The traits of the behavior of sled dogs depending on their origin

A dog is a unique animal, capable of complex relationships not only with its relatives, but also with a man. Impulsivity is a behavioral trait described as the inability to postpone behavior in the presence of significant signals. The purpose of the work was to study the traits of the behavior of sled dogs depending on their origin. The studies have been carried out on dogs of the breeds of Siberian and Alaskan husky. The animals have been divided into groups: the 1st group Siberian husky (show type); the 2nd group – Siberian husky (sports type); the 3rd group – Alaskan husky. It has been found that Siberian husky of the show type and the Siberian husky of the sports type were indifferent to the shot (4,6 points). Alaskan husky dogs received a significantly lower score of 3,5 points (P > 0,95). According to the degree of excitability, the ratio of animal ratings in the studied groups was distributed as follows; the dogs of the 3rd group had the high degree of excitability, which received 2,8±0,09 points out of 3 possible points. Significantly lower scores of 2,0 and 2,2 were awarded to individuals of the 1st and 2nd groups (Siberian husky of show and sports types) with the significant difference of P > 0,999 and P > 0,95, respectively, in relation to animals of the 3rd group (Alaskan husky). For the 1st and 2nd groups of dogs, the average degree of excitability was more characteristic. While in the 3rd group there were no dogs with the low degree of excitability. The dogs of Siberian husky show-type did not show fear and fright towards a man. In the dogs of Siberian husky show type, the passive-defensive reaction was not expressed.

Tendency to laugh is a stable trait: Findings from a round-robin conversation study

Is the tendency to laugh a stable trait? What does the amount of laughter tell us about the personality and state of the producer, and how does their laughter influence the people around them? To answer these questions, we used a round-robin design where participants (N=66) engaged in 10 different conversations with 10 same-gender strangers. This design allowed us to determine state- and trait-level differences in how much people laugh and to isolate different sources of variability in the amount of laughter per conversation. More than half of the variability in the amount a person laughs is attributable to individual differences. This tendency to laugh negatively predicts conversation enjoyment. A smaller amount of variability in the amount people laugh is due to qualities of their conversation partners. Partners who tend to elicit others’ laughter are perceived as more relatable. We examined the personality correlates of laughter and found that less intellectual and less empathically-concerned participants (i.e., nonserious participants) produced and elicited more laughter. In summary, how much a person laughs is not a straightforward function of enjoyment. Instead, it is a behavioral trait associated with being perceived as relatable, supporting laughters’ proposed function of conveying harmless, nonserious intentions.

Inheritance of Acquired Traits in Insects and Other Animals and the Epigenetic Mechanisms that Break the Weismann Barrier

The credibility of the Weismann barrier has come into question. Several studies in various animal systems, from mice to worms, have shown that novel environmental stimuli can generate an altered developmental or behavioral trait that can be transmitted to offspring of the following generation. Recently, insects have become ideal models to study the inheritance of acquired traits. This is because insects can be reared in high numbers at low cost, they have short generation times and produce abundant offspring. Numerous studies have shown that an insect can modify its phenotype in response to a novel stimulus to aid its survival, and also that this modified phenotypic trait can be inherited by its offspring. Epigenetic mechanisms are likely at play but, most studies do not address the mechanisms that underlie the inheritance of acquired traits in insects. Here we first review general epigenetic mechanisms such as DNA methylation, histone acetylation and small noncoding RNAs that have been implicated in the transmission of acquired traits in animals, then we focus on the few insect studies in which these mechanisms have been investigated.

Collective action or individual choice: Spontaneity and individuality contribute to decision-making in Drosophila

Our own unique character traits make our behavior consistent and define our individuality. Yet, this consistency does not entail that we behave repetitively like machines. Like humans, animals also combine personality traits with spontaneity to produce adaptive behavior: consistent, but not fully predictable. Here, we study an iconically rigid behavioral trait, insect phototaxis, that nevertheless also contains both components of individuality and spontaneity. In a light/dark T-maze, approximately 70% of a group of Drosophila fruit flies choose the bright arm of the T-Maze, while the remaining 30% walk into the dark. Taking the photopositive and the photonegative subgroups and re-testing them reveals the spontaneous component: a similar 70–30 distribution emerges in each of the two subgroups. Increasing the number of choices to ten choices, reveals the individuality component: flies with an extremely negative series of first choices were more likely to show photonegative behavior in subsequent choices and vice versa. General behavioral traits, independent of light/dark preference, contributed to the development of this individuality. The interaction of individuality and spontaneity together explains why group averages, even for such seemingly stereotypical behaviors, are poor predictors of individual choices.

RNA-binding protein syncrip regulates starvation-induced hyperactivity in adult Drosophila

How to respond to starvation determines fitness. One prominent behavioral response is increased locomotor activities upon starvation, also known as Starvation-Induced Hyperactivity (SIH). SIH is paradoxical as it promotes food seeking but also increases energy expenditure. Despite its importance in fitness, the genetic contributions to SIH as a behavioral trait remains unexplored. Here, we examined SIH in the Drosophila melanogaster Genetic Reference Panel (DGRP) and performed genome-wide association studies. We identified 23 significant loci, corresponding to 14 genes, significantly associated with SIH in adult Drosophila. Gene enrichment analyses indicated that genes encoding ion channels and mRNA binding proteins (RBPs) were most enriched in SIH. We are especially interested in RBPs because they provide a potential mechanism to quickly change protein expression in response to environmental challenges. Using RNA interference, we validated the role of syp in regulating SIH. syp encodes Syncrip (Syp), an RBP. While ubiquitous knockdown of syp led to semi-lethality in adult flies, adult flies with neuron-specific syp knockdown were viable and exhibited decreased SIH. Using the Temporal and Regional Gene Expression Targeting (TARGET) system, we further confirmed the role of Syp in adult neurons in regulating SIH. To determine how syp is regulated by starvation, we performed RNA-seq using the heads of flies maintained under either food or starvation conditions. RNA-seq analyses revealed that syp was alternatively spliced under starvation while its expression level was unchanged. We further generated an alternatively-spliced-exon-specific knockout (KO) line and found that KO flies showed reduced SIH. Together, this study demonstrates a significant genetic contribution to SIH as a behavioral trait, identifies syp as a SIH gene, and highlights the significance of RBPs and post-transcriptional processes in the brain in regulating behavioral responses to starvation.

Measurement Invariance and the Socioecological Complexity Hypothesis

Lukaszewski et al. (2017) advanced a socioecological theory to account for differences in the strengths of covariances among disparate personality measurements in different cultures. They tested their theory using personality data gathered from 55 countries, and argued the results of their analysis implicated socioecological complexity as a modifier of personality trait covariances, thus providing evidence against rival explanations for observed differences in personality trait covariances between countries (e.g., life-history theory). While the socioecological complexity hypothesis is novel and interesting, we suggest that the analytic approach and several of the decisions made by Lukaszewski et al. are conceptually and analytically flawed. Accordingly, their findings should be considered cautiously and not construed as evidence against alternative explanations for differences in personality or other behavioral trait covariances within or across countries. Ultimately, their analyses can not empirically adjudicate their hypothesis or provide any means to decide between it and competing ones.

Collective action or individual choice: Spontaneity and individuality contribute to decision-making in Drosophila

Our own unique character traits make our behavior consistent and define our individuality. Yet, this consistency does not entail that we behave repetitively like machines. Like humans, animals also combine personality traits with spontaneity to produce adaptive behavior: consistent, but not fully predictable. Here, we study an iconically rigid behavioral trait – insect phototaxis – that that nevertheless also contains both components of individuality and spontaneity. In a light/dark T-maze, approximately 70% of a group of Drosophila fruit flies choose the bright arm of the T-Maze, while the remaining 30% walk into the dark. Taking the photopositive and the photonegative subgroups and re-testing them reveals the spontaneous component: a similar 70-30 distribution emerges in each of the two subgroups. Increasing the number of choices to ten choices, reveals the individuality component: flies with extremely negative first choices were more likely to show photonegative behavior in subsequent choices and vice versa. General behavioral traits, independent of light/dark preference, contributed to the development of this individuality. The interaction of individuality and spontaneity together explains why group averages, even for such seemingly stereotypical behaviors, are poor predictors of individual choices.

Intraspecific Behavioral Variation Mediates Insect Prey Survival via Direct and Indirect Effects

Conspecific individuals often exhibit behavioral differences that influence susceptibility to predation. Yet, how such trait differences scale to affect prey population regulation and community structure remains unclear. We used an 8 day field mesocosm experiment to explore the effects of intraspecific prey behavioral trait variation on survival in an herbivorous insect community. We further manipulated spider predator composition to test for top-down context-dependence of behavioral effects. Insect prey behavioral trait variance influenced survival through both direct (i.e., variation among conspecifics) and indirect (i.e., variation among heterospecifics) mechanisms. The behavioral variance of two prey species, Philaenus and Orchelimum, directly reduced their survival, though for Philaenus, this direct negative effect only occurred in the presence of a single spider predator species. In contrast, the survival of Scudderia was enhanced by the behavioral trait variance of the surrounding insect community, an indirect positive effect. Taken together, these results emphasize the importance of accounting for intraspecific variation in community ecology, demonstrating novel pathways by which individual-level behavioral differences scale to alter population and community level patterns.

Clonemate cotransmission supports a role for kin selection in a puppeteer parasite

Host manipulation by parasites is a fascinating evolutionary outcome, but adaptive scenarios that often accompany even iconic examples in this popular field of study are speculative. Kin selection has been invoked as a means of explaining the evolution of an altruistic-based, host-manipulating behavior caused by larvae of the lancet flukeDicrocoelium dendriticumin ants. Specifically, cotransmission of larval clonemates from a snail first host to an ant second host is presumed to lead to a puppeteer parasite in the ant’s brain that has clonemates in the ant abdomen. Clonal relatedness between the actor (brain fluke) and recipients (abdomen flukes) enables kin selection of the parasite’s host-manipulating trait, which facilitates transmission of the recipients to the final host. However, the hypothesis that asexual reproduction in the snail leads to a high abundance of clonemates in the same ant is untested. Clonal relationships between the manipulator in the brain and the nonmanipulators in the abdomen are also untested. We provide empirical data on the lancet fluke’s clonal diversity within its ant host. In stark contrast to other trematodes, which do not exhibit the same host-manipulating behavioral trait, the lancet fluke has a high abundance of clonemates. Moreover, our data support existing theory that indicates that the altruistic behavior can evolve even in the presence of multiple clones within the same ant host. Importantly, our analyses conclusively show clonemate cotransmission into ants, and, as such, we find support for kin selection to drive the evolution and maintenance of this iconic host manipulation.