Evidence of Site-Specific and Male-Biased Germline Mutation Rate in a Wild Songbird.

Germline mutations are the ultimate source of genetic variation and the raw material for organismal evolution. Despite their significance, the frequency and genomic locations of mutations, as well as potential sex bias, are yet to be widely investigated in most species. To address these gaps, we conducted whole-genome sequencing of 12 great reed warblers (Acrocephalus arundinaceus) in a pedigree spanning 3 generations to identify single-nucleotide de novo mutations (DNMs) and estimate the germline mutation rate.

Solar heating may explain extreme diel flight altitude changes in migrating birds.

Great reed warblers, Acrocephalus arundinaceus, and great snipes, Gallinago media, exhibit a diel cycle in flight altitudes-flying much higher during the day than the night-when performing migratory flights covering both night and day. One hypothesis proposed to explain this behavior is that the birds face additional heating by solar radiation during daytime and hence must climb to very high, and thus also very cold, altitudes to avoid overheating during daytime flights. Yet, solar heat gain in birds has been shown to drastically decrease with wind speed, and the quantitative heating effect by solar radiation on a bird flying with an airspeed of 10 m/s or more is unknown.

Heritability and Parental Effects in Telomere Length in a Color Polymorphic Long-Lived Bird.

AbstractRelative telomere length (RTL), an indicator of senescence, has been shown to be heritable but can also be affected by environmental factors, such as parental effects. Investigating heritability as well as parental effects and rearing environment can help us to understand the factors affecting offspring telomeres. Moreover, how phenotypic parental traits linked with fitness can impact offspring RTL is still unclear.

Telomeres in ecology and evolution: A review and classification of hypotheses.

Research on telomeres in the fields of ecology and evolution has been rapidly expanding over the last two decades. This has resulted in the formulation of a multitude of, often name-given, hypotheses related to the associations between telomeres and life-history traits or fitness-facilitating processes (and the mechanisms underlying them). However, the differences (or similarities) between the various hypotheses, which can originate from different research fields, are often not obvious.

Avian Neo-Sex Chromosomes Reveal Dynamics of Recombination Suppression and W Degeneration.

How the avian sex chromosomes first evolved from autosomes remains elusive as 100 million years (My) of divergence and degeneration obscure their evolutionary history. The Sylvioidea group of songbirds is interesting for understanding avian sex chromosome evolution because a chromosome fusion event ∼24 Ma formed "neo-sex chromosomes" consisting of an added (new) and an ancestral (old) part. Here, we report the complete female genome (ZW) of one Sylvioidea species, the great reed warbler (Acrocephalus arundinaceus).

Extreme altitudes during diurnal flights in a nocturnal songbird migrant.

Billions of nocturnally migrating songbirds fly across oceans and deserts on their annual journeys. Using multisensor data loggers, we show that great reed warblers () regularly prolong their otherwise strictly nocturnal flights into daytime when crossing the Mediterranean Sea and the Sahara Desert. Unexpectedly, when prolonging their flights, they climbed steeply at dawn, from a mean of 2394 meters above sea level to reach extreme cruising altitudes (mean 5367 and maximum 6267 meters above sea level) during daytime flights.

A genome-wide linkage map for the house sparrow (Passer domesticus) provides insights into the evolutionary history of the avian genome.

The house sparrow is an important model species for studying physiological, ecological and evolutionary processes in wild populations. Here, we present a medium density, genome wide linkage map for house sparrow (Passer domesticus) that has aided the assembly of the house sparrow reference genome, and that will provide an important resource for ongoing mapping of genes controlling important traits in the ecology and evolution of this species. Using a custom house sparrow 10 K iSelect Illumina SNP chip we have assigned 6,498 SNPs to 29 autosomal linkage groups, based on a mean of 430 informative meioses per SNP.

Adaptive responses of animals to climate change are most likely insufficient.

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive.

Sex differences in life history, behavior, and physiology along a slow-fast continuum: a meta-analysis.

The pace-of-life syndrome (POLS) hypothesis predicts that behavior and physiology covary with life history. Evidence for such covariation is contradictory, possibly because systematic sources of variation (e.g.

Evidence for sexual conflict over major histocompatibility complex diversity in a wild songbird.

Sex differences in parasite load and immune responses are found across a wide range of animals, with females generally having lower parasite loads and stronger immune responses than males. Intrigued by these general patterns, we investigated if there was any sign of sex-specific selection on an essential component of adaptive immunity that is known to affect fitness, the major histocompatibility complex class I (MHC-I) genes, in a 20-year study of great reed warblers. Our analyses on fitness related to MHC-I diversity showed a highly significant interaction between MHC-I diversity and sex, where males with higher, and females with lower, MHC-I diversity were more successful in recruiting offspring.

Contrasting results from GWAS and QTL mapping on wing length in great reed warblers.

A major goal in evolutionary biology is to understand the genetic basis of adaptive traits. In migratory birds, wing morphology is such a trait. Our previous work on the great reed warbler (Acrocephalus arundinaceus) shows that wing length is highly heritable and under sexually antagonistic selection.

Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms.

Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS.

Did natural selection make the Dutch taller? A cautionary note on the importance of quantification in understanding evolution.

One of the main achievements of the modern synthesis is a rigorous mathematical theory for evolution by natural selection. Combining this theory with statistical models makes it possible to estimate the relevant parameters so as to quantify selection and evolution in nature. Although quantification is a sign of a mature science, statistical models are unfortunately often interpreted independently of the motivating mathematical theory.

Maternal and genetic factors determine early life telomere length.

In a broad range of species--including humans--it has been demonstrated that telomere length declines throughout life and that it may be involved in cell and organismal senescence. This potential link to ageing and thus to fitness has triggered recent interest in understanding how variation in telomere length is inherited and maintained. However, previous studies suffer from two main drawbacks that limit the possibility of understanding the relative importance of genetic, parental and environmental influences on telomere length variation.

Assessing multivariate constraints to evolution across ten long-term avian studies.

Background: In a rapidly changing world, it is of fundamental importance to understand processes constraining or facilitating adaptation through microevolution. As different traits of an organism covary, genetic correlations are expected to affect evolutionary trajectories. However, only limited empirical data are available.

Intralocus sexual conflict over wing length in a wild migratory bird.

Intralocus sexual conflict (ISC) occurs when males and females have different adaptive peaks but are constrained from evolving sexual dimorphism because of shared genes. Implications of this conflict on evolutionary dynamics in wild populations have not been investigated in detail. In comprehensive analyses of selection, heritability, and genetic correlations, we found evidence for an ISC over wing length, a key trait for flight performance and migration, in a long-term study of wild great reed warblers (Acrocephalus arundinaceus).

Annual cycle and migration strategies of a trans-Saharan migratory songbird: a geolocator study in the great reed warbler.

Recent technological advancements now allow us to obtain geographical position data for a wide range of animal movements. Here we used light-level geolocators to study the annual migration cycle in great reed warblers (Acrocephalus arundinaceus), a passerine bird breeding in Eurasia and wintering in sub-Saharan Africa. We were specifically interested in seasonal strategies in routes and schedules of migration.

Hybridization but no evidence for backcrossing and introgression in a sympatric population of great reed warblers and clamorous reed warblers.

Hybridization is observed frequently in birds, but often it is not known whether the hybrids are fertile and if backcrossing occurs. The breeding ranges of the great reed warbler (Acrocephalus arundinaceus) and the clamorous reed warbler (A. stentoreus) overlap in southern Kazakhstan and a previous study has documented hybridization in a sympatric population.

A strong quantitative trait locus for wing length on chromosome 2 in a wild population of great reed warblers.

Wing length is a key character for essential behaviours related to bird flight such as migration and foraging. In the present study, we initiate the search for the genes underlying wing length in birds by studying a long-distance migrant, the great reed warbler (Acrocephalus arundinaceus). In this species wing length is an evolutionary interesting trait with pronounced latitudinal gradient and sex-specific selection regimes in local populations.

Postglacial colonisation patterns and the role of isolation and expansion in driving diversification in a passerine bird.

Pleistocene glacial cycles play a major role in diversification and speciation, although the relative importance of isolation and expansion in driving diversification remains debated. We analysed mitochondrial DNA sequence data from 15 great reed warbler (Acrocephalus arundinaceus) populations distributed over the vast Eurasian breeding range of the species, and revealed unexpected postglacial expansion patterns from two glacial refugia. There were 58 different haplotypes forming two major clades, A and B.

Estimating heritabilities and genetic correlations: comparing the 'animal model' with parent-offspring regression using data from a natural population.

Quantitative genetic parameters are nowadays more frequently estimated with restricted maximum likelihood using the 'animal model' than with traditional methods such as parent-offspring regressions. These methods have however rarely been evaluated using equivalent data sets. We compare heritabilities and genetic correlations from animal model and parent-offspring analyses, respectively, using data on eight morphological traits in the great reed warbler (Acrocephalus arundinaceus).