Humans are classified as primates by Linnaeus (1735) and Darwin (1871).
Modern studies utilize DNA, morphology, behavior, and fossils for insights.
Shared characteristics of primates:
Grasping hands and developed vision.
Long juvenile periods and relatively large brains.
Comparable physiological and cognitive structures.
Reasoning by homology: focuses on similarities in anatomy and behavior due to common ancestry.
Primates exhibit diversity in:
Body size
Habitat and diet
Social organization
Activity patterns
Evolution influences behavior through reasoning by analogy, addressing adaptations and solutions to evolutionary challenges.
Common characteristics shared by all primates include:
Grasping hands and feet.
Nails instead of claws.
Hind-limb driven locomotion.
Reduced olfaction and enhanced vision.
Forward-facing eyes encased in bone.
Additional characteristics include:
Relatively large brains.
Long gestation periods.
Small litters (commonly one or two).
Extended juvenile periods.
Long lifespans.
Increased dependence on learning and behavioral flexibility.
Primate dental formula comprises:
Incisors (I), Canines (C), Premolars (P), Molars (M).
Upper dental formula: 2:1:2:3
Lower dental formula: 2:1:2:3
This uniformity across all primates indicates evolutionary traits.
Geographic distribution of primates:
Primarily tropical and forest-dwelling, arboreal animals.
Modern ranges include:
Americas, Africa, Asia.
Historically included regions such as North America and Europe.
Homo sapiens are unique in their range, having reached Australia, Greenland, and Antarctica.
Not all primates are equally related; the order diverges into two main suborders:
Strepsirrhini (strepsirrhines)
Haplorrhini (haplorrhines)
Characteristics:
'Twisted nose'—wet nose with rhinarium.
Presence of a tooth comb.
Tapetum lucidum present for night vision.
Dental formula: 2:1:3:3.
Divided into two infraorders:
Lemuriformes (lemurs)
Lorisiformes (lorises and galagos)
Characteristics:
'Simple nose'—dry nose without rhinarium.
Inability to produce Vitamin C.
Complete orbital plate with no tapetum but possess a fovea.
Divided into two infraorders:
Tarsiiformes (tarsiers)
Simiiformes (new and old world monkeys and apes)
Primarily located in Asia.
Characteristics:
Small, nocturnal insectivores.
Specialized for vertical clinging and leaping.
Lack tooth comb and tapetum.
Split into two parvorders:
Platyrrhines (New World monkeys)
Catarrhines (Old World monkeys and apes)
Characteristics include:
Flat noses with outward-facing nostrils.
Many species have prehensile tails.
Found in tropical forests of South and Central America.
Most Share a 2-1-3-3 dental formula.
Five families within Platyrrhini:
Callitrichidae (marmosets and tamarins)
Pair-bonders and cooperative breeders.
Atelidae (howler, woolly, and spider monkeys)
Suspensory climbers with prehensile tails.
Cebidae (capuchin and squirrel monkeys)
Highly social and omnivorous.
Aotidae (night and owl monkeys)
Only nocturnal anthropoid.
Pithecidae (titi, saki monkeys, and uakaris)
Diurnal, arboreal, and polygamous.
Characteristics:
Downward-facing nostrils.
Found in Africa and Eurasia.
Larger body sizes and diverse habitats compared to Platyrrhines.
Distinguishing dental formula: 2-1-2-3.
Two superfamilies:
Cercopithecoidea (Old World monkeys)
Hominoidea (apes)
Family: Cercopithecidae
Two subfamilies: Colobines and Cercopithecines.
Approximately 150 species, located in Africa and Asia.
Noteworthy traits include tails and ischial callosities.
Also known as Hominoids (apes).
Characteristics:
Generally larger brains, taillessness, and suspensory, orthograde climbing abilities.
Dental structure: unspecialized Y-5 molars.
Two families:
Hylobatidae (lesser apes)
Hominidae (great apes)
Features:
Includes gibbons (Hylobates) and siamangs (Symphalangus).
Habitat: Southeast Asia.
Characteristics include long arms for brachiation, pair bonding, and male parental care in siamangs.
Three Genera:
Gorilla (gorillas)
Homo (humans)
Pan (chimpanzees and bonobos)
Two subfamilies:
Ponginae: Contains the genus Pongo (orangutans).
Limited to Borneo and Sumatra.
Characteristics:
Three species, largest arboreal animal, primarily frugivorous, and relatively solitary.
Notable for intense male-male competition for mating.
Two species: Western (Gorilla gorilla) and Eastern (Gorilla berengei).
Characteristics:
Largest ape, lives in one-male/multifemale groups, diet includes mixed vegetation with fruits when available.
Divided into two species:
Pan paniscus (Bonobo)
Known for strong female social bonding, Congo region.
Pan troglodytes (Common chimpanzee)
Equatorial Africa, strong male social bonding, different conflict resolution methods between species.
Single living species: Homo sapiens
Characteristics:
Global distribution, diverse social and mating structures, primarily omnivorous diet, complex verbal communication, bipedalism, and advanced tool use.
Examines how primates interact with their environments.
Nutritional needs are essential for survival, influenced by several factors:
Basal metabolic rate.
Active metabolism.
Growth rate.
Reproductive effort.
Nutritional Needs:
Carbohydrates, amino acids (proteins), fats and oils, vitamins, minerals, and water.
Toxin Avoidance:
Awareness of bitter-tasting insects and leaves.
Diverse sources include:
Insects, animal prey, leaves, fruit, gum, seeds, and fats.
Examines strategies for nutrient acquisition.
Characteristics:
Small body size, sharp cusps on teeth, high crest on molars, and simple digestive systems.
Characteristics:
Larger body size, small incisors, sharp shearing crests on molars, and complex digestive systems.
Characteristics:
Medium body size, large broad incisors, low-cusped molars, and relatively large digestive systems.
Characteristics:
Relatively small size, long robust incisors, potential presence of claws (in callitrichids), and unspecialized digestive systems.
Home Range: Geographical area utilized by primates for activities, not defended.
Connects movements with resource distribution necessary for survival.
Territory: Actively defended area for breeding young, marked with displays, calls, and scents.
Typically smaller than home ranges, with territoriality varying among species.
Influenced by mates and resource availability.
Balances costs (risks in defense) and benefits (control of limited resources).
Primates face predation pressures, adapting through:
Arboreal evolution or increased body/group size.
Outcomes vary by geographic location and predator presence.
Strategies include:
Fleeing, vocalization with specific calls, forming associations, increased group size for detection and deterrence, mobbing behavior, and dilution of risk.
Benefits:
Predator avoidance and resource defense.
Costs:
Competition for food/mates and disease transmission.
Results in dominance hierarchies and resource access disparities.
Variations in social structure among primate species.
Endangerment is due to:
Habitat loss, poaching, subsistence hunting, bushmeat trade, pet trade, and disease.