BIO ANTH Notes PT 2 - Exam 2 study guide - Biological Anthropology PDF

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NOTES MIDTERM 2 “Species”: Biological concept – naturally occurring breeding population that is reproductively isolated, either actually or potentially from other groups Isolation Mechanisms - Premating: geographical, seasonal, habitat, temporal, courtship, and copulatory failure - Post-mating: no fertilization, zygote/fetal death, offspring sterilization (Horse + donkey = mule) Ring Species: No sharp barrier of hybridization - Separated geographically and changes shown over migratory routes - Not well adapted to environments - East & West Siberian Greenish Warbler: separated by change in song Fossils  Hard to tell about interbreeding from fossils TEMPO AND MODE Microevolution  selection, trait frequency; widely accepted Macroevolution  formation of new species; hard to see in nature/lab Anagenesis  population transitioning; not new branch Cladogenesis  new branches of life; new lineages Gradualism  Incremental chance over vast periods of time Punctuated Equilibrium  explains gaps and stasis in organism creation, and boom in new life Apparent explosive/static can come from lack of fossil records. Gradualism exists CLADISTICS: Ancestral: primitive; old traits Derived: new traits Unique: only for certain species Cladogram: reflects hypothesis about evolution - Independent Convergence  HOMOPLASY o Squirrels vs. Flying Squirrels - Some organisms are hard to classify: Pandas and bears: Red Panda, Raccoons - PHYLOGENETICS: resolves difficulties; reconstructs real patterns of relatedness through genetic code MAMMALS - Late Triassic (>200mya) - Milk producing mammary glands in females

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Subtle aspects of skull and mandible morphology Living Primate Relatives: tree shrews, Colugo (flying ‘lemur’)

Diverse Evolutionary Strategies: >300 species of primates; SET OF ADAPTATIONS from the product of Natural Selection that are suited for pursuing a particular lifestyle (dietary, behavioral, etc.) - Diversity in body size, morphology, behaviors - All Primates have… o Petrosally Derived Auditory Bulla o Complex/Large Brains – relative to body and skull size o Long lifespans o Mobile shoulders o Grasping hands and feet with 5 digits - Generalized body plan: Not hyper specialized - Binocular and Stereoscopic vision: Eyes on front head - Enclosed Bony Eye Orbits - Limb Mobility in Primates o Well developed clavicle o Greater in arboreal primates o Large range of motion and control - Reduced Dentition o Heterodont Teeth: Incisors, Canines, Pre-molars, molars o 2123 o Low, rounded molars for fruit eaters o Small incisors for leaf eaters o Sharp cusps for insect eaters - Life History o Altricial (useless) young o Extended juvenile period – not sexually mature o High investment in offspring - Diurnal  active during day - Social  live and associate in groups for some of their lives

THE PRIMATES STREPSIRRHINES – “WET NOSE” - Less derived from common ancestor - Unfused mandible - Post-orbital bar - Toothcomb  grooming - Olfactory communication  scent marking, secretions - Tapetum lucidum  eye shine, better vision at night Lemuriformes  Lemuroidea & Lorisoidea Lemurs  Madagascar

- 4 families - 40g-80kg - Wide range of diets, social systems Sifaka Lemur  Body proportions suited for leaping from tree to tree; can leap up to 30m Aye Aye Lemur  Hard to classify; one long finger for extracting yolks Subfossil Lemurs  Many extinctions within 2kya - Extremely derived; big weird lemurs died out Lorises + relatives  Asia (loris), Africa (Pottos and Galagos) - Eat fruit/insects/eggs - Usually nocturnal - Usually solitary, but varies by species HAPLORRHINES- “DRY NOSE” - Larger brains - Post-orbital closure - No toothcomb - Less prognatism - No tooth gap between canines and premolars TARSIFORMES- Tarsiers - Mixed traits between strepserhines & haplorhines - SE Asia / Indonesia - Only fully carnivorous primate clade o Insects, small animals, eggs - Mobile ears, eye cannot swivel - Vertical Climbing and Leaping: extended Tarsal bones - Prosimian features: Unfused jawbone, multiple nipples, grooming claws - Monkey Feature: No eye shine, dry nose, no tooth comb, monthly reproductive cycle PLATYRRHINES – “FLAT NOSE” - New World Monkey found in Central and South America - One super family  CEBOIDEA; 4-5 families - 2133 dental formula (except for Callitrichidae) - Prehensile tails Families - Callitrichidae: Marmosets and Tamarins o Family groups with 1 breeding female  Entire group assists with infants o Reversal  Claw-like nails o 2123 dental formula - Altidae: Howler Monkey, Spider Monkey, Murquis o Leaf/fruit diet o Prehensile, weight bearing tales

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Cebidae: Capuchin Monkey o Very large brain to body size ratio o Habitual tool users o Semi-prehensile tail Pithecidae + Aotidaes: Uakari & Saki + Owl Monkey

CATARHINES – “DOWNWARD NOSE” - Old World Monkeys found in Africa and Asia - Families  CERCOPITHECOIDEA & HOMINOIDEA - 2123 dental formula - Ischial callositics (hard butt pads) - Bilophodont Molar (two lobes/hills) w/ high cusps Families/Groupings CERCOPITHECOIDEA - Colobinae: “Leaf eating monkeys” o Sacculated stomachs + enlarged large intestines to digest cellulose o 1 breeding male / multi female groups o Colored infants - Cercopithecinae: “Cheek Pouch Monkey” o Multi-male/multi- female or 1M/multi female o Usually sexually dimorphic o Usually have dominance hierarchy o Exhibit estrous swellings HOMINOIDEA- Apes and Humans - Large Body - Large Brain - Curved fingers and toes - Sexually dimorphic - Rotating shoulder - No tails - 2123 - Y-5 Molar formula HYLOBATIDAE – Lesser Apes - Gibbons and Siamangs found in SE Asia - Omnivores - Ischial Caliosities (like Old World) - PAIR-BONDED but not necessarily monogamous - Hand over hand locomotion  brachiation - Arboreal

Hominoid Taxonomy Hominoid: all apes and humans; Hominid: humans and human ancestors

HOMINOIDEA: Apes and Humans Orangutans (Pongo) - Found in Sumatra + Borneo (SE Asia) - Extreme Sexual Dimorphic - Largest Arboreal Animal - Some tool use in captivity - Fruigivorous but also eat leaves flowers, insects, and small mammals - Quadramanual locomotion - BIMATURISM + NOYAU social system o 2 Strategies: Bruiser males and sub-males  large males walk through to keep other males away, but submales can sneak in. Little male can assume big male morphology Gorillas - African Apes, 3 species across Africa  mountain gorillas are rarest but most recognized - Extreme Sexual Dimorphism - 1 male/ multi female groups - No meat eating but not vegetarian - Sympatric with chips in many parts of Africa - KNUCKLE WALKING Chimpanzees (Pan) - Sub-Saharan Africa - Fruit dominated but Omnivorous - Multi-male/female groups - Strong Male-Male bonds + hierarchy - Social Customs are SHARED, LEARNED BEHAVIORS

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Group “warfare”, infanticide, cannibalism KNUCKLE WALKING

Bonobos (Pan Paniscus) - Equatorial Africa - Fruit dominated but omnivorous - MULTI M/F groups - Strong bonds between unrelated females AND mothers and sons - Use of non-reproductive sex  cement bonds. No discrimination of age or gender - Virtually no habitual tool use in wild - KNUCKLE WALKING

PRIMATE BEHAVIOR + ECOLOGY Primatology  study of non-human primates Behavioral Ecology  Study of animal primates from an evolutionary perspective in a natural context PARADIGMS FOR STUDYING ANIMALS SOCIAL BEHAVIOR Sociobiology  understand social behavior in terms of individual fitness/reproductive success New Synthesis  E.O. Wilson: Animals are selfish; individual motivation to survive - Early models tended to treat all patterns of behavior as ADAPTATIONS Behavioral Ecology  Tested + refined sociobiology theory - Interaction between phenotype and environment - PHENOTYPIC TRAITS AREN’T DIRECTLY RELATED TO NATURAL SELECTION Infanticide  killing babies of own species; often done by high rank males - To mate with females who are currently investing in offspring - Females defend by paternal confusion Primate Social Systems: - Noyau  solitary female with strong male - 1 Male / 1 Female - Cooperative Breeding  One breeding female, many males - One Male group + all male bands  ousting resident male - Multi M/F Group  live and travel together - Multilevel Society  Smaller interior groupings - FISSION/FUSION SOCIETIES  Females travel alone. Come together into subgroups. Males sometimes come together o Chimps, Bonobos, Spider Monkeys o Female associations vary with food abundance o HQ food o Males  Cooperate with other males to defend community  Compete within community with other males when female are sexually receptive

Food competition  most salient for females Reproductive  mating opportunities and infant care/protection Predation Risk Phylogeny  array of morphology adaption WHY BE SOCIAL? Benefits  Safety, easy to find a mate, access to resources, potential for cooperation  advancing self-interest in-group Costs  Sexual competition, resource competition, greater visibility to predators Dominance Hierarchies Priority of Access  Who gets ‘x’ if there isn’t enough x to go around? Dominant vs. Submissive  Dominance gets food first Despotic vs. Linear  one guy/girl in charge VS. Progressive ranks from top to bottom HIERARCHIES SHIFT INTRASEXUAL COMPETITIONS (Usually male/male) - Physical combat - Sperm Competition - Pursue/hold high rank - Alternate male strategies  Bimaturism - Infanticide - Costly signaling INTERSEXUAL (male-female) - Male coercion o Physical Intimidation o Infanticide - Female Choice o Drives costly signaling o Physical ornaments o Behavior/courtship SCRAMBLE VS CONTEST COMPETITIONS How are resources like food distributed in time and space? How does this influence behavior? Organisms that eat rare, HQ foods  AVOID COMPETITION - Travel alone with offspring - Some females travel in groups to defend resources Organisms that eat abundant low quality food  Travel in groups - Sorting food is less intense - Leaves are less valuable Social Systems and Morphology - Males have greater variance in reproductive success  Lots of potential for offspring, but some may have more than others - Females aren’t passive

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o Reproductive errors are more costly o Estrous Swellings Cooperation  infant care/protection, hunting, coalitions

INCLUSIVE FITNESS Coefficient of Relatedness  Safeguard genes that you have in yourself Kin Selection  animals behaving preferentially towards genetic relatives - rb>c - explains altruistic behavior - Motivated to defend group more than their own survival FAVOR COOPERATION Mutualism  Both participants benefit, cost is low or none Inclusive Fitness Repeated Encounters  Opportunity for reciprocity, track good partners Maybe it feels food to share? Sharing  Oxytocin reward THEORIES ON PRIMATIVE INTELLIGENCE Ecological  spatial memory; location and status of food resource Extractive Foraging, tech, culture  acquisition of learned skills/behaviors Social or “Machiavellian” intelligence  ability to track complex social relationship; recognize fairness/inequalities

PAN REVISITED  Chimps (4 sub species) and Bonobos (1 species) ; Central Africa; ENDANGERED Major threats  deforestation; pet trade; bushmeat trade; disease (AIDS) Physiology  Moderate sexual dimorphism (~15%); overlap in body size; prolonged juvi/adol period GOMBE: FRODO  37, 1st alpha male; killed human child and got sick FREUD  42, 2nd alpha male; sweet, non aggressive FERDINAND  23, 3rd alpha extremely infanticidal FUDGE  upcoming alpha, even temper SOCIALITIES Similarities  Fission – Fusion; promiscuous mating; estrous swellings Differences: - Chimps: o Male are social sex o Strongest bonds  males o Adult males dominate females o Infanticide/Cannibalism o Aggressive

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Bonobos: o Females are social sex o Use sex instead of aggression o Females dominate males

DIET Similarities  Frugivorous; eat pith, flowers, insects, meat, small mammals Differences: - Chimps: o Hunting common, but varies o Favor arboreal primates o Male biased - Bonobos: o Hunting widespread + low frequency o One community captures monkeys and plays with them; one community will eat them CHIMPS AND BONOBOS ARE APES THAT…. Thrive in a variety of modern environments, and exhibit very different social/cultural dynamics despite very close evolutionary history. CHIMPS AND BONOBOS ARE NOT APES THAT… Are “less evolved” forms of human.

PALEOANTHROPOLOGY  study of primate/human evolution 1. Fossils: diet, aspects of behavior, organism morphology 2. Dating Methods A. RELATIVE  What is younger/older? i. Original Horizontally: things tend to stay where buried ii. Superposition: older things will be found in lower strata iii. Cross cutting relationships: older features have to exist before events or features can modify them a. Lithostratigraphy  compare rock strata in different locations i. Identify major geographical/ecological events b. Biostratigraphy  litho but with fossils i. Use pig teeth c. Chemical Dating  Bones from same location/time should have same chemical signatures i. Fluorine Dating: present in the environment, coats things in earth d. Paleomagnetism  sediments that contain iron orient N-S; magnetic north changes, shift establishes time range B. ABSOLUTE a. DENDROCHRONOLOGY  tree rings i. Width of rings tells you what happened during year b. RADIOMETRIC DATING  Rate of Decay of an isotope

i. Half life ii. Carbon 14 (Organic material...