Evolution Study notes

1. Evolution of Humankind
Fossil Hominids from South Africa-the Cradle of Mankind
 Hominid
- Biological group include humans, human-like animals (gorilla, chimps, orang-utans, our
ancestors)
 Sterkfontein richest Hominid fossil site-World Heritage site known as Cradle of Mankind
- Cold be because depression in ground people pushed-mud slide
Hominid studies depend on:
 Fossilised remains
 Genetic evidence (mitochondrial DNA through mother’s line)
 Archaeology
Trends in Human Evolution:
Human biological evolution:
 Skeletal changes linked to bipedalism
- Morphological alterations – arrangement and size of bones, hip size and shape, knee
size, leg length and shape/orientation of vertebral column
- More delicate skeleton
- Shift foramen magnum to more forward position
- Rounder skull
- Increased cranium size-develop language and intelligence
- Flatter face-less sloping forehead, small eyebrow ridges (usually absent), less protruding
jaw, more developed chin, more rounded jaw, change in dentition
 Advantages bipedalism:
- Free arms completely (use/make tools more efficiently, stretch fruit, pick fruit, seeds in
trees, use hands social display communication)
- See further over savannah grass (better nutrition) however more easily seen by
predators
- Foraging/scavenging out in open savannah bodies exposed less sunlight (better
temperature control)
- More energy efficient walk on two legs-energy reproducing
 Changes in skull and endocranial features
- Large brain outcome substantial energy saving development ie:bipedalism
- Bipedalism change energy/fat allocation in body-additional energy brain
 Changes in manipulative ability of hand (fine motor skill)
 Walking upright
- Adapt to climate change cooling globally
- Rainforests in Africa replaced savannah, patches woodland
- Tree climbing apes more adept walking-rewarded shrubs, carcasses, roots in savannah

2. Evolution of Humankind
Human cultural evolution:
 Living socially co-operative groups-increased chances of survival
 Use of tools (stone, wood, bone)
 Parenting
 Fire (manipulate environment suit us)
 Shelter
 Clothing (occupy more niches)
 Abstract thought (communication, language, art)
 Increase intelligence-taught behaviour adapt changing climate
 Food-gathering
 Domestication of plants and animals
Note: Hominids are bipedal animals in fossil record showing mixture ape-like and human-like feature
Characteristics shared with apes:
 Opposable thumb
 Bare finger tips
 Long free rotating arms
 Stereoscopic vision
 Eyes cones/rods
 Large brains compared to body mass
 Portion of brain centres that process information from hands and eyes enlarged
 Olfactory (smell) brain centres diminish
 Dentition similar monkeys/apes
 Jaws teeth gentle curve
 Few offspring, long parental care
Characteristics that make us different from other primates:
 Always bipedal
 Flat face (senses closer brain)
 Large brain
 Opposable thumb (power/precision grip) Note: Apes-only power
 Complex language, writing, technology
 Sophisticated culture suggest consciousness lacking apes (art/jewellery)
- Cro-magon culture
- Tool kits more sophisticated, wider variety raw materials (bone/antler)
- New implements making clothing, engraving and sculpting
- Fine art ie: decorated tools, beads, ivory carving humans/animals, clay figurines, musical
instruments, cave paintings
- Found Blombos caves, Pinnacle point, Border cave, Southern Africa

3. Evolution of Humankind
Patterns of dispersal:
 Modern man preceded by evolutionary forms of Hominid showed bipedalism
 Archaic man (habilis and erectus) and modern man (Homo sapiens sapiens) characterised
enlarged brain cases and use of tools
Australopithecus afarensis:
 >3mya
 Example of Lucy
 Awash Valley (Ethiopia)
Australopithecus africanus:
 >3mya
 Taung child discovered by Raymond Dart
 Mr Ples from Sterkfontein Caves in Cradle of Humankind discovered by Dr Robert Broom,
Raymond Dart, John Robinson
 Little Foot discovered by Ron Clarke
 Laetoli footprints discovered in volcanic ash in Tanzania
Australopithecus sediba:
 Latest find placed between Australopithecus and Homo species
 Discovered Malapa Fossil Site Cradle of Mankind by Professor Lee Berger
 Transitional species
- A lot of argument/controversy
- Link theory together
- Lead to weight of gradual change (show shifts from one form to another)/common
ancestor
Homo habilus:
 2mya
 Handy man/first tool maker
 From Lake Turkana (Kenya) and Olduvai gorge (Tanzania)
Homo erectus:
 1.5mya
 Disputed ancestor of humans and Homo neanderthalensis
 Found in Europe
Homo sapiens:
 100000-25000mya
 Example Border cave in KZN, Klasies river mouth

4. Evolution of Humankind
 Earliest use of fire to make ochre artefacts at Blombos cave and Pinnacle cave (Mossel Bay)
 San as world’s oldest extant people
Migration of modern humans around the world:
 Both theories state climate played huge role man movements
 Follow prey
 Changes sea level during ices ages led to land bridges developing-allow migration, across
seas, inhabit new continents
 Resources limited/more hospitable climate
 Early humans strandlopers-migrate along shores living off sea
Multiregional Continuity Model:
 After Homo erectus left Africa, dispersed portions of Old World
 Regional populations slowly evolved into modern humans
- Groups were isolated
- Climate pressure, ocean levels rise, spontaneous change
This model suggests that:
 Some level gene flow between geographically separated populations prevented speciation
after dispersal
 All humans derive from Homo erectus
 Natural selection regional populations since original dispersal is responsible for regional
variants (races)
 Emergence of Homo sapiens not restricted one area, phenomenon occurred throughout
geographical range where humans lived
Out of Africa theory:
 Most widely accepted
 Modern humans evolved recently out of Africa
 Migrated into Eurasia and replaced all populations which had descended from Homo erectus
- Homo erectus from Africa migrated to Europe and Asia
Critical to this model are:
 Homo erectus colonise large portion planet
 Changes occur
 Genetic and fossil evidence interpreted to show that archaic Homo sapiens evolved to
anatomically modern humans in Africa (200 000-150 000 years ago)
- Mutations in Africa especially Homo sapiens
 Successful second wave Members one branch of Homo sapiens left Africa (125 000-60 000
years ago) over time these humans replaced earlier humans ie: Neanderthals/erectus
 Homo sapiens co-habited with Homo erectus eventually outcompete them/adaptable so
colonise quickly
 DNA testing early humans interbred Neanderthals

5. Evolution of Humankind
 Date earliest out of Africa migration (earliest migrants with living descendents)-60000 years
ago suggested by genetics
 Migration out of continent could have taken place 125 0000 years ago according to Arabian
archaeology find tools in region
 Modern human variation relatively recent phenomenon
Alternatives theory evolution:
 Intelligent design
- All living forms intelligently designed by supreme being
- Evidence scientific based not faith based
 Creationism
- All living forms created by God (image)
- Some explanations in form of stories (Zulu/San)
Note: All humans genetically very closely related to each other and to primates