Human Evolution 1, 2 & 3 Flashcards
Summarise characteristics of the 3 major genre
o Australopithecus (biped, gracile, small brain) o Parathropus (biped, robust crania, small brain) o Homo (biped, gracile, relativley larger brain)
- Evolutionary themes (in order of occurrence)
- Locomotion
- Cooling drying climate; expansion of savannahs - Diet
- thin to thick enamel
- Reduced canines
- Reduced prognathism - Brain
- Cranial capacity
- Fluctuating climate
why do humans and chimps share common traits
- Shared common ancestor (E.g. Y5 molars No tail)
2. Convergent evolution (E.g. Male cooperation and Warfare)
Describe 3 mid-late miocene hominoid traits
Prognathism: condition in which part of face below nose is pushed out, relatively wide angle
Brachiation: method movement that uses arm to swing from branch to branch
Diastema: space b/w upper canin and incisor that accomodates the lower canine
when was locomotory transition from arboreal to bipedal originated
3.8 mya
Australopithecines (3.8mya) had cooling climate, how did this cause bipedalism (4 ways)
- postural adaption to feeing
- thermoregulatory (reduce surface area for insulation)
- energetic of movement over open ground
- carrying objects
whats the wading hypothesis of hominin bipals
o Aquadic theory of bipedality
describe the footprints of laetoli
- Evidence of bipedalism:
o Australopithecus
o Big toe less opposable / reduction of smaller toes
o Arch
what divergence occurred around 2.5-1mya
- Around 2.5-1mya: Divergence of ‘masticators’ & ‘brains’
o = diversity of hominins
o 3 genus at same time
what trait is prominent in paranthropus
large molars
large masticatory muscles attached on sagittal crested mandible
Summerise 5-2mya : eAST + south africa
bipedal= remodelling of lower limb
thicker enamel= diet shift to harder more fibrous
Earlu homo - Why does face become smaller and flatter over evolutionary time?
- Diet- main reason
o Cooking allowed softer food - Increased brain size
- Bipedalism
Describe oldowan stone tools (
h. habilis
Define: simple flake tools struck from core
H. habilis social discoveries
- Cut marks on bones > hunting
- Concentrations of bones and stones suggest central place foraging
o Carrying meat back to a central camp - Evidence of home bases
o Also argued that they are butchering sites
extinction of paranthropus happened at what time and at same time as
1.8- 0.5 mya: radiation of Homo ergaster & h. erectus
describe acheulian tools
o 1.6 mya
o Clearly associated H ergaster
o Standard forms (bifaces) , teardrop w/ sharp point
♣ Hand axes, cleavers
o Persist for 1 mya- little change
o Stayed with ergaster in africa (didn’t take culture to asia)
Descibr h. ergastur in africa
- 8-0.5mya(?) – Acheulian tools
- controlled fire
- hunting of large mammals
- Some disperse from Africa early to Eurasia and Asia
Descibr h. erectus in asia
approx. 1.6 - 0.2 mya
- less complex tools than H. ergaster
- controlled fire
- dead end group but persists longer than H. ergaster
what did homo ergastur probably give rise to
h/ heidelbergensis
describe origin and movement of heidelberdnensis
- From erguster
- Left africa Moved to Europe and asia
desire socials of heidelberg
Evidence for hunting: • Wooden spears found • Ca 400 000 'Beach Huts' • Earliest documented shelter • 350 000
3 out of africa events
(caused by changes in climate)
- Ergaster > became erectus in asia
- Heidel >
- Homo sapiens
why did out of africa events require larger brains
• needed to be successful in new/changing environment)
neanderthal lifestyle
- Hunted large game
- Buried dead -
- Lived in cave
- Possible cannibalism (bone marrow eaten + burning)
- Mousterian tool industry
describe cro magnon
Early H. Sapiens (50-30kya) lifestyle
• Europe
• Decorative art, figurines, more complex tools (upper palaeolithic culture- antler, bone), raw material transport (trade), shelters, burials
explain the obstetrical dilemma
humans= bowl shaped pelvis
- for bipedal. but restricts birth canal
> increase in brain size= problem of fitting through
what are two broad categorises of adaptions to the obstetrical dilemma
- maternal
2. neonate
describe maternal adaptions to the obstetrical dilemma
increase neonate cranium> elective pressure on
- dimorphism of pelvis (size of female opening)
- softening of pubic symphyses at end of pregnancy
describe neonate adaptions to the obstetrical dilemma
bones of cranium not fused
> able to slip + allow through
> space for rapid post natal brain development
