How Wolves Turned into Dogs and How Dogs Are Valuable in Meeting Human Social Needs

A wealth of recent behavioral, neurobiological, and genetic results allows us to draw a new, comprehensive picture of the human-wolf- dog relationship. Dogs originated from wolves 35,000 years ago, mainly via selection for tameness. Wolves were probably spiritual partners and hunting buddies of Paleolithic hunter-gatherers over wide areas of Eurasia. Coming together and staying together was probably facilitated by the close ecological and social match between wolves and humans. Both are cursorial hunters and scavengers living in cooperative but relatively closed family groups, which selected for very similar mentalities. Parallel selection for tameness (i.e., being “nice”) in dogs and humans quickly and in a diverse way changed behavioral and anatomical phenotypes from wolf to dog, and social orientation from Stone Age to modern humans. Actually, dogs were the most important human companions in conquering the world. By adapting to the needs of diverse human societies and civilizations, a wide variety of dogs developed. Over long periods of history dogs were meant to be benign with their own humans, but not with strangers. Hence human ingroup-outgroup distinctions may explain why considerable aggressiveness may still be found in dogs and humans, although incompatible today with a globalized world and universal ethics. In dogs this can be easily controlled by selective breeding and in humans, less easily, by cognition. Actually, sledge dogs and modern hunting breeds were selected for tolerance in the past. Most recent scientific results not only underline how closely dogs match human operational and social needs, but also find that most of the dog’s social behavior, cognition, and cooperativeness is direct wolf heritage and did not emerge in domestication, as previously thought. Dogs have adjusted to human needs in many subtle ways in the course of domestication. This makes dogs much better companions than tame wolves. Dogs are more easily socialized; they are strongly tuned toward people, respect human leadership, and are superior receivers and donors of emotional social support. Dogs actually became more obedient and respectful of social hierarchies than wolves, more dependent on human support, and better at inhibiting their impulses. Dogs diversified their barking for communicating with humans. They can read our emotions and adjust to them in an empathic way. Dogs are capable of human-like thinking, of taking a human perspective, and even of tricking us. Not least, they share a sense of fairness with wolves and humans. Hence, dogs can be particularly valuable partners in meeting universal human social needs. Human-dog relationships are “essentialized,” lacking the cultural and symbolic complexities of relationships between humans. But the devotion of dogs is not unconditional; they do judge our moods and social conduct and make their choices accordingly. Dogs can boost the self-esteem and agency of their human partners and are excellent “social lubricants,” thereby connecting people. Actually, in their flexibility, social devotion, adaptiveness, and responsiveness, dogs are the stars among all animal companions. No wonder, as the human-dog relationship started in the early Paleolithic, tens of thousands of years before the domestication of other animals. Dog companionship seems increasingly important in a globalized and digitalized world. An ever accelerating pace of life may not always provide the conditions needed to keep people physically and mentally healthy. Living in good relationships with dogs can keep people connected with their social essentials. Therefore, dogs are prime animal assistants in a wide range of activities, pedagogy, and therapy. Supported by human biophilia, the presence of a friendly dog may have strong calming and socializing effects on humans and may support communication and sociopositive behavior. Dogs are probably the most socially responsive of all companion animals, privately and in professional settings. In all such activities (for definitions please see the White Paper of the International Association of Human-Animal Interaction Organizations [IAHAIO], Jegatheesan et al., 2014), well-socialized and friendly dogs respond well to temporary and positive challenges, but must never be overburdened. It requires a suitable dog in a secure relationship with a sensitive and knowledgeable human partner. Furthermore, it has to be kept in mind that dog partners need regular veterinarian checks in the interest of the animals’ health and welfare and to minimize health risks (e.g., zoonoses) for the human partners. All activities and work need to conform to the IAHAIO Guidelines for Animal-Assisted Activities and Animal-Assisted Therapy (Prague, 1998) and with the IAHAIO White Paper (Jegatheesan et al., 2014)

A longitudinal study of dominance and aggression in greylag geese (Anser anser)

A variety of factors are known to affect dominance and aggression in social vertebrates. In the present study, we used a long-term data set on greylag geese (Anser anser) to investigate the complex relationships between individual life histories, the social environment, and dominance-related behaviors. We applied a multifactorial approach to assess the relative importance of factors in different life-history stages. Previous studies in geese documented effects of sex and social status and achieved differing results for the effects of family size, age, and body weight on dominance and aggression. Extrinsic factors like season or flock structure were generally not considered. Our analyses showed that a considerable number of factors related to individual life histories, season, and the social environment affected dominance and aggression in greylag geese, but not all significant effects were necessarily strong effects. Pronounced effects on aggression rates were caused by the flock's sex ratio, parental effects, individual social status, and sex. Whether individuals interacted with the same opponents repeatedly was influenced most by parental effects and the sex ratio, whereas the strongest determinants of dominance rank were parental effects and social status. Hence, dominance behaviors may not only be influenced by intrinsic factors but also by season and an individual's social environment. Furthermore, our study indicates that optimal choices for achieving or maintaining a high dominance rank may vary considerably between life-history stages. This highlights the value of long-term studies and multifactorial approaches for understanding the complexities of dominance relationships in social vertebrate

Life-stage specific environments in a cichlid fish: Implications for inducible maternal effects

Through environmentally induced maternal effects females may fine-tune their offspring's phenotype to the conditions offspring will encounter after birth. If juvenile and adult ecologies differ, the conditions that mothers experienced as juveniles may better predict their offspring's environment than the adult females' ambient conditions. Maternal effects induced by the environment experienced by females during their early ontogeny should evolve when three ecological conditions are met: (i) Adult ecology does not predict the postnatal environmental conditions of offspring; (ii) Environmental conditions for juveniles are correlated across successive generations; and (iii) Juveniles occasionally settle in conditions that differ from the juvenile habitat of their mothers. By combining size-structured population counts, ecological surveys and a genetic analysis of population structure we provide evidence that all three conditions hold for Simochromis pleurospilus, a cichlid fish in which mothers adjust offspring quality to their own juvenile ecology. Adults of many species cannot predict offspring's environment from ambient cues. Hence we predict that life-stage specific maternal effects are common in animals. Therefore, it is important to incorporate parental ontogeny in the study of parental effects when juveniles and adults inhabit different environments

Free-living greylag geese adjust their heart rates and body core temperatures to season and reproductive context

Animals adaptively regulate their metabolic rate and hence energy expenditure over the annual cycle to cope with energetic challenges. We studied energy management in greylag geese. In all geese, profound seasonal changes of heart rate (fH) and body temperature (Tb) showed peaks in summer and troughs during winter, and also daily modulation of fH and Tb. Daily mean fH was on average 22% lower at the winter trough than at the summer peak, whereas daily mean Tb at the winter trough was only about 1 °C below the summer peak. Daily means of Tb together with those of air temperature and day length were the most important predictors of daily mean fH, which was further modulated by precipitation, reproductive state, and, to a minor degree, social rank. Peaks of fH and Tb occurred earlier in incubating females compared to males. Leading goslings increased daily mean fH. Our results suggest that in greylag geese, pronounced changes of fH over the year are caused by photoperiod-induced changes of endogenous heat production. Similar to large non-hibernating mammals, tolerance of lower Tb during winter seems the major factor permitting this. On top of these major seasonal changes, fH and Tb are elevated in incubating females

Life-stage specific environments in a cichlid fish: implications for inducible maternal effects

Through environmentally induced maternal effects females may fine-tune their offspring's phenotype to the conditions offspring will encounter after birth. If juvenile and adult ecologies differ, the conditions mothers experienced as juveniles may better predict their offspring's environment than the adult females' conditions. Maternal effects induced by the environment experienced by females during their early ontogeny should evolve when three ecological conditions are met: (1) Adult ecology does not predict the postnatal environmental conditions of offspring; (2) Environmental conditions for juveniles are correlated across successive generations; and (3) Juveniles occasionally settle in conditions that differ from the juvenile habitat of their mothers. By combining size-structured population counts, ecological surveys and a genetic analysis of population structure we provide evidence that all three conditions hold for Simochromis pleurospilus, a cichlid fish in which mothers adjust offspring quality to their own juvenile ecology. In particular we show (1) that the spatial niches and the habitat quality differ between juveniles and adults, and we provide genetic evidence (2) that usually fish of successive generations grow up in similar habitats, and (3) that occasional dispersal in populations with a different habitat quality is likely to occur. As adults of many species cannot predict their offspring's environment from ambient cues, life-stage specific maternal effects are likely to be common in animals. It will therefore be necessary to incorporate parental ontogeny in the study of parental effects when juveniles and adults inhabit different environment

Аденокарцинома и полипы эндометрия в постменопаузальном возрасте: баланс цитокинов, продукция SFAS-лиганда и противорецидивная терапия

ЦИТОКИНЫЛИГАНДЫАДЕНОКАРЦИНОМАПОСТМЕНОПАУЗ

Recipients Affect Prosocial and Altruistic Choices in Jackdaws, Corvus monedula

Other-regarding preferences are a critical feature of human cooperation but to what extent non-human animals exhibit these preferences is a matter of intense discussion. We tested whether jackdaws show prosocial behaviour (providing benefits to others at no cost to themselves) and altruism (providing benefits to others while incurring costs) with both sibling and non-sibling recipients. In the prosocial condition, a box was baited on both the actor's and the recipient's side (1/1 option), whereas another box provided food only for the actor (1/0 option). In the altruistic condition, the boxes contained food for either the actor (1/0 option) or the recipient (0/1 option). The proportion of selfish (1/0 option) and cooperative (1/1 and 0/1 option, respectively) actors' choices was significantly affected by the recipients' behaviour. If recipients approached the boxes first and positioned themselves next to the box baited on their side, trying to access the food reward (recipient-first trials), actors were significantly more cooperative than when the actors approached the boxes first and made their choice prior to the recipients' arrival (actor-first trials). Further, in recipient-first trials actors were more cooperative towards recipients of the opposite sex, an effect that was even more pronounced in the altruistic condition. Hence, at no cost to the actors, all recipients could significantly influence the actors' behaviour, whereas at high costs this could be achieved even more so by recipients of different sex. Local/stimulus enhancement is discussed as the most likely cognitive mechanism to account for these effects

Rearing-group size determines social competence and brain structure in a cooperatively breeding cichlid.

This is the author accepted manuscript. The final version is available from The University of Chicago Press for The American Society of Naturalists via http://dx.doi.org/10.1086/681636Social animals can greatly benefit from well-developed social skills. Because the frequency and diversity of social interactions often increase with the size of social groups, the benefits of advanced social skills can be expected to increase with group size. Variation in social skills often arises during ontogeny, depending on early social experience. Whether variation of social-group sizes affects development of social skills and related changes in brain structures remains unexplored. We investigated whether, in a cooperatively breeding cichlid, early group size (1) shapes social behavior and social skills and (2) induces lasting plastic changes in gross brain structures and (3) whether the development of social skills is confined to a sensitive ontogenetic period. Rearing-group size and the time juveniles spent in these groups interactively influenced the development of social skills and the relative sizes of four main brain regions. We did not detect a sensitive developmental period for the shaping of social behavior within the 2-month experience phase. Instead, our results suggest continuous plastic behavioral changes over time. We discuss how developmental effects on social behavior and brain architecture may adaptively tune phenotypes to their current or future environments.We acknowledge financial support from the Swiss National Science Foundation (31003A_133066 to B.T. and P2BEP3_155614 to S.F.), the Foundation Pierre Mercier, and the Austrian Science Fund (J 3304-B24 to A.K.

Evolutionary associations between host traits and parasite load: insights from Lake Tanganyika cichlids

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Parasite diversity and abundance (parasite load) vary greatly among host species. However, the influence of host traits on variation in parasitism remains poorly understood. Comparative studies of parasite load have largely examined measures of parasite species richness, and are predominantly based on records obtained from published data. Consequently, little is known about the relationships between host traits and other aspects of parasite load, such as parasite abundance, prevalence, and aggregation. Meanwhile, understanding of parasite species richness may be clouded by limitations associated with data collation from multiple independent sources. We conducted a field study of Lake Tanganyika cichlid fishes and their helminth parasites. Using a Bayesian phylogenetic comparative framework, we tested evolutionary associations between five key host traits (body size, gut length, diet breadth, habitat complexity, number of sympatric hosts) predicted to influence parasitism, together with multiple measures of parasite load. We find that the number of host species that a particular host may encounter due to its habitat preferences emerges as a factor of general importance for parasite diversity, abundance, and prevalence, but not parasite aggregation. In contrast, body size and gut size are positively related to aspects of parasite load within, but not between species. The influence of host phylogeny varies considerably among measures of parasite load, with the greatest influence exerted on parasite diversity. These results reveal that both host morphology and biotic interactions are key determinants of host-parasite associations, and that consideration of multiple aspects of parasite load is required to fully understand patterns in parasitism