Biological Anthropology and Primate Behavior

Naked Mole Rats
  • Eusocial Mammals
    • Live in underground colonies
    • One breeding female suppresses fertility of male and female workers through pheromones.
    • A few males act as guards against threats to the colony.
    • High inbreeding due to isolation, similar to termite colonies.
    • Workers:
    • Dig elaborate tunnel systems.
    • Locate roots and tubers.
    • Transport food back to the breeding chamber.
Bird & Mammal Cooperative Care
  • Rarity of Cooperative Rearing:
    • Generally occurs in environments with scarce resources and nest sites.
    • Additional demands of defending a nest site necessitate involvement of multiple males and females.
    • Advantages for fledglings:
    • Stay with parents to feed the next brood.
    • Aid in nest defense.
    • Develop necessary size, skills, and strategies for establishing a new nest.
Helper-at-the-Nest Strategy
  • Example: Desert Brown Babblers
    • Nest sites are rare, so cooperative efforts (e.g., "clan warfare") are essential.
    • Larger clans can defend better nesting sites.
    • Young helpers postpone reproduction, passing on genes by proxy via helping their parents.
Social Carnivore Cooperation
  • Mixture of strategies in cooperative carnivores
  • Helper-at-the-nest strategy:
    • Aids parent's reproduction (kin selection).
    • Cooperation provides access to different prey and den resources.
    • Group members await opportunities to replace dominant individuals or start new packs.
  • Example: African Wild Dogs
    • Cooperative hunting for large species.
    • Dominant pair reproduces while older cohorts hunt and provide food for pups via regurgitation.
Female Lions - Social Carnivory
  • Cooperative care allows multiple females to hunt while others nurse and protect cubs.
  • Cooperative hunting is crucial for taking down large game.
Male Lions - Competition for Prides
  • Males compete to defend female prides.
  • Cooperation necessary in pride takeovers, which can be deadly.
  • Short reign for male pride leaders, females take time to become pregnant, and cubs take years to mature.
Lion Infanticide
  • High male competition for pride takeover leads to systematic attacks on infants of a deposed dominant male.
  • Effects:
    • Ensures females return to estrus faster.
    • Females may feign receptivity to protect young.
Reciprocal Altruism in Vampire Bats
  • Bats roost in stable groups but face unreliable food supply due to high metabolism.
  • Supplementary feeding from roost-mates is often necessary.
Conditions Favoring Reciprocal Altruism
  • Low cost of giving aid.
  • High benefit of receiving aid.
  • Long-term associations facilitate reciprocity.
  • Mechanisms for identifying and punishing non-reciprocators.
Reciprocity in Human Societies
  • All human societies have rules maintaining stable reciprocity among individuals and kin groups.
  • Important aspects:
    • Marriage rules
    • Defense practices
    • Exchange relationships
  • Language aids in establishing and maintaining reciprocal agreements.
Typical Primate Features
  • Morphological Characteristics:
    • Prehensile hands and feet, opposable thumb and toe.
    • Flat nails instead of claws, with some exceptions.
    • Forward-facing eyes and orbital enclosure.
    • Color vision present in monkeys and apes.
    • Reduced reliance on smell.
    • Mostly uniparous; young carried by parents.
    • Larger brain size relative to body.
    • Adaptations to tropical and subtropical environments.
Phylogeny of Primate Taxa
  • Evolutionary history over 65 million years:
    • Tree shrews and colugos as closest outgroups.
    • Major divisions:
    • Old World Monkeys (OWM)
    • New World Monkeys (NWM)
    • Apes (including humans)
  • Other taxa: Tarsiers, Lorises, Lemurs.
Colugo and Tupaia
  • Colugo (Flying Lemur):
    • Arboreal glider, frugivorous-insectivorous.
    • Uniparous with young carried.
  • Tupaia (Tree Shrew):
    • Arboreal, insectivorous, has grasping hands.
Phylogenetic Tree Overview
  • Summary of major primate divisions including Strepsirrhini and Haplorhini.
  • Visual representation of evolutionary relationships among primate taxa.