scholarly journals An Assessment of Population Size and Demographic Drivers of the Bearded Vulture Using Integrated Population Models

2020 ◽  
Vol 101 (3) ◽  
Author(s):  
Antoni Margalida ◽  
José Jiménez ◽  
José M. Martínez ◽  
José A. Sesé ◽  
Diego García‐Ferré ◽  
...  
Keyword(s):  
Population Size ◽  
Population Models ◽  
Bearded Vulture

An assessment of population size and demographic drivers of the Bearded Vulture using integrated population models

2020 ◽  
Vol 90 (3) ◽  
Author(s):  
Antoni Margalida ◽  
José Jiménez ◽  
José M. Martínez ◽  
José A. Sesé ◽  
Diego García‐Ferré ◽  
...  
Keyword(s):  
Population Size ◽  
Population Models ◽  
Bearded Vulture

scholarly journals A Revisit of Infinite Population Models for Evolutionary Algorithms on Continuous Optimization Problems

2020 ◽  
Vol 28 (1) ◽  
pp. 55-85
Author(s):  
Bo Song ◽  
Victor O.K. Li
Keyword(s):  
Population Dynamics ◽  
Evolutionary Algorithms ◽  
Population Size ◽  
Optimization Problems ◽  
Continuous Optimization ◽  
Analytical Framework ◽  
Population Models ◽  
Initial Population ◽  
Infinite Population ◽  
Continuous Optimization Problems

Infinite population models are important tools for studying population dynamics of evolutionary algorithms. They describe how the distributions of populations change between consecutive generations. In general, infinite population models are derived from Markov chains by exploiting symmetries between individuals in the population and analyzing the limit as the population size goes to infinity. In this article, we study the theoretical foundations of infinite population models of evolutionary algorithms on continuous optimization problems. First, we show that the convergence proofs in a widely cited study were in fact problematic and incomplete. We further show that the modeling assumption of exchangeability of individuals cannot yield the transition equation. Then, in order to analyze infinite population models, we build an analytical framework based on convergence in distribution of random elements which take values in the metric space of infinite sequences. The framework is concise and mathematically rigorous. It also provides an infrastructure for studying the convergence of the stacking of operators and of iterating the algorithm which previous studies failed to address. Finally, we use the framework to prove the convergence of infinite population models for the mutation operator and the [Formula: see text]-ary recombination operator. We show that these operators can provide accurate predictions for real population dynamics as the population size goes to infinity, provided that the initial population is identically and independently distributed.

scholarly journals A Simulation Study on Increasing Capture Periods in Bayesian Closed Population Capture-Recapture Models with Heterogeneity

2020 ◽  
Vol 18 (1) ◽  
pp. 2-23
Author(s):  
Ross M. Gosky ◽  
Joel Sanqui
Keyword(s):  
Population Size ◽  
Simulation Study ◽  
Simulated Data ◽  
Population Models ◽  
Data Set ◽  
Closed Population ◽  
Population Sizes ◽  
Capture Recapture

Capture-Recapture models are useful in estimating unknown population sizes. A common modeling challenge for closed population models involves modeling unequal animal catchability in each capture period, referred to as animal heterogeneity. Inference about population size N is dependent on the assumed distribution of animal capture probabilities in the population, and that different models can fit a data set equally well but provide contradictory inferences about N. Three common Bayesian Capture-Recapture heterogeneity models are studied with simulated data to study the prevalence of contradictory inferences is in different population sizes with relatively low capture probabilities, specifically at different numbers of capture periods in the study.

Weak convergence to the coalescent in neutral population models

1999 ◽  
Vol 36 (2) ◽  
pp. 446-460 ◽  
Author(s):  
M. Möhle
Keyword(s):  
Weak Convergence ◽  
Population Size ◽  
Large Class ◽  
Total Population ◽  
Population Models ◽  
Total Population Size ◽  
Hitting Probabilities ◽  
Time Scaling ◽  
Convergence Behaviour ◽  
Or Genes

For a large class of neutral population models the asymptotics of the ancestral structure of a sample of n individuals (or genes) is studied, if the total population size becomes large. Under certain conditions and under a well-known time-scaling, which can be expressed in terms of the coalescence probabilities, weak convergence in DE([0,∞)) to the coalescent holds. Further the convergence behaviour of the jump chain of the ancestral process is studied. The results are used to approximate probabilities which are of certain interest in applications, for example hitting probabilities.

The time back to the most recent common ancestor in exchangeable population models

2004 ◽  
Vol 36 (01) ◽  
pp. 78-97 ◽  
Author(s):  
M. Möhle
Keyword(s):  
Population Size ◽  
Common Ancestor ◽  
Large Population ◽  
Upper Bounds ◽  
Population Models ◽  
Recent Common Ancestor ◽  
Coalescent Theory ◽  
Expected Time ◽  
Most Recent Common Ancestor ◽  
Haploid Population

A class of haploid population models with population size N, nonoverlapping generations and exchangeable offspring distribution is considered. Based on an analysis of the discrete ancestral process, we present solutions, algorithms and strong upper bounds for the expected time back to the most recent common ancestor which hold for arbitrary sample size n ∈ {1,…,N}. New insights into the asymptotic behaviour of the expected time back to the most recent common ancestor for large population size are presented relating the results to coalescent theory.

Introduction to Population Models

2021 ◽  
pp. 25-46
Author(s):  
Timothy E. Essington
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Population Size ◽  
Population Models ◽  
Change Model ◽  
Density Dependent ◽  
Intrinsic Factors ◽  
Model Understanding ◽  
Dynamics Of Populations ◽  
Simple Models

The chapter “Introduction to Population Models” introduces unstructured population models and shows how model decisions can change model behavior, the different ways that feedbacks can be represented, and how one evaluates the consequences of those feedbacks. The goal here is to show how modeling a single entity, population density, can be done in many different ways, depending on the purpose of the model. Understanding the dynamics of populations remains one of the fundamental goals of ecology. Not surprisingly, many models have contributed to the theory of population dynamics and regulation. The models vary considerably in terms of depth, breadth, intended uses (e.g. prediction vs. generality), and structure. This chapter will largely focus on the behavior of simple models, to see how intrinsic factors can dictate variability in population size. Density-independent and density-dependent models are covered, as well as methods used to understand model behaviors.

Modified Leslie–DeLury Population Models of the Long-Finned Pilot Whale (Globicephala melaena) and Annual Production of the Short-Finned Squid (Illex illecebrosus) Based upon their Interaction at Newfoundland

1975 ◽  
Vol 32 (7) ◽  
pp. 1145-1154 ◽  
Author(s):  
M. C. Mercer
Keyword(s):  
Population Size ◽  
Closed System ◽  
Population Models ◽  
Annual Production ◽  
Initial Population ◽  
Pilot Whale ◽  
Seasonal Movements ◽  
System Models ◽  
Initial Population Size ◽  
Pilot Whales

Distributions and seasonal movements of Globicephala melaena and Illex illecebrosus evince similar patterns and the cetacean feeds almost exclusively on the cephalopod while inshore at Newfoundland. Peaks in Newfoundland landings of both species are coincident and this is taken to indicate that availability of pilot whales inshore depends on that of short-finned squid. Progressively higher peaks in squid landings with progressively lower peaks in whale landings are interpreted to indicate depletion of the whale populations. Utilizing squid landings as a correction for availability of whales, closed system models are generated to estimate the initial population size of the exploited pilot whales at less than 60,000. Estimates of potential squid consumption by these stocks indicate that annual squid production may be in the order of several hundred thousand tons.

Coalescent results for two-sex population models

1998 ◽  
Vol 30 (2) ◽  
pp. 513-520 ◽  
Author(s):  
M. Möhle
Keyword(s):  
Population Size ◽  
Population Models ◽  
Fisher Model

‘Convergence-to-the-coalescent’ theorems for two-sex neutral population models are presented. For the two-sex Wright-Fisher model the ancestry of n sampled genes behaves like the usual n-coalescent, if the population size N is large and if the time is measured in units of 4N generations. Generalisations to a larger class of two-sex models are discussed.

A convergence theorem for markov chains arising in population genetics and the coalescent with selfing

1998 ◽  
Vol 30 (2) ◽  
pp. 493-512 ◽  
Author(s):  
M. Möhle
Keyword(s):  
Population Genetics ◽  
Markov Chains ◽  
Population Size ◽  
Mutation Rate ◽  
Convergence Theorem ◽  
Population Models ◽  
Fisher Model

A simple convergence theorem for sequences of Markov chains is presented in order to derive new ‘convergence-to-the-coalescent’ results for diploid neutral population models.For the so-called diploid Wright-Fisher model with selfing probability s and mutation rate θ, it is shown that the ancestral structure of n sampled genes can be treated in the framework of an n-coalescent with mutation rate ̃θ := θ(1-s/2), if the population size N is large and if the time is measured in units of (2-s)N generations.

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