Sedimentology and Palaeontology Lecture 13: Early Human Evolution Flashcards
Describe the origin of humanity
Homo Sapiens belong to a family
– This used to be one of history’s most guarded secrets
– We much preferred to set ourselves apart from the
rest of the animal kingdom…
- About 6 million years ago a female ape had two
daughters, one would become the ancestor of all
chimpanzees, the other is our own species
grandmother.
To be human is to be an animal belonging to the genus ‘Homo’
* Hominin = All our fossil ancestors
Define archaeological evidence/ archeaology
“Archaeology is the study of the
material remains and environmental
effects of human behaviour”
Describe the location of which the homo genus originated
The consistency of hominin finds, and
dates of there first appearance strongly
indicates that the vast majority of hominin
species evolved in East Africa and
dispersed outwards.
Specifically the East African, East valley rift system, where there is volcanic ash providing evidence of this.
Describe Orrorin tugenensis
Orrorin tugenensis
c.5.8 Ma ago
No skull ever found
First direct evidence
of bipedalism
Bone density
Lived in closed
woodland
Describe Australopithecus
Afarensis
Australopithecus
Afarensis
c.4.2 – 3.8 Ma ago
‘Lucy’
Capable walkers, long distance walking potentially established.
However would still climb very often.
small (similar size to a chimp)
* Still had long arms (for tree swinging), also small brain
Trace fossils found in volcanic ash (3.3Ma years)
Describe the movement/locomotive patterns of A. Afarensis
Deep impression of heel
– Large toe aligned with other toes
– Indicative of a type of slow-moving (“strolling”),
bipedal locomotion.
– Short stride
Describe evidence for use of stone tools
Stone Tools discovered in 2011 &
2012 - 3.3 Ma old
Predate Homo by 1 Ma years
Dikika, Ethiopia
* Cut marked bone.
* 3.39 Ma years old
Describe Homo Habillis
homo habilis
‘Handy Man’
c. 2.4-1.4 Ma ago
Thought to be the first makers of stone tools
Brain Size starts to increase
Describe Homo Erectus
Homo Erectus ‘Upright man’
The most durable human species ever,
was around for 2 million year
80% increase in brain size
Pelvis morphology change to allow the birth
of larger brained offspring
- Delayed grow period during childhood (can be
seen in teeth growth lines) - Long distance running
- Much more sophisticated stone tools
- Shoulders for throwing
- Most successful hominin species ever, surving
from 1.8 Ma to 200 ka ago
Fixed eye height
Describe the African rift system
One of the most extensive geological features on the Earths surface
- Runs N-S for 4,500 km
- Volcanism in the central and southern Rifts starts
between 15 to 8 Ma age - Current geomorphology established between 5.5 & 3.7 Ma ago.
- Fragmented landscape, almost all vegetation types present (rain forests to arid deserts).
– Thus the evolution of feet and legs that could cope with a range of terrains, which led to long distance running.
Formation of the rift ‘shoulders’, up
to 4 km high in places
What are the two types of plants?
C3 and C4 plants
Describe the differences between C3 and C4 plants
C3 is trees and shubrs
C4 is Grasses
Describe C3 plants/grasses
C3 Plants
- 250,000 species
- 75% of terrestrial
NPP - All plant forms
(trees etc.) - In all terrestrial
biomes - Fruits
- Nuts
- Grains
- Roots & Tubers
- Bark
- Leaves
Have been increasing in dominance
over the last 30 Ma
Describe C4 plants/trees and shrubs
C4 Plants
- 7500 species
- 23% of terrestrial NPP
- Largely herbaceous
- Requires warm
seasons - Water and N efficient
- Often pyrophytic
(likes fire) - Fibrous Leaves
- Small seeded grains
- Small, fibrous
rhizome
Describe the relationships between C3 & C4 plants and Hominins
C4 grasslands provided few plant resources for
hominins
However is does support high grazer productivity (for
those species who can digest these plants)
Grazing species may thus have been the exploitable
resource for early hominins
