology, mathematics, and computer-literacy concepts aligned with the Next Generation Science Standards. The activities are appropriate for middle and high school science classes and for introductory college-level biology courses. The modules incorporate experimentation, data collection and analysis, drawing conclusions, and application of studied principles to explore factors affecting population dynamics in fruit flies. The variables explored include initial population structure, food availability, and space of the enclosed population. In addition, we present a computational simulation in which students can alter the same variables explored in the live experimental modules to test predictions on the consequences of altering the variables. Free web-based graphing (Joinpoint) and simulation software (NetLogo) allows students to work at home or at school.

scholarly journals Polygenic local adaptation in metapopulations: a stochastic eco-evolutionary model

2020 ◽  
Author(s):  
Enikő Szép ◽  
Himani Sachdeva ◽  
Nick Barton
Keyword(s):  
Population Size ◽  
Local Adaptation ◽  
Genetic Drift ◽  
Diffusion Approximation ◽  
Joint Distribution ◽  
Evolutionary Model ◽  
Ecological Niches ◽  
Demographic Stochasticity ◽  
Linkage Disequilibria ◽  
Population Sizes

AbstractThis paper analyses the conditions for local adaptation in a metapopulation with infinitely many islands under a model of hard selection, where population size depends on local fitness. Each island belongs to one of two distinct ecological niches or habitats. Fitness is influenced by an additive trait which is under habitat-dependent directional selection. Our analysis is based on the diffusion approximation and accounts for both genetic drift and demographic stochasticity. By neglecting linkage disequilibria, it yields the joint distribution of allele frequencies and population size on each island. We find that under hard selection, the conditions for local adaptation in a rare habitat are more restrictive for more polygenic traits: even moderate migration load per locus at very many loci is sufficient for population sizes to decline. This further reduces the efficacy of selection at individual loci due to increased drift and because smaller populations are more prone to swamping due to migration, causing a positive feedback between increasing maladaptation and declining population sizes. Our analysis also highlights the importance of demographic stochasticity, which exacerbates the decline in numbers of maladapted populations, leading to population collapse in the rare habitat at significantly lower migration than predicted by deterministic arguments.

scholarly journals The Dynamics of Influenza A H3N2 Defective Viral Genomes from a Human Challenge Study

2019 ◽  
Author(s):  
Michael A. Martin ◽  
Drishti Kaul ◽  
Gene S. Tan ◽  
Christopher W. Woods ◽  
Katia Koelle
Keyword(s):  
Genetic Drift ◽  
Influenza A ◽  
Evolutionary Dynamics ◽  
De Novo ◽  
Gene Segment ◽  
Influenza Viruses ◽  
Genomic Variation ◽  
Wild Type Virus ◽  
Single Nucleotide Variants ◽  
Viral Genomes

AbstractThe rapid evolution of influenza is an important contributing factor to its high worldwide incidence. The emergence and spread of genetic point mutations has been thoroughly studied both within populations and within individual hosts. In addition, influenza viruses are also known to generate genomic variation during their replication in the form of defective viral genomes (DVGs). These DVGs are formed by internal deletions in at least one gene segment that render them incapable of replication without the presence of wild-type virus. DVGs have previously been identified in natural human infections and may be associated with less severe clinical outcomes. These studies have not been able to address how DVG populations evolve in vivo in individual infections due to their cross-sectional design. Here we present an analysis of DVGs present in samples from two longitudinal influenza A H3N2 human challenge studies. We observe the generation of DVGs in almost all subjects. Although the genetic composition of DVG populations was highly variable, identical DVGs were observed both between multiple samples within single hosts as well as between hosts. Most likely due to stochastic effects, we did not observe clear instances of selection for specific DVGs or for shorter DVGs over the course of infection. Furthermore, DVG presence was not found to be associated with peak viral titer or peak symptom scores. Our analyses highlight the diversity of DVG populations within a host over the course of infection and the apparent role that genetic drift plays in their population dynamics.ImportanceThe evolution of influenza virus, in terms of single nucleotide variants and the reassortment of gene segments, has been studied in detail. However, influenza is known to generate defective viral genomes (DVGs) during replication, and little is known about how these genomes evolve both within hosts and at the population level. Studies in animal models have indicated that prophylactically or therapeutically administered DVGs can impact patterns of disease progression. However, the formation of naturally-occurring DVGs, their evolutionary dynamics, and their contribution to disease severity in human hosts is not well understood. Here, we identify the formation of de novo DVGs in samples from human challenge studies throughout the course of infection. We analyze their evolutionary trajectories, revealing the important role of genetic drift in shaping DVG populations during acute infections with well-adapted viral strains.

scholarly journals Ecological and evolutionary dynamics of interconnectedness and modularity

2018 ◽  
Vol 115 (4) ◽  
pp. 750-755 ◽  
Author(s):  
Jan M. Nordbotten ◽  
Simon A. Levin ◽  
Eörs Szathmáry ◽  
Nils C. Stenseth
Keyword(s):  
Population Dynamics ◽  
Natural Selection ◽  
Evolution Equation ◽  
Evolutionary Dynamics ◽  
Population Distribution ◽  
Theoretical Framework ◽  
Ecological System ◽  
Macro Level ◽  
Population Distributions ◽  
Trait Space

In this contribution, we develop a theoretical framework for linking microprocesses (i.e., population dynamics and evolution through natural selection) with macrophenomena (such as interconnectedness and modularity within an ecological system). This is achieved by developing a measure of interconnectedness for population distributions defined on a trait space (generalizing the notion of modularity on graphs), in combination with an evolution equation for the population distribution. With this contribution, we provide a platform for understanding under what environmental, ecological, and evolutionary conditions ecosystems evolve toward being more or less modular. A major contribution of this work is that we are able to decompose the overall driver of changes at the macro level (such as interconnectedness) into three components: (i) ecologically driven change, (ii) evolutionarily driven change, and (iii) environmentally driven change.

Applications to conservation biology

2019 ◽  
pp. 247-265
Author(s):  
Louis W. Botsford ◽  
J. Wilson White ◽  
Alan Hastings
Keyword(s):  
Frequency Spectrum ◽  
Conservation Biology ◽  
Pacific Salmon ◽  
Population Viability ◽  
Population Parameters ◽  
Replacement Rate ◽  
Different Populations ◽  
Probability Of Extinction ◽  
Population Viability Analyses

This chapter describes how models can aid in managing populations to prevent extinction, given uncertainty about their state. From previous chapters, it is clear that avoiding extinction requires keeping both abundance and the replacement rate high. However, for both, the question remains, how high? The question of how high abundance should be to achieve a certain risk is addressed by existing population viability analyses (PVA). By contrast, the problem of maintaining high replacement has received little attention. This chapter describes how uncertainty in population parameters and the frequency spectrum of the environment both affect estimates of the probability of extinction, including examples of PVAs that pay greater attention to those complications. Additionally, an example is provided of tracking both abundance and replacement to avoid extinction for many different populations of a single taxon, Pacific salmon. Finally, the role of portfolio effects (diversity in variance among populations) is explored.

Heritability, polymorphism, and population dynamics: individual-based eco-evolutionary simulations

2021 ◽  
pp. 329-340
Author(s):  
Anna Kuparinen
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Evolutionary Dynamics ◽  
Atlantic Cod ◽  
Population Projections ◽  
Phenotypic Traits ◽  
Evolutionary Changes ◽  
Future Challenges ◽  
Evolutionary Simulations ◽  
Main Message

Contemporary evolution that occurs across ecologically relevant time scales, such as a few generations or decades, can not only change phenotypes but also feed back to demographic parameters and the dynamics of populations. This chapter presents a method to make phenotypic traits evolve in mechanistic individual-based simulations. The method is broadly applicable, as demonstrated through its applications to boreal forest adaptation to global warming, eco-evolutionary dynamics driven by fishing-induced selection in Atlantic cod, and the evolution of age at maturity in Atlantic salmon. The main message of this chapter is that there may be little reason to exclude phenotypic evolution in analyses of population dynamics, as these can be modified by evolutionary changes in life histories. Future challenges will be to integrate rapidly accumulating genomic knowledge and an ecosystem perspective to improve population projections and to better understand the drivers of population dynamics.

scholarly journals Late Pleistocene climate change and population dynamics of Japanese Myodes voles inferred from mitochondrial cytochrome b sequences

2019 ◽  
Vol 100 (4) ◽  
pp. 1156-1168 ◽  
Author(s):  
Asuka Honda ◽  
Shota Murakami ◽  
Masashi Harada ◽  
Kimiyuki Tsuchiya ◽  
Gohta Kinoshita ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Cytochrome B ◽  
Late Pleistocene ◽  
Evolutionary Dynamics ◽  
Glacial Maximum ◽  
Rapid Expansion ◽  
Historical Background ◽  
Mitochondrial Cytochrome ◽  
Genetic Structuring ◽  
Mitochondrial Cytochrome B

Abstract The Japanese archipelago is comprised of four main islands—Hokkaido, Honshu, Shikoku, and Kyushu—which contain high mountainous areas that likely allowed for lineage differentiation and population genetic structuring during the climatic changes of the late Pleistocene. Here, we assess the historical background of the evolutionary dynamics of herbivorous red-backed voles (Myodes) in Japan, examining the evolutionary trends of mitochondrial cytochrome b gene (Cytb) sequence variation. Four apparent signals from rapid expansion events were detected in three species, M. rufocanus and M. rutilus from Hokkaido and M. smithii from central Honshu. Taken together with results from previous studies on Japanese wood mice (Apodemus spp.), three of the expansion events were considered to be associated with predicted bottleneck events at the marine isotope stage (MIS) 4 period, in which glaciers are thought to have expanded extensively, especially at higher elevations. In the late Pleistocene, the possible candidates are transitions MIS 6/5, MIS 4/3, and MIS 2/1, which can be characterized by the cold periods of the penultimate glacial maximum, MIS 4, and the last glacial maximum, respectively. Our data further reveal the genetic footprints of repeated range expansion and contraction in the northern and southern lineages of the vole species currently found in central Honshu, namely M. andersoni and M. smithii, in response to climatic oscillation during the late Pleistocene. The time-dependent evolutionary rates of the mitochondrial Cytb presented here would provide a possible way for assessing population dynamics of cricetid rodents responding to the late Pleistocene environmental fluctuation.

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