Bio Anth Exam 2 Flashcard text
What trait distinguishes primates from other mammals in terms of limbs?
Grasping hands and feet with opposable thumbs/toes.
Which primate feature enhances depth perception?
Forward-facing eyes (stereoscopic vision).
What is the significance of a reduced olfactory bulb in primates?
Reflects reliance on vision over smell.
Name two types of primate locomotion.
Arboreal quadrupedalism, brachiation, knuckle-walking, or bipedalism.
What distinguishes strepsirrhines from haplorhines?
Strepsirrhines: moist rhinarium, smaller brains. Haplorhines: dry nose, larger brains.
Why do primates have generalized dentition?
To process diverse diets (fruits, leaves, insects).
What is the role of the postorbital bar in primates?
Protects the eye socket during chewing/mechanical stress.
Which primate group lacks a toothcomb?
Haplorhines (tarsiers, monkeys, apes).
What is ‘fission-fusion’ social organization?
Groups split (fission) and merge (fusion) based on resource availability.
How do primates exhibit behavioral flexibility?
Through learned behaviors, tool use, and complex social interactions.
What is the dental formula of most New World monkeys?
2.1.3.3 (same as most primates).
Which primates have a tapetum lucidum?
Strepsirrhines (e.g., lemurs, lorises).
What is a ‘toothcomb’?
A specialized set of lower incisors and canines used for grooming in strepsirrhines.
Which primates exhibit vertical clinging and leaping?
Tarsiers and some lemurs.
What is the function of ischial callosities?
Thickened skin pads on the buttocks for sitting on rough surfaces (common in Old World monkeys).
What is a diurnal primate?
Active during the day.
Which primates are primarily nocturnal?
Tarsiers, lorises, and most lemurs.
What is alloparenting?
Infant care by individuals other than the biological mother.
What primate has the longest relative leg length?
Tarsiers (for leaping).
What is a prehensile tail?
A tail capable of grasping (e.g., in spider monkeys).
Which primates lack a prehensile tail?
Apes (e.g., chimpanzees, gorillas).
What is the primary diet of folivorous primates?
Leaves.
How do frugivorous primates aid seed dispersal?
By eating fruits and excreting seeds.
What primate has the largest body size?
Gorillas.
What is sexual dimorphism in primates?
Physical differences between males and females (e.g., size, coloration).
Which primates have the greatest sexual dimorphism?
Gorillas and mandrills.
What is a ‘dominance hierarchy’?
A ranking system determining access to resources within a group.
How do primates communicate dominance?
Through displays, vocalizations, or physical aggression.
What is the function of scent-marking in lemurs?
Territory defense and mating signals.
What is a ‘polygynous’ mating system?
One male mates with multiple females.
Which primates are strictly monogamous?
Gibbons and some titi monkeys.
What is neocortex expansion in primates linked to?
Complex social behavior and problem-solving.
What is the significance of trichromatic vision in some primates?
Allows detection of red/green colors (useful for fruit identification).
Which primates are dichromatic?
Most strepsirrhines and some New World monkeys.
What is ‘brachiation’?
Arm-swinging locomotion (e.g., gibbons).
What primate has the strongest bite force?
Gorillas (due to folivory).
What is the gestation period of a chimpanzee?
~8 months.
What primate has the longest lifespan in the wild?
Humans, followed by chimpanzees (~40-50 years).
What is ‘altricial’ development?
Offspring born helpless and requiring prolonged care.
What is ‘K-selected’ reproduction?
Few offspring with high parental investment (common in primates).
Which primate uses tools to fish for termites?
Chimpanzees.
What is ‘culture’ in primates?
Learned behaviors shared within a group (e.g., nut-cracking in chimpanzees).
Which primates exhibit cooperative hunting?
Chimpanzees and capuchin monkeys.
What is ‘philopatry’?
Remaining in one’s birth group (common in female chimpanzees).
What primate has a ‘sacculated stomach’?
Colobine monkeys (for fermenting leaves).
How do lorises avoid predators?
Slow, stealthy movement and toxic saliva.
What is ‘geophagy’?
Eating soil (for minerals/detoxification in some primates).
What primate has a ‘pseudo-opposable’ thumb?
Spider monkeys (reduced thumb for better brachiation).
What is ‘sympatric speciation’?
Evolution of new species in the same geographic area.
Which primates are endemic to Madagascar?
Lemurs.
What is the primary threat to primates today?
Habitat loss and hunting.
Which epoch marks the rise of early primates (euprimates)?
Eocene (~56-34 mya).
What key adaptation defined Adapis and Notharctus?
Grasping hands, forward-facing eyes (early euprimate traits).
Which fossil primate is a likely ancestor of modern haplorhines?
Eosimias (small, tarsier-like primate from Asia).
What distinguishes Aegyptopithecus?
Early catarrhine with Y-5 molar pattern (ancestral to apes/OW monkeys).
How did the Miocene climate shift affect apes?
Cooling/drying led to forest fragmentation, favoring monkeys over apes.
What is the significance of Sahelanthropus tchadensis?
Possibly the earliest hominin (6-7 mya, bipedal adaptations).
Which primate group is ancestral to all apes and humans?
Proconsulids (Miocene apes from Africa).
What evolutionary trend occurred in primate brain size?
Steady increase in encephalization over time.
Why is Darwinius masillae (‘Ida’) controversial?
Debated whether it’s a strepsirrhine or early haplorhine.
How did the asteroid impact (K-Pg boundary) affect primates?
Cleared niches for mammal radiation, including early primates.
What is the significance of Plesiadapis?
Early primate-like mammal from the Paleocene.
Which primate is considered the ‘first true primate’?
Teilhardina (Eocene euprimate).
What distinguishes Omomyoids from Adapoids?
Omomyoids: nocturnal, tarsier-like. Adapoids: diurnal, lemur-like.
What is the ‘Arboreal Hypothesis’ for primate origins?
Primate traits evolved for life in trees.
What is the ‘Visual Predation Hypothesis’?
Forward-facing eyes evolved to hunt insects in branches.
Which Miocene ape is linked to orangutan ancestry?
Sivapithecus.
What fossil group bridges the gap between apes and humans?
Australopithecines.
What is the significance of the Fayum Depression?
Rich fossil site for early anthropoids (e.g., Aegyptopithecus).
Which primate is ancestral to New World monkeys?
African anthropoids that rafted to South America.
What is the ‘Out of Africa’ hypothesis for primate evolution?
Apes and humans originated in Africa, then dispersed.
What distinguishes Dryopithecus?
Miocene ape with suspensory adaptations (ancestor of African apes).
How did the Oligocene cooling affect primates?
Favored monkeys over lemur-like adapoids.
What is the ‘Molecular Clock’ in primate evolution?
Estimates divergence times using DNA mutation rates.
When did hominins split from chimpanzees?
~6-7 mya.
What is the significance of Ardipithecus ramidus?
Early hominin with bipedalism and arboreal traits.
Which primate fossil shows evidence of tool use?
Australopithecus garhi (associated with cut-marked bones).
What is the ‘Savanna Hypothesis’ for human evolution?
Bipedalism evolved as forests shrank and savannas expanded.
What distinguishes Paranthropus from Australopithecus?
Paranthropus: robust skulls, specialized for chewing.
Which fossil is nicknamed ‘Lucy’?
Australopithecus afarensis.
What is the significance of the Laetoli footprints?
Evidence of bipedalism in Australopithecus afarensis.
How did Homo erectus differ from earlier hominins?
Larger brain, body proportions similar to modern humans.
What is the ‘Multiregional Hypothesis’ for human evolution?
Homo sapiens evolved in multiple regions from H. erectus.
What is the ‘Recent African Origin’ model?
Homo sapiens evolved in Africa and replaced other hominins.
What is the significance of Neanderthal DNA in modern humans?
Indicates interbreeding (~1-4% in non-Africans).
Which hominin first used fire?
Homo erectus.
What is the ‘Hobbit’ (Homo floresiensis)?
Small-bodied hominin from Flores, Indonesia.
What distinguishes Homo habilis?
First Homo species, associated with Oldowan tools.
What is encephalization quotient (EQ)?
Ratio of brain size to body size (higher in humans).
How did tool use influence hominin evolution?
Favored manual dexterity, planning, and social learning.
What is the ‘Grandmother Hypothesis’?
Post-reproductive females enhance group survival through childcare.
Why are lemurs only found in Madagascar?
Island isolation after rafting from Africa ~60 mya.
What limits primate distribution in Asia?
Himalayan mountains and seasonal monsoons.
Which continent has the highest primate diversity?
South America (NW monkeys, diverse habitats).
How did the Isthmus of Panama impact primates?
Allowed capuchin monkeys to migrate north during GABI.
Why are there no apes in the Americas?
Apes evolved in Africa/Asia after continents separated.
What primate thrives in Japan’s snowy habitats?
Japanese macaques (snow monkeys).
Which primate is adapted to Ethiopian high-altitude grasslands?
Gelada baboons (gramnivores with specialized dentition).
How did Pleistocene glaciations affect primate ranges?
Forced tropical species into refugia (e.g., Amazon, Congo Basin).
What primate is endemic to Borneo and Sumatra?
Orangutans (Pongo spp.).
Why are colobine monkeys absent in the Americas?
Evolved in Africa/Asia; NW monkeys lack sacculated stomachs.
What is Wallace’s Line?
Biogeographic boundary separating Asian and Australian fauna.
Why are tarsiers only found in Southeast Asia?
Evolved in isolation after continental drift.
What primate inhabits the Amazon Basin?
Spider monkeys, howler monkeys, and tamarins.
How do river barriers influence primate speciation?
Isolate populations (e.g., Amazon River separating squirrel monkey species).
What is an endemic species?
A species native to a single geographic region.
What is the ‘ecological model’ of sociality?
Group size/shape depends on predation risk and resource distribution.
Why do female primates often form kin-based alliances?
To enhance resource access and infant survival.
What is ‘infanticide’ as a reproductive strategy?
Males kill infants to hasten females’ return to fertility.
How do vervet monkeys demonstrate cultural behavior?
Learned alarm calls for specific predators.
What is the function of allogrooming?
Strengthens social bonds and reduces parasites.
Why do orangutans have solitary lifestyles?
Frugivorous diet requires large, spread-out territories.
What is ‘reciprocal altruism’ in chimpanzees?
Sharing food/coalitions with expectation of future returns.
How do lemurs adapt to Madagascar’s seasonal climate?
Torpor (low energy use) during dry seasons.
What is the ‘social brain hypothesis’?
Large brains evolved to manage complex social relationships.
Why do male mandrills have bright facial coloration?
Sexual selection (signals dominance and health).
What is ‘optimal foraging theory’?
Animals maximize energy gain while minimizing effort/risk.
How do chimpanzees hunt red colobus monkeys?
Coordinated group hunts with role specialization.
What is primate sociality?
“The tendency of primates to form complex, long-term social groups for survival and reproduction.”
Why is sociality important for primates?
“Enhances predator avoidance, resource access, and mating opportunities.”
What defines a primate’s social structure?
“The size, composition, and organization of their social group (e.g., solitary, pair-living, multi-male/multi-female).”
What is a dominance hierarchy?
“A ranking system within a group where individuals have varying levels of access to resources and mates.”
How do primates reinforce social bonds?
“Through grooming, play, and coalition formation.”
What is fission-fusion dynamics?
“A social system where group size and composition change temporarily (e.g., chimpanzees).”
What is kin selection?
“Behavior that favors the reproductive success of relatives, even at a cost to the individual.”
What role does grooming play in sociality?
“Strengthens alliances, reduces stress, and maintains hygiene.”
How do female primates influence social structure?
“Through matrilineal hierarchies (e.g., macaques) or resource defense.”
What is infanticide risk in primate groups?
“A strategy by males to increase mating opportunities by killing unrelated infants.”
What are the four types of primate communication?
“Vocal, gestural, olfactory, and tactile.”
How do vervet monkeys use vocalizations?
“Specific alarm calls for predators (e.g., ‘leopard,’ ‘eagle,’ ‘snake’).”
What is a “silent bared-teeth face” in primates?
“A submissive gesture signaling non-aggression (e.g., macaques).”
What is scent-marking used for?
“Territoriality, mating signals, and group cohesion.”
How do chimpanzees communicate aggression?
“Through pant-hoots, screams, and physical displays (e.g., branch shaking).”
What is multimodal communication?
“Combining multiple signals (e.g., vocal + gestural) to convey meaning.”
How do bonobos use sexual signals?
“To diffuse tension and strengthen social bonds.”
What is “lip-smacking” in primates?
“A affiliative gesture often used during grooming or reconciliation.”
How do gorillas communicate dominance?
“Through chest-beating, vocalizations, and direct eye contact.”
What is the function of “food calls”?
“To alert group members to the location of food resources.”
What is tool use in primates?
“Using objects (e.g., sticks, stones) to achieve goals (e.g., termite fishing in chimpanzees).”
How do capuchin monkeys demonstrate problem-solving?
“By cracking nuts with stones or using sticks to probe crevices.”
What is metacognition?
“Awareness of one’s own thought processes (e.g., opting out of difficult tasks).”
What is the “mirror test”?
“A test of self-awareness; passed by great apes and some monkeys.”
How do orangutans plan for the future?
“By hiding tools for later use or building nests in advance.”
What is social learning?
“Acquiring skills by observing others (e.g., potato-washing in Japanese macaques).”
What is theory of mind?
“Understanding others’ mental states (e.g., deception in chimpanzees).”
How do bonobos exhibit empathy?
“Through consolation behaviors (e.g., hugging after conflicts).”
What is numerical cognition?
“Ability to distinguish quantities (e.g., rhesus monkeys counting).”
What is the Aesop’s Fable paradigm?
“A test where primates drop stones into water to raise food (e.g., orangutans).”
What is the IUCN Red List?
“A global database assessing extinction risk for species, including primates.”
What is habitat fragmentation?
“The division of habitats into isolated patches, threatening primate populations.”
How does the pet trade impact primates?
“Drives illegal trafficking and population declines (e.g., slow lorises).”
What is bushmeat hunting?
“Hunting primates for food, a major threat in Africa and Asia.”
What are corridor habitats?
“Strips of land connecting fragmented habitats to promote gene flow.”
How does climate change affect primates?
“Alters food availability and habitat ranges (e.g., lemurs in Madagascar).”
What is community-based conservation?
“Involving local people in protecting primates and their habitats.”
What is reforestation?
“Replanting trees to restore degraded primate habitats.”
Why are lemurs critically endangered?
“Deforestation in Madagascar and hunting pressure.”
What is the role of ecotourism in conservation?
“Provides economic incentives to protect primates but risks disease transmission.”
