B1 Non-lecture content Flashcards
Research in primate cranial diversity
- Fleagle et al, 2010:
- 3D geometric morphometric analysis of primate cranial morphology- major patterns of cranial shape change during primate evolution and quantitative assessments of cranial diversity among different clades
- first axis- differences in cranial flexion, orbit size and orientation, and relative neurocranial volume- separates strepsirrhines from anthropoids
- second axis- differences in relative cranial height and snout length- differences among anthropoids
- extremes in cranial shape- Eulemur, Man- drillus, Pongo, and Homo
- Anthropoids, catarrhines, and haplorhines show a higher variance than prosimians or strepsirrhines
- greatest variance in Anthropoids, catarrhines, and haplorhines show a higher variance than prosimians or strepsirrhines- driven by unique cranium of homo sapiens
Behavioural and morphological adaptations for foraging in primates
- Janson & Boinski (1992)- generalist primates- cebines- body size is extremely important in explaining the observed variation in diet (faunivory- high protein)- emphasis on faunivory is facilitated more by behavioral than by morphological specialization (e.g. small hierarchal group) - whatever morphological specializations are present are probably favoured by diet at the most food-depauperate time of year, although morphology may well reveal what a primate may potentially eat, to map this potential onto actual diet requires a detailed knowledge of its natural ecosystem
Outline an example of association under predation pressure in primates
- Noë & Bshary (2021)- mixed-species groups of red colobus and Diana monkeys in Tai national park- Red colobus, but not diana monkeys, are frequently killed by cooperatively hunting chimpanzees- association rates peaked during the chimpanzees’ hunting season, as a result of changes in the behaviour of the red colobus, playbacks of recordings of chimpanzee sounds induced the formation of new associations and extended the duration of existing associations (no effect with leopard recordings)
Outline an example of niche overlap and associations in primates
- Motani (1991)- Sympatric Cercopithecids in the Campo Animal Reserve- community structure and polyspecific associations found in five sympatric resident primates- five species shared similar food niches, but foraging biomass varied significantly, used similar foraging areas/strata- cant be explained by conventional equilibrium-competition models- primates form polyspecific foraging groups in order to optimize their foraging biomass- can also explain grouping behaviour in large primates e.g. fission-fusion
outline an example of interaction of male and female reproductive strategies in primates
Soltis et al (2001):
- wild Japanese macques- reproductive strategies of both sexes operate simultaneously
- socially dominant males monopolized most female matings
- six offspring sired by troop males were more likely sired by higher-ranking males than lower-ranking males
- Lower-ranking troop males avoided direct competition with higher-ranking males by engaging in sneak copulations with females outside of the presence of other males
- females expressed mate choice behaviour towards multiple males of various dominance ranks- female strategy of attempting to mate with multiple males conflicted with the mate-guarding strategy of high-ranking males
- number of females mating simultaneously influences the outcome of reproductive conflicts between the sexes
Study on female reproductive strategies in orangoutangs
Knott et al (2010):
- Intersexual conflicts over mating can engender antagonistic coevolution of strategies, such as coercion by males and selective resistance by females
- high levels of forced copulation- typically viewed as an alternative mating tactic used by the competitively disadvantaged unflanged male morph, with little understanding of how female strategies may have shaped and responded to this behaviour
- However, male morph is not by itself a good predictor of mating dynamics- female conception risk mediated the occurrence and quality of male–female interactions
- When conception risk was low, willingness to associate and mate with non-prime males increased
- suggests together with concealed ovulation, facultative association is a mechanism of female choice in a species in which females can rarely avoid coercive mating attempt- may provide additional mechanism for mate selection
- still role of coercive as rime males were frequently aggressive to females and females used mating strategies consistent with infanticide avoidance
Outline an example of the role of social strategy in primate niche construction
MacKinnon & Fuentes:
- role of social cooperation and altruism
- elements of primate (at least anthropoid) sociality that act as baseline for subsequent expansion and elaboration during human evolution
- strong. social attachments may be necessary for survival- manipulation of those bonds are characteristic of all gregarious primate societies- complex sociality is a core primate adaptation (Silk, 2007)
- reciprocity- symmetry based, attitu- dinal based, and calculated (deWaal and Brosnan, 2006)
- Social and Ecological Niche Construction and Hyper-Sociality as Primate Heritage- 3 mind types- social, primate, and cultural- physiological and social correlates of social mandate are an extended period of infant development and brain maturation, which allows for the acquisition of species-appropriate skill sets and knowledge
- basal complex sociality of mammals is enhanced in primates, and primates then use their social networks/contexts as a tool to meet and modify the demands of the environment
Increased cognitive complexity in the hominoids facilitates a faster or more intensive utilization of the social bonds and relationships as tools to meet ecological challenges
- extensive cooperation and intensive reciprocity means altruism experienced without negative fitness costs- but no individuals uniformly altruistic
- altruistic action emerges as a by-product of the physiological and behavioral adapta- tions required to effectively negotiate high level and complex social networks where coalitions, multi-party social negotiations, and reciprocity are the primary avenues for social and reproductive success
Altruism explanation in primates
MacKinnon & Fuentes:
- basal complex sociality of mammals is enhanced in primates, and primates then use their social networks/contexts as a tool to meet and modify the demands of the environment
Increased cognitive complexity in the hominoids facilitates a faster or more intensive utilization of the social bonds and relationships as tools to meet ecological challenges
- extensive cooperation and intensive reciprocity means altruism experienced without negative fitness costs- but no individuals uniformly altruistic
- altruistic action emerges as a by-product of the physiological and behavioral adapta- tions required to effectively negotiate high level and complex social networks where coalitions, multi-party social negotiations, and reciprocity are the primary avenues for social and reproductive success
Outline findings varying cognition across primates
- Seed & Tomasello (2009)- difference between humans and other primates in more complex cognitive skills e.g. reasoning about relations, causality, time, and other minds- and humans have species unique set of adaptations for cultural intelligence; however things in common- physical and social worlds of humans and their living primate relatives pose many of the same evolutionary challenges- the most basic cogni- tive skills and mental representations that humans use to navigate those worlds are already possessed by other primate
Outline example of cultural behaviour across species
Whiten (2021)
- examples across species- primate tool use, social learning uin dolphins, birdsong traditions, social learning in invertebrates (e.g. bee foraging)
- cultural development drives genetic evolution
Outline the link between efficiency and cumulative culture
Gruber et al, 2021:
- learnable behaviours are requirement for evolution of complexity
- efficiency facilitates cumulative culture development- explains how similar cultural evolution can be between taxonomically diverse species
- Multicomponent behaviours must be composed of easy-to-learn components if they have any hope of passing through the bottleneck of social transmission
- When the bottleneck is more severe, more learnable traits have a better chance of persisting in wild populations- universal pressure for learnability
Outline how group size mediates costs and benefits of group living in primates
Markham & Desquiere (2017)- ecological constraint model:
- costs and benefits of group living vary in female primates as a function of group size
- As group size increases, food patches are more rapidly depleted (scramble competition)
- competitive regimes- under intense between-group competition when resources are discrete and defensible, the model predicts that energy gain of females in smaller groups is less than that of females in larger groups- if combined with within-group competition, energy gain declines linearly with female rank in each group
- should be an equilibrium point where a low-ranking female in a large (socially dominant) group has the equivalent energy gain to a high-ranking female in a small (socially subordinate) group
- several advantages to living in smaller groups (e.g. decreased within-group competition for food resources) and several advantages to living in larger groups (e.g. increased probability of winning between-group contests)- measured physiologically (glucocorticoids, c-peptides and thyroid hormones)
- U-shaped relationship between group size and average daily travel distance, home-range size, evenness of space use, and glucocorticoid levels
benefits of group living in primates
- e.g. of large groups- red colobus (Snaith et al, 2008)
- foraging time is expected to decrease as group size increases if larger groups outcompete smaller groups for food resources (Schoener, 1971)
- large groups occupy higher quality portions of landscape (e.g. in Gibbons- Marshall, 2010)
- grooming- hygienic function (Henzi & Barrett 1999)
- decrease predation rosh (van Schaik, 1983)- lookouts, geometry of the selfish herd- less chance of predated if in larger group (Hamilton, 1971)
- easier mating (Swedell, 2012)
- large group outcompete- e.g. at waterholes and sleeping sites (Wrangham, 1980)
Costs of primate group living
- Chapman, 2015- human disturbance to habitats e.g. baboon will decrease resource availability, which should theoretically favour smaller groups- larger groups deplete patches faster and if habitat disturbance decreases patch availability, it increases the distance between patches and groups must travel further
- Markham & Desquiere, 2017- Increased within-group competition for food- (Janson, 1985- capunchins)
- competition- mediated by dominance hierarchies- can lead to injury nd death (Mason & Mendoza, 1993)
- infanticide- increases stress hormone levels (Engh et al, 2006)
- close social contact also increases the potential transmission of pathogens (Swedell, 2012)
application of ancient DNA
- de Sousa (2012) - fossil brain genetics- evidence which can be used in conjunction with archeological and paleontological evidence to reconstruct the structure and function of fossil hominin brains- suggests human-specific cognition and brain morphology may be the product of contributions from multiple hominin lineages- H. neanderthalensis may have contributed 1–4% of the genomes of living Eurasian H. sapiens (Green et al., 2010)
- Green et al., 2010- Differences between the genomes of H. neanderthalensis and H. sapiens have been identified and could potentially be linked to species-specific cognition- several genes associated with human neurological disorders- e.g. DYKR1A (link with Down syndrome)
- Blois (2016)- opportunity to study the impact of climate change on the structure and genetic diversity within past populations and species- Genetic change is a result of population-level processes such as recombination, mutation, selection, random genetic drift, and gene flow- take place over thousands of years
