Human Evolution 03 Flashcards
Modern Human vs primitive features
• short humerus | long forearm, stable elbow
• lumbar lordosis | funnel shaped thorax, small vertebrae
• wide sacrum | small hip joint
• long femoral neck, valgus knee | short femur
• adducted hallux | long curved toes
Humans vs. Australopitecines
still used upper limb for climbing, strong lower limb for bipedal locomotion
How did Lucy probably die?
Many complex fractures indicate fall from high hight => tree => climbing
What do Laetoli footprints suggest?
Footprint deeper on outside
Rotation in hip joints rather than in lumbar region
Footprint size => estimate stature of them according to Lucy’s body/foot size => slightly larger
Male and female or diff. species? not clear, but large stature of hominins at beginning
What has been discovered in the Olduvai gorge?
• Stone tools
• evidence of early homo => skull of paranthropus boisei
But might not have been toolmaker
• Homo habilis (handy man)
Homo habilis
1.8 Ma
skull suggests larger brain size
Mandible with smaller teeth, compressed and elongated => human like
Foot suggests bipedalism
Strong finger bones (stone tools, climbing?)
Longer humerus than Lucy, otherwise similar morphology
Early homo from Ethiopia
2.8 Ma
narrow, elongated molar teeth, third molar smaller than second
shape of mandible is Australopithecine like
Stone tools before homo?
Cut marks => butchering
Stone tools => 3.3 Ma suggests Australopithecines made them
Brain size
Humans defined by large brain size
Homo habilis smaller => similar to Australopithecines
Threshold is outdated
Was Lucy more human-like than Homo habilis?
Limb proportions (humerus length & circumference) of Lucy human-like, Homo habilis great-ape-like (but gorillas and chimps and too small a sample size (few small))
If accounted for these: both fall into humans, lower limb of homo habilis could have been more human like
So NO => but we need more fossils
Homo rudolfensis
2 Ma
Large brain size (human)
Flat face (paranthropus)
Different morph/species from h. habilis?
teeth/mandible suggest diff. species
Which 4 species of human-like great apes lived at the same time (ca. 1.9 Ma)
• Paranthropus boisei
• Homo rudolfensis
• Homo habilis
• Homo erectus
Homo erectus
flat skull cap
small brain size
fully upright
very human like femur
no chin => receding mental symphysis
marked superorbital ridge/torus
sulcus behind superorbital ridge
occipital torus, runs to ear
torus on saggital region
=> flat and thik/robust skull
engarvings on shells => symbolic behavior
teeth from china (dragon teeth) => sinanthropus => fossils lost in WWII
very diverse geographic distribution
few postcranial fossils
KNM-WT 15000
~ 1.5 Ma
skeleton of boy
ca. 1.40 m => adults could have diff. stature (1.80 or 1.60)
flat, asymmetric ribs => but maybe just juvenile, so normal, also new rip fragments found => no longer asymmetric
=> scolliosis => no scolliosis
vertebrae => disc herneation
asymmetric pelvis => reconstruction: not asymmetric, more primitive, broader
rare genetic disorder?
When did body stature of modern himans evolve? What does it suggest for Homo erectus
Quite late, diff from H. erectus
=> modern humans shorter legs
suggests H. erectus were endurance runners? & follow migrating animals out of Africa