Overview of Lecture: Behavioral Ecology Read: Text ch 51 Bullet Points: •! behavior •! behaviorism, psychology •! ethology, behavioral ecology •! genes - "nature" •! environment - "nurtue" •! GxE interactions •! cooperation •! mutualism; kinship •! reciprocity; manipulation •! social games •! social intelligenceIf we consider the development {ontogeny} of any behavioral trait, we find a series of environmental {“nurture”} and genetic {“nature”} influences that can ‘interact’ as well as ‘add up’ to influence the phenotype-trait. Tinbergen’s four “whys”In a prospective-longitudinal study of a representative birth cohort, we tested why stressful experiences lead to depression in some people but not in others. A functional polymorphism in the promoter region of the serotonin transporter (5-HTT) gene was found to moderate the influence of stressful life events on depression. s/s s/ l l/ l Individuals with one or two copies of the short allele of the 5-HTT promoter polymorphism exhibited more depressive symptoms, diagnosable depression, and suicidality in relation to stressful life events than individuals homozygous for the long allele. no effect of env on I/I genotype no eff of genotype in No-mal. env {depression “emerges” from an interaction} recall from 1st lectureThree fundamental ideas in behaviorism, that justified the arbitrary use of rats & pigeons as models of humans were that 1. humans (& other animals) are born with minds that are blank slates … 2. we are conditioned by experiences written on our blank slates, and 3. the conditioning process is the same ‘general process’ across all species.Imprinting: learning that is limited to a ‘sensitive period’ in an animal’s life; generally irreversible.A simple path model of the evolution of behavior: (Boyd & Richardson1985) zygotes Genes ‘nature’ Social learning ‘nurture’ vertical transmission Ecol. & Social Env. horizontal trans It is very difficult to tease apart the effects of genes, esp w/o carefully controlled experiments. Parents selection Other complications include ‘maternal effects’ ex: womb environment Even w/ experiments, difficult if genes & env ‘interact’ - diff genotypes react to diff env’s differently: (effects not additive) Parents children and gene-environment correlations (parents influence social env) If we consider the development {ontogeny} of any behavioral trait, we find a series of environmental {“nurture”} and genetic {“nature”} influences.Honey, I'm home. ...the amount of junk DNA affects how male voles treat their mates. genotype your boyfriend ?Fig 1 Sex differences in wild chimpanzees learning termite-fishing. a % time at the termite mound spent termite-fishing by young chimps. b Daughters' techniques (top) correlate strongly with their mothers'. {lines have + slope ~1} Females spent more time than males watching their mothers fish for termites sons' techniques (bottom) do not correlate with their mothers' {lines have flat slope ~0} Males spent more time playing at the termite mound A similar disparity in the ability {?} of young males & females to learn skills has been demonstrated in human children 8 males 6 females short tool medium tool long tool 00% Sex differences in learning in chimpanzees. Lonsdorf et al. 2004 Nature 428, 715-716. Wild chimpanzees … fish for termites with flexible tools they make out of vegetation, … We find distinct sex-based differences, akin to those found in human children, in the way in which young chimpanzees develop their termite-fishing skills. boys learning ?However, evidence from patients with endocrine disorders suggests that biological factors during early development (e.g., levels of androgens) are influential. In this study, we found that vervet monkeys (Cercopithecus aethiops sabaeus) show sex differences in toy preferences similar to those documented in children. For each trial, six toys were placed in the group cage, one at a time, in a random order … for 5 min. These toys were categorized as "masculine" toys, "feminine" toys, or "neutral" toys on the basis of evidence that boys are more interested than girls in balls and cars (the "masculine" toy set), girls are more interested than boys in dolls and pots (the "feminine" toy set), and boys and girls are approximately equally interested in books and stuffed animals (the "neutral" toy set) Videotapes were coded for the duration of contact and approach to each of the toys. Percent contact scores equaled contact with each individual toy divided by total contact with any of the six toys!100.The percent of contact time with toys typically preferred by boys (a car and a ball) was greater in male vervets (n=33) than in female vervets (n=30) (P<.05), the percent of contact time with toys typically preferred by girls (a doll and a pot) was greater in female vervets than in male vervets (P<.01). … contact time with toys preferred equally by boys and girls (a picture book and a stuffed dog) was comparable in male and female vervets. The results suggest that sexually differentiated object preferences arose early in human evolution, prior to the emergence of a distinct hominid lineage. {gene-environment correlation: genes choose env?} more recent studies confirm that ‘boy monkeys’ like to push wheeled toys, and ‘girl monkeys’ like to hold plush toysFood sharing in a captive colony of chimps was studied … The success rate of each adult, A, to obtain food from another adult, B, was compared w/ grooming interactions between A & B in the 2 hours prior to each food trial. How Animals Do Business Reciprocity and interchange in the social relationships of wild male chimpanzees. Watts DP. BEHAVIOUR 139: 343-370 Part 2-3 FEB-MAR 2002 Grooming and agonistic support: a meta-analysis of primate reciprocal altruism Schino G Behavioral Ecology 18: 115-120 JAN-FEB 2007LONELYplayer 2 c d 2 3 c 2 0 0 1 d 3 1 Two players w/ two tactics: cooperate, defect player 1Given the choice, people prefer institutional arrangements in which those who over consume common-property resources are punished compared to those