Final Review

Know austra afarensis

homo erectus

neanderthal

sapiens


Sahelanthropus tchadensis

  • Chad, Africa

  • dated 6 - 7 MA

  • bipedal

  • smaller canines than living apes

  • chimp sized brain 370 cc


Bipedal Complex:

  • Skull: foramen magnum position toward center of skull

  • Spine: large and curved lower spine so body balanced above hips (lumbar lordosis)

  • Pelvis: short and broad and laterally flared, with changes in muscle attachments

  • Femur: longer, stouter, angled toward center line with larger joint surfaces

  • Foot: enlarged big toe in line with others, stiff midfoot, arch


Bipedalism and canine reduction first

brain expansion and language were later


why bipedalism?

  • arboreal feeding

  • ground feeding

  • energetic efficiency in open landscape

  • thermoregulation

  • carrying stuff


3 genera Pliocene

  • Australopithecus (only plicocene)

  • Paranthropus (start in Pliocene, continues into Pleistocene)

  • Homo (starts in Pliocene, continues into Pleistocene


Australiopithecus afarensis

  • 3.6 - 3 Ma

  • woody grassland

  • bipedal

  • brain 450 cc, slightly bigger than chimp and earlier hominins

  • high sexual dimorphism (males 50% bigger)

  • Lucy skeleton

  • throughout africa

  • skull and dentition intermediate between apes and humans

  • relatively large incisors but smaller than modern apes

  • Diastema, large jaw, and cheek bone

  • S shaped spine, pelvis, femur, and foot indicate fully bipedal when on ground

  • evidence they also climbed, maybe to protect from predators or sleep at night

  • mature faster than homo sapien


Paranthropus

  • side branch of human evolution, not direct ancestor

  • very robust

  • sagittal crest

  • big chewing muscles

  • zygomatic arches

mode 2 tools


Differentiate Austra from early hominis

  • early homo had stone tools present at all sites

  • early homo had flatter face and smaller teeth and 550 - 800 cc


Homo erectus

  • stone tool use mode 1 and 2

  • larger brains

  • larger frontal cortex

  • less sexual dimorphism

  • taller, long distance running

  • eating meat, maybe hunting

  • extractive foraging

  • NOT controlling fire

  • NOT making symbolic/decorative objects

  • first homo outside Africa

  • moving toward human like social lives: Cooperation, division of labor, slower life history


Oldowan tool industry (mode 1)

  • begins 2.6 mya

  • make flakes by knocking a hammer stone into a core

  • both the flakes and the sharp edged cores were used as tools


Acheulean tool industry (mode 2)

  • 1.75 mya

  • made by homo erectus

  • Oldowan tools still around

  • bifacial, more symmetric handaxes


Food sharing

  • juveniles are net consumers

  • middle age men and postmenopausal women are producers of surplus

  • men self sufficient at age 17

  • Women self sufficient late 40s


Pleistocene: environment getting colder and more volatile

Increased environmental fluctuation→ need for cognitive capacities to find solutions to novel problems → larger brains, more complex tech, broader and more diverse diet


Homo Heidelbergensis:

  • 600 - 300 kya

  • Derived features: brain size 1200 - 1300 cc, higher foreheads, more rounded skull, sides of skull more vertical

  • Ancestral features: large brow ridges, thicker cranial bones, larger more prognathic face, no chin, robust bodies

  • Mode 3 tools

  • Large game hunter using hafted tools like spears

  • Hand axes less common

  • Levallois technique: flakes made with prepared cores. the Core is not a tool itself


Homo floresiensis

  • 700 - 60 kya

  • small bodied, 3 feet tall

  • 400 cc chimp sized brain

  • Mode 1 tools

  • hunted animals

  • no chin, moderate brow ridge, sloping forehead

  • made and used stone tools, hunted animals, may have used fire


Sima de los Huesos, Spain

  • Heidelbergensis becoming Neanderthals


Neanderthals

  • Europe and Asia

  • 300 - 40 kya

  • oldest jewelry in the world including eagle talons, notches, polished facets, smoothed cut marks

  • oldest cave makers

  • none lived past 40-45 yrs

  • many skeletons show evidence of disease and injury

  • care for the disabled and sick

  • medical care of plants


Denisovans

  • 300 - 55 kya

  • Russia and Siberia

  • DNA from pinkie fragment

  • DNA from teeth

  • teeth = huge molars

  • sister species to Neanderthals


Basal homo sapiens: closer to split with Neanderthals, mix of primitive and derived features


Middle Stone Age

  • africa only term and human specific

  • European record called it middle paleolithic

  • 250 to 40 kya

  • mostly mode 3 tools

  • evidence of human populations networking over large distance

  • ornamentation and symbolic expression


major migration out of Africa was 60 kya


Upper Paleolithic tech and culture

  • starting 42 kya

  • Europe

  • dozens of distinctive tools kits emphasizing mode 4 tools which were blades

  • large tool diversity

  • different raw material used in tool making

  • raw material transported for long distances


Chauvet Cave 36 kya

  • cave art from Homo Sapiens


Bergmann’s rule: larger bodies found in colder areas and smaller bodies in warmer areas


Lactose Intolerance:

  • lactase persistence

  • North Europe and North Africa

  • single, dominant gene

  • two mutations in different populations by convergence

  • Pastoralists


Genetics of disease:

  • mutation-selection balance: new mutations may create the deleterious allele as fast as selection eliminates it

  • Heterozygote advantage: balanced polymorphism where the heterozygote has a higher fitness than either homozygote

  • mismatch (aka diabetes)


Humans and chimps only differ 1.2% in DNA


Understanding how we think and behave:

  • natural selection can shape the genetic underpinnings of learning and how behaviorally flexible an organism is


Environments of Evolutionary Adaptedness:

  • majority of human history spent as hunter gatherers and many of our complex adaptations are tailored for reproductive success and survivorship in hunting/gathering lifestyles


The 3 Cs: Cognition, Culture, and Cooperation