Human Evolution Flashcards
Hominid
Any member of the group consisting of all modern + extinct humans and great apes
Classify
Arrange a group of people in classes or categories according to shared qualities or characteristics
Taxonomy
A hierachiacl system for classifying and identifying organisms
Species
Only organisms in the same species can produce fertile offspring - presumes you are in the same genus
Hominid Evolutionary trends
Directional change in a character state, or set of character states resulting in a significant change through time
Evolutionary trends examples
- Relative size of cerebral cortex
- Mobility of the digits
- Prognathism + dentition
- Locomotion - Adaps to bipedalism + quadrupedalism
Relative size opf cerebral cortex
Cerebrum responsible for complex functions - vison, memory, reasoning + malipulative ability. Larger the cortex more accurate visual + tactile perception
Number of cerebral convolutions increased
Permits greater surface area of cortex - effects on development.
Relative size of cerebral cortex
Average increase in cerebrum in particular the cerebral cortex - frontal lobe
Mobility of digits
Primates are pentadactyl (5 digits per limb). Hihg mobile due to arboreal - living in ttrees.
Evolutionary trends - digits
Increasing ability to mnove digits independantly of one another - most evolved = thumb - independent and opposable.
Power Grip
Is carrying or grasping task where fingers flex towards palm - most forceful grip
Precision Grip
Object pinched between thumb and fingers - fine motor skills
HUman Lacking opposable big toe
Dont live in trees, no need to grip branches - uses to balance
Prognathism
Projecting lower jar or chin. Human jaw is smaller than apes - better centre of gravity
Dentition
Dental arch - Humans are parabolic + teeth are similar in height. Apes have parllel sides + large canine teeth.
Dentition trend
Towards smaller more uniform teeth and more rounded parabolic shape
Locomotion
Adaptations and bipedalism and Quadrupedalism
Upright stance
Walk upright with a standing gait - humans require modified muscle/skeletal structure
Postural adaptations
Position of foramen magnum, curvature of spine, pelvis shape, carrying angle of femur, knee structure, foot structure
Position of Foramen Magnum
Large hole in base of skull - humans centred, apes further back.
Central foramen magnum benifits (humans only)
Enables skull to balance ontop of verebral column - require less neck muscles
Human jaw is smaller - allows kull to balance, aproix same weight on either side
Curvature of spine
Non humans have a single curved (c shape) spine - body tilts forward. Centre of grav. chest level. HUmans have S shaped spine - centre of grav. runs straiught through head and spine
Pelvis shape
Human = Shorter and broader. Allows for larger buttock muscles to attach. Allows fumar to attach further appart Apes = long and narrow.
Carrying Angle
Hip joint directly under body. Allows weight to be transfered to legs. Converge towards knees (not direcly verticle). Allows weight distribution to remain close to body when walking
Knee structue
Weight of body transmitted to outside of femur to knee.
Foot structure
No opposable toe. Longitudinal arch and Transverse Arch
Muscle tone
Continuois and passive contraction of muscles
3 species of Australopithecines
Afarensis, Africanus, Paranthropus Robustus
Australopithecus Afarensis
4-3 million years ago. 1-1.2 metres tall, 25-30 kg. LUCY. SMall brain, nomadic, herbivores, no tools
Australopithecus Africanus
3-2.5 million years ago, 1.3m, slightly larger brain, no tools, nomadic, diet similar to chimps
Paranthropus Robustus
2-1.5 million years ago, sagital crest to anchor muscles, alrger brain, 1.5m tall, pebble tools, nomadic shelters, herbibores.
Homo Habilis
2.5-1.5 million years ago. 650-750 cc. Travels for food, Teepee shelters. Boine marrow, small animals, fruits. First to make tools. Not specific
Homo Erectus - Upright man
1.5-250000 years ago. 850-1200cc, sometimes used caves as shelters. Required a lot of energy - meat and protien. Acheulean tools. Earliest evidence of campfire
Acheulian tools
Tear shaped tools - hand axes. More sophisticated than oldowan tools
Campfire Uses
Keep away predators, give warmth + light, extend daylight activities, cooking, hunting animals
Homeo Neanderthalensis
200,000-35,000 years ago. Brain capacity: 1500cc. Shelter - used caves or constructed out of wood, tusks and skins. Food - plant food decreases, meat increases. Sophisticated stone tools. First to show variety. First humans to wear clothes
Homeo Sapiens - Wise man
300,000 to present. Brain capacity - 1300cc. Lived in shelters, produced own food. variety of animal + plant food. Made smaller, more complex tools. Fish hooks, bows and arrows. Bone and Ivory and antler tools
Paleolithic tools
Aurignacian, solutrean, magdaleanian.
Aurignacian tools
43-26 thousand years. long thin flakes have been removed. antler and bone used occasionally
Solutrean rools
22-19 thousand years, sophisticated retouch by pressure flaking on flint that has been heat treated to be more workable
Magdalenian tools
18-12 thousand years ago. Bone and antler over stone. Using a burin (chisel). collection of needles, barbed spear points, spear throwers and range of tools.
Tools trend
More evolved, more chips and smaller chips taken out.
Other culture - Homeo sapiens
Exchanged resources over wide areas. Created music, art, personal adornment, ritual complex symbolic world.
