Telomere length reveals cumulative individual and transgenerational inbreeding effects in a passerine bird

Inbreeding results in more homozygous offspring that should suffer reduced fitness, but it can be difficult to quantify these costs for several reasons. First, inbreeding depression may vary with ecological or physiological stress and only be detectable over long time periods. Second, parental homozygosity may indirectly affect offspring fitness, thus confounding analyses that consider offspring homozygosity alone. Finally, measurement of inbreeding coefficients, survival and reproductive success may often be too crude to detect inbreeding costs in wild populations. Telomere length provides a more precise measure of somatic costs, predicts survival in many species and should reflect differences in somatic condition that result from varying ability to cope with environmental stressors. We studied relative telomere length in a wild population of Seychelles warblers (Acrocephalus sechellensis) to assess the lifelong relationship between individual homozygosity, which reflects genome-wide inbreeding in this species, and telomere length. In juveniles, individual homozygosity was negatively associated with telomere length in poor seasons. In adults, individual homozygosity was consistently negatively related to telomere length, suggesting the accumulation of inbreeding depression during life. Maternal homozygosity also negatively predicted offspring telomere length. Our results show that somatic inbreeding costs are environmentally dependent at certain life stages but may accumulate throughout life.</p

Supplement 1. Source code for simulations

File List scanning.tar.gz -- Compressed archive with the C source code files README -- Instructions for compilation and use Description This program 'xscanning' performs a given number of numerical integrations for the multispecies Droop model. The simulation parameters are described in the 'header.h' file, and can be modified there. These parameters include: BAND : the dominant band of the R-star matrix MAX : the number of species(=resources) RRANGE: the range from which the R-star values are chosen FRANGE: the range from which the F-hat values are chosen RUNS : the number of runs TIME : the number of days per run The program takes care of the generation of V, K, and Q matrices according to the rules described in Appendix A. The source code is written in ANSI-C and makes use of the GNU Scientific Library for numerical integration of ordinary differential equations http://www.gnu.org/software/gsl/. More details in the README file

Appendix A. Simulation details.

Simulation details

Appendix B. Parameter values.

Parameter values

Data from: The importance of mechanisms for the evolution of cooperation

Studies aimed at explaining the evolution of phenotypic traits have often solely focused on fitness considerations, ignoring underlying mechanisms. In recent years, there has been an increasing call for integrating mechanistic perspectives in evolutionary considerations, but it is not clear whether and how mechanisms affect the course and outcome of evolution. To study this, we compare four mechanistic implementations of two well-studied models for the evolution of cooperation, the Iterated Prisoner's Dilemma (IPD) game and the Iterated Snowdrift (ISD) game. Behavioural strategies are either implemented by a 1 : 1 genotype–phenotype mapping or by a simple neural network. Moreover, we consider two different scenarios for the effect of mutations. The same set of strategies is feasible in all four implementations, but the probability that a given strategy arises owing to mutation is largely dependent on the behavioural and genetic architecture. Our individual-based simulations show that this has major implications for the evolutionary outcome. In the ISD, different evolutionarily stable strategies are predominant in the four implementations, while in the IPD each implementation creates a characteristic dynamical pattern. As a consequence, the evolved average level of cooperation is also strongly dependent on the underlying mechanism. We argue that our findings are of general relevance for the evolution of social behaviour, pleading for the integration of a mechanistic perspective in models of social evolution.,Simulation dataThis file contains the output of 100 replicate simulations for each parameter setting of our study (both of the results presented in the main text and in the SI). The folders are named as follows: game_mutationrate_payoffconfiguration_behaviouralimplementation_mutationregime. The abbreviations stand for the following: IPD = Iterated Prioner's Dilemma game, ISD = Iterated Snowdrift game, NN = neural network, TM = 1:1 mapping, GM = entire-genome muation, LM = per-locus mutation. Each folder contains 100 .txt files with simulation output. Time is on the rows (top row is the first generation), the frequencies of the different strategies (in the same order as in table 2 of the main text) are on the columns.simulation_data.rar

Reference data from the Pathomove simulation, for the manuscript "Novel pathogen introduction rapidly alters the evolution of movement, restructuring animal societies"

This is a reference dataset of multiple runs of the 'Pathomove' simulation, to accompany the manuscript "Novel pathogen introduction rapidly alters the evolution of movement, restructuring animal societies". The datasets are in the form of R data objects saved as Rds files