Bio Anthro Final

Four branches of Anthro

• Cultural anthropology

  • Study present-day societies in non-Western countries 

• Archaeology

  • Study earlier human societies → material remains (people, plant, structures)

  • Study processes behind human behaviors 

• Linguistic anthropology

  • Study the construction and use of language by human societies 

• Biological anthropology 

  • Study all aspects of present and past human biology 

Adaptive radiation

• The diversification of an ancestral group of organisms into new forms that are adapted to specific environmental niches

• Single species lead to multiple

Somatic cells

• Diploid cells that form the organs, tissues, and other parts of an organism’s body (body cells)

Gametes

• Sexual reproductive cells, ova and sperm, that have a haploid # of chromosomes and can unite with a gamete of the opposite type to form a new organism 

Microevolution

• Small-scale evolution, such as changes in allele frequency, that occurs from one generation to the next 

• In one single species

  • Macro → multiple species 

Menarche

• The onset of menstruation in an adolescent female (first period)

Melanin

• A brown pigment that determines the darkness or lightness of a human’s skin color due to its concentration in the skin 

  • (more UV, more melanin)

Primates and offspring number relative to nonprimates

• Fewer offspring with more investment 

Rhinarium

• Naked surface around nostrils, typically wet in mammals 

  • Strepsirrhines (lemurs, lorises) 

Strepsirhines

• Strepsirhines (lemurs, lorises)→ rhinarium, wet nose 

  • Tooth comb → digging into material 

Kin selection

• Natural selection in favor of altruistic behaviors that increase the fitness of donor’s relatives 

  • More invested to help if it is a relative 

Primate social organization (for example: polygyny, polyandry, monogamy, solitary)

• Polgyny 

  • One male, multi-female and offspring

  • Male has more than 1 partner 

  • Gorillas, orangutans, howler monkeys, Old world monkeys 

  • Sexual dimorphism 

• Polyandry 

  • One female, multimale and immature offspring

  • Males cooperate with the females in parenting activities  

  • Sexual dimorphism 

• Polygamy

  • Multimale, multifemale

  • Both mate promiscuously 

  • Competition low 

  • Old world monkeys, New world monkeys, chimpanzees

• All male

• Monogamy 

  • One male, one female  

  • Male invests large amount of time in young 

  • Gibbons, siamangs, two ceboids, many strepsirrhines 

  • Not much sexual dimorphism 

• Solitary 

  • Interaction between adult males and females is only for sexual activity 

  • Orangutans and few strepsirhines 

  • Lots of sexual dimorphism 

Visual predation hypothesis

• The proposition that unique primate traits arose as adaptations to to preying on insects and small animals 

  • Visual adaptations, intelligence, grasping abilities 

  • Insects, rodents, reptiles 

Angiosperm radiation hypothesis

• The proposition that certain primate traits, such as visual acuity, occurred in response to the availability of fruit and flowers after the spread of angiosperms 

Arboreal hypothesis

• The proposition that primates’ unique suite of traits is an adaptation to living in trees 

Anthropoid eye (fully enclosed or postorbital bar?)

• Fully enclosed eye sockets 

  • Protection of eyes for depth perception 

Cause of Miocene ape extinction (hint: cooler weather)

• Starts to cool and tropical forests recede 

• Ape species disappear 

• Climate change 

• Cooler, drier weather 

Diastema

• Gap between the lower canine and the third premolar 

  • Primates 

Hominin characteristics

• Diastema 

• Bipedal 

• upright posture

• bipedal locomotion

• larger and smarter brains

• specialized tool use

• communication through language

Hominin dental enamel

• Thick 

• Good for crushing food 

Patchy forest hypothesis

• Bipedalism arose in areas where the forest was becoming fragmented (end of Miocene)

• Food became more dispersed, more energy efficient once bipedalism freed their hands to pick up food 

Provisioning hypothesis

• Arms used to carry stuff around → explanation for bipedalism 

Biped vs quadruped body plan

• Biped

  • Foramen magnum (bottom of skull)

  • S shaped spine 

  • Short broad pelvis

• Quad

  • Back of skull

  • Tall narrow pelvis 

Benefits of bipedalism

• Travel greater distances

• Carrying food/resources 

• See further 

Robust australopithecines

• Large temporalis muscle

• Sagittal crest 

• Large face

• Small front teeth, large back teeth (molars, premolars)

Absolute vs relative dating

• Relative 

  • Relationship between items 

• Absolute 

  • Exact dates 

Hominin climate

• Less tropical 

• Drier, more seasonal open terrain 

Ape environment

• Short arms, long legs 

• Forest environments 

Taphonomy

• The study of the deposition of plat or animal remains and the environmental conditions affecting their preservation 

• Organisms after death 

• Investigate the life events of organism (crime scene)

Half-life

• The time it takes for half of the radioisotopes in a substance to decay; used in various radiometric dating methods 

Stratigraphy

• Top layer younger, bottom layer older 

Stone tools and genus Homo

• Creation of stone tools for hunting, etc

• Oldowan: The stone tool culture associated with H. habilis and, possibly, Au. garhi; characterized by the use of primitive chopper tools

Increase in brain and body of Homo erectus, why?

• Taller and heavier 

  • Climate change and impact on food supply 

• More protein 

• Carnivorous

  • Smaller gut 

  • More leisure time

  • Migration

  • cooking?

First hominid to leave Africa

• Homo erectus 

Control over fire for hominins

• Cooking 

  • Easier for digestion 

  • Kills off pathogens (tapeworm)

• Warmth 

  • Expand into inhospitable areas 

Homo floresiensis

• Dubbed the “hobbit” for its diminutive size, a possible new species of Homo found in Liang Bua Cave, on the Indonesian island of Flores

• Extremely small body size

• Southeast Asia 

• Teeth and mandible show variation in Middle Pleistocene  

Modern human cranium

• Tall, round 

• Chin that juts out 

Out of Africa model

• Single origin for modern humans and then left 

• Replace homo erectus population 

Neandertal locations

• Europe, western Asia 

Allen’s Rule and Bergmann's Rule

• Limb and body rules in cold and hot environments

Agriculture when and changes to teeth jaws and bone

Domestication costs and benefits

• More food per unit of land 

• Fewer and fewer people to make food 

  • People can do other things 

Sahelanthropus tchadensis

• The earliest pre-australopithecine species found in central Africa with possible evidence of bipedalism

• Small brain size 

• Massive browridge 

• Bipedal (foramen magnum)

• canine–premolar chewing complex was nonhoning

• Lived in a forest near a lake 

Uniformitarianism

• The theory that processes that occurred in the geologic past are still at work today 

• Earthquakes, erosion of water, island and mountain formation 

Darwin

• Came up with the theory of natural selection 

Wolff’s law

• the idea that natural healthy bones will adapt and change to adapt to the stress that it is subjected to

  • Tennis, weightlifting