evo. lecture 3 Flashcards
Primate Characteristics
- primate order with the class Mammalia.
- mammals have: hair or fur, four-chambered heart, spinal chord, and a neocortex region in the brain that controls sensory perception, spacial reasoning, and conscious thought.
- homeothermic: the ability to use energy from food to produce heat and self-regulate internal body temperature.
- non-mammals use ectothermy: the ability to regulate body temperature by environmental exposure.
- mammals have sweat glands: sweat-producing and ear-wax producing glands.
- these evolved into mammary glands.
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primates have:
- grasping hands and feet
- clavicle (collarbone), which allows shoulder motion and is important for life in arboreal environments
- radius and ulna, the two separate bones in the forearms which enable precise movements of the forearm and hand
- forward-facing eyes
- stereoscopic vision: using both eyes to see, which produces overlapping vision, and depth perception: visual ability to judge distance
- long lifespan, i.e. long periods of infancy, childhood, and adulthood.
Primate Activity Patterns
- nocturnal: active at night and sleeping during the day.
- diurnal: active during the day and sleeping at night.
- crepuscular: active primarily during dawn and dusk.
- cathemeral: active any time of the day.
Primate Taxonomy
- Strepsirhines: Lemurs, Lorises, and Galagos
- Haplorhines: Tarsiiformes, Platyrrhines, and Catarrhines
Strepsirhine Characteristics
- primitive features: traits that are old on a phylogenetic scale of development.
- dental tooth comb.
- moist rhinarium: i.e. wet nose, enhances sense of smell.
- unfused mandibular (jaw bone) and frontal symphases (forehead).
- Tapetum lucidum: an extra layer of tissue in the eye that reflects light, thereby enhancing night vision.
- postorbitol bar: a ring of bone around the eye socket; non-primate mammals have neither a postorbital bar nor postorbital closure.
- two super families: Lemuroidea and Lorisoidea.
Lemuroidea (Lermus) | Strepsirhine
- ound on the islands of Madagascar and Comoro (in the Indian Ocean off the southeast coast of Asia).
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arboreal quadrupeds: using all four limbs to travel.
- a few are terrestrial.
- vertical clinging and leaping: clinging to vertical or inclined substrate in upright position and then leaping towards and grasping another vertical or inclined substrate.
- small-bodied lemurs (under 1kg) are nocturnal and have larger eyeballs relative to their body size.
- females are often dominant to males in ecological and social settings.
Haplorhine Characteristics
- derived features: a character state that differs from that of a common ancestor.
- dry nose, meaning a greater reliance on vision.
- retinal fovea: a characteristic of the eye that reduces night vision but improves visual accuracy.
- postorbital closure.
- fused mandibular and frontal symphases (cf. Tarsiers).
- three infraorders: Tarsiiformes, Platyrrhini, and Catarrhini.
Tarsiiformes | Haplorhine
- Tarsiiforme: infraorder comprising tarsiers.
- only one genus, Tarsius.
- tropical forests on the islands of the Phillipenes, Sulawesi, Borneo, and Sumatra in Southeast Asia.
- 80-130kg (small), with long legs relative to body size.
- fused fibula and tibia (lower leg bones) to help stability during leaping.
Human Beings: Homo sapiens
- habitual, upright, bipedal posture and locomotion.
- forelimb for manipulation, not locomotion.
- increased brain volume.
- reduction of teeth, jaws, and chewing muscles.
- but are we really so different from nonhuman primates?
Body Size
- scaling: Area (L x W) and volume (L x W x D) change at different rates.
- animal doubles in size will be eight times heavier.
- small animals have greater heat (energy) loss than larger animals.
- large primates can subsist on large amounts of low-energy foods
- small primates must eat small amounts of high-energy foods.
Habitat
a place that provides adequate nutrients, water, and living space.
Primate Evolutionary Ecology
- bottom-up processes: interactions between organisms involving physical or chemical factors such as temperature of nutrient availability.
- top-down processes: influence of consumers, such as predators, on prey.
- seed dispersal: specific fruit characteristics to entice animals to eat the juicy parts and then disperse the seeds in fees dropped away from the parent plant.
- pollinator: agent that transports small amounts of nectar and pollen, e.g. on fur or by mouth, between flowers.
- predation: predators can have a top-down influence on primates; if a group of predators move into primate territory, the primates must deal with acquiring food resources from plants (bottom-up processes) and avoiding predation (top-down process).
- plant defensive adaptions: plants have a variety of physical (e.g. stinging hairs on stems and leaves) and chemical (e.g. injecting poisons) defences to protect leaves, flowers, and other mammals; primates have adaptations to deal with plant defences.
Daily Path Length | Ranging Patterns
refers to the one-dimensional distance travelled by a primate during its daily active period.
Primate Sociality
- deception
- female mate choice
- homosexuality
- kin recognition
- warfare
- friendship
- primates demonstrate complex social lives.
Primate Social Grooming
- more about establishing and maintaining social bonds than hygiene.
- primates groom each other to establish and maintain alliances, reconcile conflict, and to exchange for other resources such as food and sex.
Primate Dominance Hierarchies
dominance hierarchy: a social order sustained by aggression, affiliation, or other behaviour patterns.
Primate Social Organization
- residence group composition: primate social groupings based on the number of individuals in differing age-sex classes.
- mating systems: who mates with whom.
- foraging coherence: who eats with whom, and where and when.
- female philopatry: male leaves at sexual maturity.
- male philopatry: females leave at sexual maturity.
Why Do Primates Live in Groups?
- advantages:
- improved predator protection
- improved access to food
- increased access to potential mates
- increased resource defence
- disadvantages
- increased predator encounters
- increased travel/foraging costs
- more mouths to feed
- disease transmission
Primate Conservation
- habitat disturbance
- logging
- agriculture
- forest fragmentation
- hunting pressures
- subsistence vs. economic
Primate Conservation: Biology and Anthropology
- if your most cherished and loved person was dying only of hunger, wouldn’t you do just about anything to save him/her?
- must respect culture, find practical solutions involving local people.
Primate Diets
- food consists of fruits, flowers, insects, and leaves.
- only a few eat leaves and require a special adaptation for it.
- complex stomach: adaptation to allow bacterial fermentation of leaves.
Lorisidae (Lorises and Galagos) | Strepsirhine
- forested regions of sub-saharan Africa and Southeast Asia.
- Lorises are arboreal quadrupeds.
- Galagos are arboreal and nocturnal.
Platyrrhines | Haplorhine
- Central and South America
- mostly arboreal
- prehensile tail: a tail that can support the entire body weight of the animal.
- three primate families: Cebidae, Atelidae, and Callitrichidae.
Catarrhines | Haplorhine
- Old World Monkeys and Apes
- from 1-175kg.
- three families: Cercopithecidae, Hylobatidae, and Hominidae.
- Africa, Asia, and Southeast Asia
- sexually dimorphic: males and females of the same species having different features.
- variety of diets, social organizations, and adaptations.
Tropical Rainforests | Habitat
forest habitats typically near the equator that are characterized by high annual temperatures and rainfall.
Primary Forest | Habitat
intact natural forest characterized by an abundance of mature trees that have not been disturbed or modified by human activities or natural disturbances.
Secondary Forest | Habitat
what re-grows after a disturbance, and there tends to contain denser, shorter vegetation than that seen in primary forests.
Ecological Niche | Habitat
sum of all the interactions between an organism and its ecosystem.
Forest Microhabitats
- forest microhabitats: emergent layer, canopy, and understory.
- emergent layer: topmost level of the tree, which is usually exposed to sunlight.
- canopy: system of horizontal branches and foliage formed by the tree crowns (i.e. the leafy parts)
- understory: area between the ground and lowest horizontal branches.
Day Range | Ranging Patterns
two-dimensional area used by a primate throughout a 24-hour period.
Home Range | Ranging Patterns
two-dimensional area used by a primate throughout months or years.
Core Area | Ranging Patterns
most frequently used part of the home range.
Territory | Ranging Patterns
an area actively defended by an individual or group.