Exam #2 Anthro

Phylogeny

A diagram showing evolutionary relationships among organisms sharing a common ancestor; example: humans and chimpanzees share a recent ancestor

Systematics

The process of constructing evolutionary relationships among organisms; example: using DNA to build evolutionary trees

Taxonomy

The classification and naming of organisms based on relationships; example: Homo sapiens classification

Analogous traits

Traits similar due to function not shared ancestry; example: wings of birds and insects

Homologous traits

Traits similar due to shared ancestry; example: human arm and monkey arm

Ancestral traits

Traits appearing early in a lineage; example: tails in early primates

Derived traits

Traits modified from ancestral conditions; example: apes lacking tails

Cladistics

A method grouping organisms using shared derived traits; example: grouping apes by no tail

Microevolution

Genetic change within a population across generations; example: variation in fur color

Macroevolution

Evolutionary change resulting in new species; example: one species splitting into two

Biological species concept

A species is a group that can interbreed and is reproductively isolated; example: dogs of different breeds

Allopatric speciation

New species form due to geographic isolation; example: populations separated by a river

Reproductive isolation

Inability of populations to interbreed; example: separated groups no longer mating

Genetic divergence

Accumulation of genetic differences over time; example: isolated populations evolving differently

Potassium Argon dating

A method dating volcanic rock using radioactive decay; example: dating layers around fossils

Plate tectonics

The movement of Earth’s crustal plates; example: continents shifting over time

History of life

Major sequence of evolutionary events; example: fish evolving before amphibians

Tetrapod origins

Four-limbed animals evolved from lobe-finned fish; example: early amphibians

Amphibians to reptiles

Reptiles evolved from amphibian ancestors; example: adaptation to dry land

Synapsid reptiles to mammals

Mammals evolved from synapsid reptiles; example: mammal-like reptiles

Dinosaurs to birds

Birds evolved from dinosaurs; example: Archaeopteryx

Niche

The role and lifestyle of a species in its environment; example: predator vs prey

Adaptive radiation

Rapid diversification into available niches; example: mammals after dinosaur extinction

Paleospecies

Fossil species identified by morphology; example: skull differences

Sexual selection

A type of natural selection favoring mating success; example: bright colors or fighting

Intersexual selection

Mate choice usually by females; example: females choosing strongest males

Intrasexual selection

Competition within one sex; example: males fighting

Canine size sexual selection

Larger canines evolve due to male competition; example: dominant males

Body size sexual selection

Larger body size increases mating success; example: bigger males win fights

Testes size sexual selection

Testes size relates to sperm competition; example: larger testes with multiple mating

Infanticide adaptive explanation

Males kill infants to shorten female reproductive cycles; example: new dominant male

Altruism

Behavior benefiting others at a cost; example: food sharing

Kin selection

Helping relatives increases genetic success; example: grooming kin

Reciprocal altruism

Helping others expecting return; example: trading favors

Biological continuum

Humans share traits with other primates; example: chimpanzee tool use

Primate intelligence context

Intelligence linked to ecological and social pressures; example: remembering fruit locations

Primate language context

Human language builds on primate communication; example: vocal signals

Primate culture context

Socially learned behaviors across groups; example: chimp traditions

Primate hunting context

Some primates hunt cooperatively; example: chimp hunting

Primate intergroup conflict

Territorial aggression seen in primates; example: chimp raids

Chimpanzee learning

Learning through observation; example: watching tool use

Human learning

Learning through teaching imitation and observation; example: classroom learning

Primate characteristics

Grasping hands nails vision large brains; example: monkeys gripping branches

Angiosperm plants

Flowering plants producing fruit; example: fruit influencing primates

Dental formula 2 1 2 3

Old World monkeys and apes; example: humans

Dental formula 2 1 3 3

New World monkeys; example: spider monkeys

Primate origins

Theories including arboreal visual predation angiosperm; example: tree adaptation

Plesiadapiformes

Early primitive primate-like mammals; example: squirrel-like animals

Adapoids

Early primates linked to strepsirrhines; example: lemur-like fossils

Omomyoids

Early primates linked to haplorhines; example: tarsier-like fossils

Primate locomotion

Movement types like brachiation and bipedalism; example: gibbons swinging

Strepsirrhines

Wet nose tooth comb smell reliance; example: lemurs Madagascar

Haplorhines

Dry nose vision reliance larger brains; example: humans monkeys

Platyrrhines

New World monkeys broad nose prehensile tail; example: spider monkeys

Cercopithecoidea

Old World monkeys bilophodont teeth; example: baboons

Hominoidea

Apes no tail Y-5 molars; example: chimpanzees

Gibbons

Small apes brachiation monogamy Southeast Asia; example: swinging

Pongo pygmaeus

Orangutans solitary arboreal; example: fruit eating

Pan troglodytes

Chimpanzees tool use hunting fission fusion; example: termite fishing

Pan paniscus

Bonobos peaceful female alliances; example: social bonding

Gorilla gorilla

Gorillas one male groups leaf diet; example: silverback leader

Fayum Egypt

Early primate fossil site; example: Aegyptopithecus

Catopithecus

Early primate with 2:1:2:3 dental formula; example: Fayum fossil

Aegyptopithecus

Early anthropoid with OW dental formula; example: Egypt fossil

Apidium

Early primate with NW dental formula; example: platyrrhine ancestor

Postorbital bar

Bony eye ring in all primates; example: lemurs

Postorbital closure

Bony eye plate in haplorhines; example: monkeys apes

Wet nose trait

Moist nose in strepsirrhines; example: lemurs

Tooth comb trait

Grooming teeth in strepsirrhines; example: lemurs

Prehensile tail

Grasping tail in NW monkeys; example: spider monkeys

Bilophodont teeth

Molars with two ridges in OW monkeys; example: baboons

Y 5 molars

Five cusp molars in apes; example: humans

Miocene hominoids

Fossil apes from Miocene; example: Proconsul Dryopithecus Sivapithecus

Proconsul

Early ape no tail monkey-like movement; example: branch walking

Dryopithecus

First modern ape body plan long arms; example: swinging

Sivapithecus

Orangutan relative thick enamel; example: similar face

Victoriapithecidae

Early Old World monkeys with bilophodont teeth; example: Miocene monkeys

Diet body size relationship

Larger primates eat lower quality foods; example: gorillas vs tarsiers

Frugivory diet traits

Large incisors low cusps; example: fruit eaters

Folivory diet traits

Shearing teeth large gut; example: leaf eaters

Insect diet traits

Sharp cusps simple gut; example: insect eaters

Female reproductive strategy

High investment pregnancy lactation; example: fewer offspring

Male reproductive strategy

Compete for access to females; example: fighting

Reversal of fortune Miocene

Monkeys replaced apes due to climate change; example: monkeys adapt to dry habitats

Paternal investment factors

More care when offspring survival depends on it; example: shared parenting

Benefits of social groups

Protection and resource access; example: predator detection

Costs of social groups

Competition disease; example: fighting over food

Solitary

Individuals live alone; example: orangutans

One male polygyny

One male multiple females; example: gorillas

Multimale polygyny

Multiple males and females; example: baboons

Monogamy

One male one female; example: gibbons

Polyandry

One female multiple males; example: rare primate system

Fission fusion

Groups split and rejoin; example: chimpanzees

Female dominance hierarchy

Based on resource access; example: better food

Male dominance hierarchy

Based on access to mates; example: dominant male breeds more