The maintenance of ecologically significant genetic polymorphisms remains a challenging field within evolutionary ecology. I will present genetic, physiological, ethological, and behavioural ecological mechanisms involved in maintaining three behavioural male morphs and individually distinctive breeding plumage polymorphism in the ruff, Philomachus pugnax, a lekking sandpiper. I will concentrate on: behavioural mating tactics of male morphs based on field and captive studies, field estimates of annual morph-specific mating success, and factors maintaining equilibrium levels among morphs, including considerations of lek size, differential fitness of female morphs, and potential mate-specific sex allocation by females. I conclude that strong sexually antagonistic intralocus conflict is likely operating at the morph-determining inversion. [more]

Genomes vary in diversity within and among species. Even within diploid individuals, there are parts of the genomes that are characterized by high diversity (heterozygosity) and others that are more homozygous. It is the aim of this talk to discuss how such differences come about and are maintained in natural free-living populations. I will give a brief back ground on recombination and linkage disequilibrium. I will then describe a genomic region described as a recombinatiopn ‘hotspot‘ with examples of our studies of the MHC-region in the black grouse (Tetrao tetrix). Next I will discuss a recombination ‘coldspot‘: an inversion polymorphism (so called supergene) recently discovered in the ruff (Philomachus pugnax) which may explain the maintenance of the extraordinary behavioural polymorphism found in males of this species. I will end by relating our findings to other studies of supergenes and the maintenance of complex phenotypic traits. [more]

Sex ratio variation is a fundamental component of life history evolution. At conception, birth, and adulthood, the ratios of males to females have long been recognized by evolutionary biologists and human demographers as catalysts for social behaviour and population dynamics. Throughout human and wild animal populations, variation in the adult sex ratio is remarkable and has been shown to predict divorce, sexual aggression, and parental cooperation. Causality is unclear, but clues may become apparent through understanding the life history origins of the adult sex ratio. Join me as I attempt to unravel the demographic pathways that shape sex biases and assess their evolutionary consequences on parental and mating strategies. I will present recent results from a detailed demographic analysis across several species of Charadrius plover – a small ground-nesting shorebird found in a variety of ecosystems worldwide. Plovers exhibit a remarkable diversity in breeding behaviour: sex roles during courtship, mating, and parental care vary considerably among populations both between and within species. This behavioural variation, coupled with their extreme tractability in the field, allow the opportunity to confidently explore the sources and significance of demographic sex-biases among wild populations in light of breeding system evolution. [more]

Aggression is an evolutionary conserved social behavior that is regulated by both environment and genetics. Understanding the neural and genetic basis of aggression is a major challenge in neurobiology especially since the extent of environmental and genetic contribution may vary between systems. A great deal of what we know about neurobiological differences in naturally occurring subordinate and dominant phenotypes comes from species in which social rank is reversible and based on the social environment. In this talk, I will present my previous work on Astatotilapia burtoni, an African cichlid with a socially controlled dominance hierarchy and well-characterized differences along the hypothalamic-pituitary-gonadal (HPG) axis. I will highlight differences between vasotocin and serotonin neurons in subordinate and dominant males and present a model for how their interactions could regulate aggression. With this background I will lead into my current research on the Ruff, Philomachus pugnax. In the Ruff, the evolution of a social system with three genetically determined male morphs was facilitated by an inversion event on an autosomal chromosome 3.8 million years ago. How did this chromosomal aberration lead to the distinct aggression profiles, mating strategies, breeding plumage and endocrinal profiles observed among the morphs? We are in a unique position to begin to answer these questions and discover neuroanatomical and gene expression differences across male morphs that will help us better understand their evolution. [more]

Conditions experienced early in life have long-term fitness consequences. Because in most taxa the early-life environment is provided by the parents, selection should favour increased parental care. Yet, considerable variation in parental provisioning is observed within and across populations. Life history theory predicts that this variation is maintained through parental costs associated with increased offspring provisioning. Yet, the proximate mechanisms underlying such fundamental life-history trade-offs remain poorly understood. To gain insights into the constraints and trade-off that shape the evolution of life history strategies, we artificially selected Japanese quail (Coturnix japonica) for divergent maternal egg provisioning, and explored costs, benefits and constraints at the genetic, transcriptomic and phenotypic level. In this talk I will show how different family members ‘like their eggs’ and provide evidence that the immune system plays a key role in mediating the trade-off between reproductive effort and lifespan. [more]

The eggs laid by birds come in an extraordinary variety of shapes, sizes, colors and textures, despite the fact that they serve the same essential function: to nourish and protect a chick until it hatches. To investigate the form and function of avian eggs, I use a multidisciplinary approach, drawing on tools from math, computer vision, bioengineering and genomics. In this talk, I will show how analyzing eggs has revealed surprising insights into avian evolution and behavior. Egg shape, for example, is correlated with flight behavior, and eggshell pigmentation patterns encode the details of a coevolutionary battle between cuckoos and hosts. Overall, natural selection has tugged the egg phenotype in multiple directions to fashion a structure that can meet diverse mechanical, thermoregulatory and signaling demands. [more]

The last decade has seen an unprecedented quest for genome regions involved in adaptation and speciation that was usually based on the assumption that such genome regions can be identified as ones exhibiting accentuated differentiation. In this presentation, I showcase how accumulating empirical evidence together with longstanding theory force us to reconsider such an approach. In particular, I illustrate how processes unrelated to adaptation or speciation may confound our quest for genomic regions underpinning adaptation and speciation, and argue that a comparative population genomics framework that exploits emergent features of long-term linked selection can help overcome shortcomings of traditional genome scans for adaptive evolution. [more]

Our planet finds itself in the sixth extinction crisis, this one being of an anthropogenic nature. In the NGS era, evolutionary biologists now have an opportunity to contribute to conservation with the help of genome wide data. In this presentation, I provide an overview of a number of Southeast Asian case studies in which the application of NGS based methodologies has contributed directly to species conservation and survival, including: (1) population-genomic assistance in ex-situ breeding of terminally endangered vertebrates; (2) detection of introgressive hybridization and genomic infiltration of foreign alleles in depleted populations; (3) inference of origin of traded individuals; and (4) discovery of significant cryptic diversity in an understudied fauna. Southeast Asia is one of the richest and – at the same time – one of the most anthropogenically impacted regions in the world, and shows the strongest beginnings of the impending extinction crisis. Conservation-genomics offers an increasingly affordable remedy for the lack of pertinent information on what to save and how to save it. [more]

CANCELLED --- CANCELLED - CANCELLED ---Despite significant recent progress in understanding mammalian evolution, the relationships among the various orders of placental mammals and the timing of their diversification in the geological past are still debated. We use a large dataset, containing genome-scale DNA sequences from representatives of all placental orders, to construct a well-supported mammalian phylogeny based on techniques that circumvent key biases rooted in properties of genomic data. Our results provide a resolution to some controversial questions about mammalian phylogeny, for example by showing that flying lemurs are closely related to primates. By utilizing our new phylogenetic tree in combination with 21 well-dated fossils that allow calibration of evolutionary rates, we infer that the radiation of placental orders occurred in a rapid episode spanning the Cretaceous-Paleogene (KPg) boundary. We therefore propose a new hypothesis, the trans-KPg burst model of placental diversification, which matches the mammalian fossil record more closely than previous “molecular clock” reconstructions. [more]

Complex phenotypes are determined by many genes and can well be investigated using network methods. Hence, to study the evolution of complex phenotypes, comparative network approaches are very promising. Here we aim to shed light on the evolution of cognitive abilities in humans. To this end, we used transcriptome data from pre-frontal cortex samples of humans, chimpanzees, and rhesus macaques to calculate transcription factor (TF) co-expression networks. We revealed an overall increase in connectivity on the human lineage and that several TFs that are known to be involved in brain development or cognitive disorders have turned into hubs specifically in the human networks. These TFs are good candidates for further experimental studies on the evolution of cognition. We developed several methods to facilitate comparative network analyses, among them a statistical framework to combine similar networks into consensus networks of high confidence, to assign p-values to links, and to define conserved, species-specific, and diverged links. Our methods are publicly available via two R packages, wTO and CoDiNA, and come along with sophisticated interactive visualization. We hope them to be useful for other evolutionary network studies. [more]

Complex phenotypes are determined by many genes and can well be investigated using network methods. Hence, tostudy the evolution of complex phenotypes, comparative network approaches are very promising. Here we aim to shedlight on the evolution of cognitive abilities in humans. To this end, we used transcriptome data from pre-frontal cortexsamples of humans, chimpanzees, and rhesus macaques to calculate transcription factor (TF) co-expression networks.We revealed an overall increase in connectivity on the human lineage and that several TFs that are known to be involvedin brain development or cognitive disorders have turned into hubs specifically in the human networks. These TFs aregood candidates for further experimental studies on the evolution of cognition.We developed several methods to facilitate comparative network analyses, among them a statistical framework tocombine similar networks into consensus networks of high confidence, to assign p-values to links, and to define conserved,species-specific, and diverged links. Our methods are publicly available via two R packages, wTO and CoDiNA, andcome along with sophisticated interactive visualization. We hope them to be useful for other evolutionary networkstudies. [more]

The conventional framework for the study of bird song is that males do the singing and females do the listening. Underthis scheme, sex-specific roles in signalling typically involve the advertisement of male quality on one hand, and femalechoice based on song content on the other. Although many studies proved that male attributes correlate with songperformance, the link between superior songs and mating success remains elusive. One potential explanation for thelack of a general applicability of the classical concept is that females’ role in the acoustic communication mediating thefunction and evolution of song is overly simplified therein. Accordingly, using field data from a European passerinespecies I will demonstrate how female quality can shape the song output of a male via within-individual plasticity andhow patterns of assortative/disassortative matings can rearrange rules for female choice. Moreover, relying on comparativedata from a large number of species, I will also show how sharpened competition for males can favour advertisementsongs in females in an evolutionary time scale. [more]

Despite significant recent progress in understanding mammalian evolution, the relationships among the various orders ofplacental mammals and the timing of their diversification in the geological past are still debated. We use a large dataset,containing genome-scale DNA sequences from representatives of all placental orders, to construct a well-supported mammalianphylogeny based on techniques that circumvent key biases rooted in properties of genomic data. Our results providea resolution to some controversial questions about mammalian phylogeny, for example by showing that flying lemursare closely related to primates. By utilizing our new phylogenetic tree in combination with 21 well-dated fossils that allowcalibration of evolutionary rates, we infer that the radiation of placental orders occurred in a rapid episode spanning theCretaceous-Paleogene (KPg) boundary. We therefore propose a new hypothesis, the trans-KPg burst model of placentaldiversification, which matches the mammalian fossil record more closely than previous “molecular clock” reconstructions. [more]

The white-throated sparrow (Zonotrichia albicollis) is an ordinary looking songbird with extraordinary genetics. Both sexes exist in either a white-striped or tan-striped morph, as determined by a >100-Mb inversion-based supergene on the second chromosome. White morph birds are almost all heterozygous for the supergene, suggesting that homozygousity is deleterious. Tan morph birds are homozygous without the supergene. The supergene is associated with a suite of coadapted traits that are expressed by both white males and females, including higher levels of aggressiveness, song and copulation, and lower levels of parental care. Due to behavioral and genetic incompatibilities within white male x white female pairs, white-throated sparrows pair dissassortively by morph. Tan males and white females share parental care relatively equally, whereas white males provide little paternal support to tan partners. We leveraged this unique system and an 18-year long-term dataset regarding reproduction and survivorship to test different evolutionary theories of aging, and elucidate how differences in actuarial and reproductive senescence might affect the balance in fitness between morphs. On one hand, some theories of aging suggest that competitive traits, such as those associated with the supergene, have high physiological costs and promote a live-fast-die-young strategy and faster senescence. On the other hand, intense investment in parental care, as in the tan morph, can also have costs. Furthermore, a more cooperative reproductive strategy, as observed in tan males x white femalepairs, might lessen reproductive costs and dampen senescence rates. Our data do not support high costs of the competitive traits associated with the morph-determining supergene, but rather suggest high costs of unsupported parental care, and that cooperative reproductive strategies might dampen rates of senescence. To better understand how genetics contribute to morph differences in life-history and senescence, more work is needed regarding how specific genes within the supergene affect physiological and self-maintenance differences between the morphs. Such work will ultimately advance understanding of how supergenes promote the persistence of multiple morphs with distinct life-history strategies within a species. [more]

The Norwegian Institute for Nature Research (NINA) is a private research institute with responsibility for monitoring of plants and animals of management interest in Norway: invasive species, harvested species, and red-listed species of conservation concern. Long-term ecological monitoring of these taxa requires efficient sampling methods that provide information on population trends and habitat requirements, while controlling for the problem of imperfect detection rates under field conditions. Occupancy models are a mark-recapture model based on repeated sampling that has the advantage that sampling can be based on detections of unmarked animals. Detections can be recorded with a variety of different kinds of sampling gear, including eDNA for freshwater species, Malaise traps for insects, den checks for mammals, or sound recordings for birds. I will introduce occupancy models and available software tools. To demonstrate the utility of occupancy models for ecological monitoring, I will discuss a variety of recent case studies where models based on single season sampling, multilevel sampling designs, and multiple detection states have provided insights into early detection of invasive species, and population trends and key ecological drivers for harvested populations and species of conservation concern in Norway. [more]