Mathias Kölliker

Natural History Museum Basel

Maternal effects can induce adjustments in offspring phenotype to the environment experienced by the mother. Of particular interest is if mothers can programme their offspring to cope best under matching environmental conditions, but the evidence for such anticipatory maternal effects (AME) is limited. In this study, we manipulated experimentally t...

The genetic conflict between parents and their offspring is a cornerstone of kin selection theory and the gene-centred view of evolution, but whether it actually occurs in natural systems remains an open question. Conflict operates only if parenting is driven by genetic trade-offs between offspring performance and the parent's ability to raise addi...

1. Parental care increases the fitness of offspring at a cost to the parents in terms of residual reproductive success. This trade-off may be affected by ecology, life history and the social environment, which raises the question as to how these factors contribute to the evolution of parental care. Here, previous hypotheses concerning the evolution...

The social bond between parents and offspring is characterized by coadaptation and balance between altruistic and selfish tendencies. However, its underlying genetic mechanism remains poorly understood. Using transcriptomic screens in the subsocial European earwig, Forficula auricularia, we found the expression of more than 1600 genes associated wi...

Our understanding of the evolutionary stability of socially‐selected traits is dominated by sexual selection models originating with R. A. Fisher, in which genetic covariance arising through assortative mating can trigger exponential, runaway trait evolution. To examine whether non‐reproductive, socially‐selected traits experience similar dynamics—...

Studies on the evolution of cooperative behaviour are typically confined to understanding its adaptive value. It is equally essential, however, to understand its potential to evolve, requiring knowledge about the phenotypic consistency and genetic basis of cooperative behaviour. While previous observational studies reported considerably high herita...

Alternative life histories may be maintained in populations due to variation in the costs and benefits of the underlying strategies. In this study, potential costs of dispersal by flight were investigated as an alternative life-history strategy in the mountain-living chrysomelid beetle Oreina cacaliae. 2. In this species, previous mark–recapture st...

In mammals, the chemical profiles of individuals are complex and variable mixtures, and animals perceive information based on variation in the overall quality of these mixtures. A variety of compounds potentially involved in chemical communication have been characterized in the urine of different felid species, but little is known about the informa...

The costs of signalling are often expressed in terms of increased predation risk to the signaller; however, whether signalling predators also incur costs due to eavesdropping by prey and may attempt to reduce these costs is less well studied. In this study, we investigated whether there is a trade-off between intraspecific communication through sce...

Maternal effects can induce adjustments in offspring phenotype to the environment experienced by the mother. Of particular interest is if mothers can programme their offspring to cope best under matching environmental conditions, but the evidence for such anticipatory maternal effects (AME) is limited. In this study, we manipulated experimentally t...

I wrote this little commentary on retrospective power calculations more than 10 years ago in 2004. It is based on a few thoughts that arose due to an emerging discussion on power analysis in the evolutionary ecology literature. It never got published. After three rounds of submission with the most extreme differences in referee judgment I ever rece...

When females care for broods of mixed paternity, there is a threat of enhanced rivalry among offspring of different paternal lineages. This competition is against the best evolutionary interest of the female because she is equally related to all of her offspring and enhanced offspring competition would decrease her fitness. It was hypothesized earl...

1. The patterns of multiple paternity among the progeny of females are key properties of genetic mating systems. Female multiple mating should evolve due to direct or indirect benefits, but it may also partly be driven by the encounter rate with different potential mates. 2. In this study this hypothesis was experimentally tested in the European ea...

Organisms have to allocate limited resources among multiple life-history traits, which can result in physiological trade-offs, and variation in environ-mental conditions experienced during ontogeny can influence reproduction later in life. Food restriction may lead to an adaptive reallocation of the lim-ited resources among traits as a phenotypical...

Kin recognition is a key mechanism to direct social behaviours towards related individuals or avoid inbreeding depression. In insects, recognition is generally mediated by cuticular hydrocarbon (CHC) compounds, which are partly inherited from parents. However, in social insects, potential nepotistic conflicts between group members from different pa...

Scent-marking is widespread among mammals and has been observed in many felid species. Although the behaviour is well-described, little is known about its function in wild felid populations. We investigated patterns of scent-marking and its role in intra- and intersexual communication among resident and non-resident Eurasian lynx Lynx lynx by obser...

Benefits and costs of group living may be differentially influenced by kinship or familiarity and depend on context. For example, aggregation with kin may be costly in a mating context due to the risk of inbreeding, but beneficial in social interactions because it may reduce within-group competition. Research investigating aggregation behaviour in...

The European earwig (Forficula auricularia) is an established system for studies of sexual selection, social interactions and the evolution of parental care. Despite its scientific interest, little knowledge exists about the species at the genomic level, limiting the scope of molecular studies and expression analyses of genes of interest. To overco...

Abstract The evolutionary transition from solitary to social life is driven by direct and indirect fitness benefits of social interactions. Understanding the conditions promoting the early evolution of social life therefore requires identification of these benefits in nonderived social systems, such as animal families where offspring are mobile and...

Many insects raise their offspring on organic substrates or in the soil where microorganisms are abundant. Microbes may pose a serious threat to offspring development and survival by either decomposing food resources or directly infecting the offspring. Selection to cope with these effects may favor social defenses, for example, through forms of pa...

The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, o...

1. Natural diversity in forms of parental care 2. Origin and evolution of parental care 3. Evolutionary maintenance of parental care 4. Genetics and epigenetics of parental care 5. Sociality beyond family

Families with parental care show a parent-offspring conflict over the amount of parental investment. To date, the resolution of this conflict was modeled as being driven by either purely within-brood or between-brood competition. In reality the partitioning of parental resources within- versus between-broods is an evolving life history trait, which...

Parental care is beneficial for offspring, but costly for parents. Thus, it seems maladaptive to care for unrelated offspring unless the additional offspring provide direct benefits to the carer’s own offspring or discrimination costs are high. Females of the European earwig, Forficula auricularia, provide maternal care for their own offspring (nym...

Although inbreeding is commonly known to depress individual fitness, the severity of inbreeding depression varies considerably across species. Among the factors contributing to this variation, family interactions, life stage and sex of offspring have been proposed, but their joint influence on inbreeding depression remains poorly understood. Here,...

Benefits and costs of parental care are expected to change with offspring development and lead to age-dependent coadaptation expressed as phenotypic (behavioural) matches between offspring age and parental reproductive stage. Parents and offspring interact repeatedly over time for the provision of parental care. Their behaviours should be according...

In agricultural landscapes, the lack of floral nectar can be a major difficulty for nectar feeding parasitoids. This problem can be reduced by the addition of suitable wildflowers. To date, flowers have mainly been studied in terms of effects on parasitoid fitness, not taking into account the essential role of flower attractiveness for foraging par...

Social structures such as families emerge as outcomes of behavioural interactions among individuals, and can evolve over time if families with particular types of social structures tend to leave more individuals in subsequent generations. The social behaviour of interacting individuals is typically analysed as a series of multiple dyadic (pair-wise...

Parental care includes a wide variety of traits that enhance offspring development and survival. It is taxonomically widespread and is central to the maintenance of biodiversity through its close association with other phenomena such as sexual selection, life-history evolution, sex allocation, sociality, cooperation and conflict, growth and develop...

The family is an arena for conflicts between offspring, mothers and fathers that need resolving to promote the evolution of parental care and the maintenance of family life. Co-adaptation is known to contribute to the resolution of parent-offspring conflict over parental care by selecting for combinations of offspring demand and parental supply tha...

Whether to reproduce once or multiple times (semelparity vs. iteroparity) is a major life-history decision that organisms have to take. Mode of parity is usually considered a species characteristic. However, recent models suggested that population properties or condition-dependent fitness payoffs could help to maintain both life-history tactics wit...

Parental care typically enhances offspring fitness at costs for tending parents. Asymmetries in genetic relatedness entail potential conflicts between parents and offspring over the duration and the amount of care. To understand how these conflicts are resolved evolutionarily, it is important to understand how individual condition affects offspring...

The aggregation of parents with offspring is generally associated with different forms of care that improve offspring survival at potential costs to parents. Under poor environments, the limited amount of resources available can increase the level of competition among family members and consequently lead to adaptive changes in parental investment....

Hydrocarbons are a ubiquitous component of the insect exo-skeleton (cuticle). Their primary function is to provide an effec-tive hydrophobic barrier against water loss and desiccation. But cuticular hydrocarbons (CHCs) are also species-specific, vary with the biotic and abiotic environment, and they have been shown to often have evolved a secondary...

In group-living or social species intraspecific predation and cannibalism can lead to substantial decreases in inclusive fitness because related individuals may encounter one another. Therefore, selection on the ability and accuracy of kin recognition to avoid losses in inclusive fitness is expected. Competition and relatedness are two key factors...

Mock et al. (2011) in the following referred to as ''MDS'', point out some weaknesses and inconsistencies in begging re-search, and they convincingly place signaling of need (Godfray, 1991) and signaling of quality (Grafen, 1990) at eye level as 2 competing hypotheses for the evolution of off-spring begging signals. Hopefully, the 2 hypotheses will...

Solicitation signals by offspring are well known to influence parental behaviour, and it is commonly assumed that this behavioural effect translates into an effect on residual reproduction of parents. However, this equivalence assumption concerning behavioural and reproductive effects caused by offspring signals remains largely untested. Here, we t...

Parent–offspring conflict theory predicts the evolution of offspring solicitation signals that can influence the amount and/or the duration of parental investment. Short-term effects of offspring solicitation signals on parental food provisioning have been widely demonstrated, but persistent effects of offspring signals on the maintenance of parent...

Consistent inter-individual variation in behaviour over time and across contexts has been reported for a wide variety of animals, a phenomenon commonly referred to as personality. As behavioural patterns develop inside families, rearing conditions could have lasting effects on the expression of adult personality. In species with parental care, conf...

Aggression levels among individuals can severely increase under high density or shortage of crucial resources, sometimes resulting in individuals killing conspecifics. This is not uncommon in family groups of diverse taxa, where the dependent offspring compete for the limited resources provided by their parents. Killing a nest mate can relax the le...

In species across taxa, offspring have means to influence parental investment (PI). PI thus evolves as an interacting phenotype and indirect genetic effects may strongly affect the co-evolutionary dynamics of offspring and parental behaviors. Evolutionary theory focused on explaining how exaggerated offspring solicitation can be understood as resol...

Theory for the evolution of social interactions based on continuous strategies often assumes for simplicity that expressed behaviours are independent of previous encounters. In reality, however, such dependencies are likely to be widespread and often strong, generating complex behavioural dynamics. To model this process and illustrate potential con...

Begging signals of offspring are condition-dependent cues that are usually predicted to display information about the short-term need (i.e. hunger) to which parents respond by allocating more food. However, recent models and experiments have revealed that parents, depending on the species and context, may respond to signals of quality (i.e. offspri...

Viele Organismen leben zumindest phasenweise in sozialen Verbänden, in denen Altruismus und Kooperation herrschen, aber auch Konflikte ausgetragen werden. Für Darwin war die Evolution von Sozialverhalten eine spezielle und nicht vollständig lösbare Herausforderung. Heute ist es ein etabliertes Gebiet der Evolutionsbiologie. Darwins Evolutionstheori...

The evolution of the complex and dynamic behavioural interactions between caring parents and their dependent offspring is a major area of research in behavioural ecology and quantitative genetics. While behavioural ecologists examine the evolution of interactions between parents and offspring in the light of parent-offspring conflict and its resolu...

The occurrence of parental food regurgitation as a form of parental care in (sub-) social insects has been little studied and is largely based on anectodal and indirect evidence. However, understanding the behavioural mechanisms mediating the benefit of parental care is critical to advance research on the evolution of family interactions. Here, we...

Posthatching maternal care such as food provisioning and protection has evolved several times in insects, allowing offspring (larvae, nymphs) to interact with their mothers and potentially influence their investment. The evolutionary conflict over the duration and amount of parental care is thought to promote the evolution of offspring begging beha...

The distribution of food among altricial bird nestlings is the result of an interaction between parental feeding decisions and scramble competition between nestmates. Both young and parents can potentially be in control of the outcome of this interaction. In great tits, each parent feeds from a fixed location on the nest rim, thereby forcing nestli...

Sibling and parent–offspring conflicts arise mainly over the amount and distribution of parental care, especially food. In altricial bird species where the young depend on parents for obtaining food, parents may control sibling competition by the choice of their respective provisioning locations. In great tits, the parents use fixed provisioning po...

The evolution of parental care and family group formation critically depends on offspring survival benefits and parental fecundity costs of care under given ecological conditions. Investigations of the functional significance of care in insect species that exhibit facultative parental care have been relatively rare but may be of particular interest...

Abstract 1. Understanding the evolution of subsocial behaviour and parental care requires experimental tests of the functional significance of such behaviours and the role of tending parents in the maintenance of family groups. Studies in subsocial insects addressing these issues experimentally and in the field are still relatively rare. 2. In such...

The sensory modalities used for communication among family members have at least partly evolved within an organism's pre-existing sensory context. Given the well-known general importance of chemical communication in insects, we hypothesized in sub-social insects with parental care that chemical signals emitted by larvae to influence parental care (...

The evolution of parent-offspring interactions for the provisioning of care is usually explained as the phenotypic outcome of resolved conflicting selection pressures. However, parental care and offspring solicitation are expected to have complex patterns of inheritance. Here we present a quantitative genetic model of parent-offspring interactions...

When your variables of interest are distributed on a circle (e.g., angles, times of day, dates) linear statistics often cannot be used properly. The major problem with circular variables is that values which are far apart on a linear scale can be very close together in reality. Take for example an angle of 10 degree. On a linear scale, it is 340 de...

Female burrower bugs (Sehirus cinctus, Hemiptera: Cydnidae) show extended care for their offspring. They guard their clutch and feed the hatched nymphs up to the third larval instar. Previous research indicated that nymphs partly regulate maternal food provisioning, but how nymphs accomplish this is unknown. We tested the hypothesis that nymphs sol...

When ontogeny takes place in a family, and parents provide essential resources for development, the parents become an environmental component to the development of a wide range of offspring traits. Because differences among parents may partly reflect genetic variation, this environmental component contains genes and may itself evolve. Also, when of...

Parent birds often feed from predictable sites at the nest and nestlings compete for access to positions close to them. Such scrambling for stable parentally favoured positions may relate to optimal foraging theory. For efficient foraging, nestlings should be able to associate begging payoffs with the available positions in the nestcup and use this...

The most commonly used modelling methods for targeting customers in direct marketing are artificial neural networks (ANNs), classification trees (CTs) and logistic regression (LR). These methods differ in how rules for the association between purchase behaviour and customer information are derived from the data. The authors investigated the predict...

Evolutionary models for the resolution of family conflicts are sensitive to assumptions regarding the behavioural mechanisms regulating parental resource provisioning and offspring begging. Thus, quantitative empirical estimates of the mechanisms are critical to validate current evolutionary models, but a standardized method is lacking. I present a...

The most commonly used modelling methods for targeting customers in direct marketing are artificial neural networks (ANNs), classification trees (CTs) and logistic regression (LR). These methods differ in how rules for the association between purchase behaviour and customer information are derived from the data. The authors investigated the predict...

Carotenoids cannot be synthesized by birds and thus have to be ingested with food, suggesting that carotenoid-based plumage coloration is environmentally determined. However signaling functions ascribed to plumage imply that plumage coloration is the outcome of an evolutionary process based on genetic variation. By means of a cross-fostering design...

— Carotenoids cannot be synthesized by birds and thus have to be ingested with food, suggesting that ca-rotenoid-based plumage coloration is environmentally determined. However signaling functions ascribed to plumage imply that plumage coloration is the outcome of an evolutionary process based on genetic variation. By means of a cross-fostering des...

Evolutionary theory of parent-offspring conflict explains begging displays of nestling birds as selfish attempts to influence parental food allocation. Models predict that this conflict may be resolved by honest signaling of offspring need to parents, or by competition among nestmates, leading to escalated begging scrambles. Although the former typ...