ANT100Y1 Lecture Notes - Lecture 5: Evolutionary Medicine, Koobi Fora, Antigenic Shift
October 22, 2015
Lecture #5: Human Evolution and Variation
Rise of the genus Homo
- Earliest evolved in Africa
- Most date 2.4 to 1.8 MYA
- First fossil member of taxon: Homo habilis which means “Handy Man”
o Primitive skeleton found in association with tools
o Many primates use stone tools not just humans
- Some researchers suggest that H. habilis is “junk taxon” and that there may be two or more species of Homo by
2.0 MYA
- Australopithecus found at same site and there hands possibly also showed tool use
- First species of Homo were neither particularly large nor well armed in terms of sharp teeth or claws
Species in the Genus Homo
Homo habilis “handyman”
- From sites in Tanzania, Kenya and Ethiopia (2.3-1.6 MYA)
- Species designation: brain size and association with stone tools
- Skeletal morphology similar to contemporaneous australopithecines
- First species of Homo or junk taxon?
- May represent 2 or more different species (H. rudolfensis and H. habilis)
Homo rudolfensis
- Koobi Fora, Kenya
- Originally considered H. habilis
- H. rudolfensis or H. habilis first representative of our genus
- Very controversial
- Very base part of tree is the one that is the most problematic
- Excited to find new fossils: Add to cladistics database to further refine ancestor relationships
Homo Erectus
- First species in genus Homo found outside Africa (Asia and Southeast Asia)
- First genus that left Africa
- 1.8 MYA-27 KYA
- Successful as it lasted so long
- Brain and body size changes in lineage
- Controlled use of fire and hunting
o Scavenging vs. hunting contentious
o Show ability to stalk, kill, dismember prey
- Early African specimens may be different species, Homo ergaster
o Where earliest representatives a unique species?
- Very strong
- Skull becoming more rounded, more of a forehead, massive browridge still exists, jaw tucked under face more
clearly, teeth more modern
Homo ergaster
- East and South Africa
- 1.8-1.3 MYA
- Distinguished by H. erectus by its thinner skull-bones and lack of an obcious supraorbital foramen
- Debate on H. erectus or H. ergaster as direct ancestor of modern humans
o Evolutionary dead end or where we come from?
- Giant brow ridges, flatter nose, powerful jaws, brain sizes larger than H. habilis or austra, differences aren’t
overtly different from humans
Homo ergaster: Turkana boy
- 7-16 years old
- ~ 1.6 m in height
o Didn’t realize they could be this tall
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- Brain size: 880 cc, likely 910 cc at adulthood (a modern human of comparable size would be expected to have a
brain size of about 1350 cc)
o Larger than any other predecessors in common ancestry
Homo heidelbergensis
- Europe and Africa
- 700-130 KYA
- Compared to H. erectus, H. heidelbergensis
o Decrease dentition
o Increased brain size
▪ Where earliest representatives a unique species?
o Increased body size
▪ Energetic cost is enormous
▪ Need more energy with bigger brain and bigger body size
Homo antecessor
- Cave in Spain
o Finding teeth is incredibly rare
- 1.2 MYA – 800 KYA
- Controversy surrounding species designation
- Type of specimen is juvenile
o Don’t know what they will look like as adults
o Changed when researchers went back and found many more ancestors
- 1st Hominin in Europe?
- A real taxon
- No fossil material of H. erectus in Europe
Homo neanderthalensis
- Europe and Middle East (300-35 KYA)
- Buried people in graves with offerings (ex// fragrant flowers)
o Very well preserved due to this
- Limb bones heavily marked by muscular attachments; thick walls of cortical bone and large joints
- Neanderthals extremely muscular, highly active, and athletic by modern human standards
o Faster, stronger, more powerful than us
o Look at the muscle attachment to the bones larger attachment=larger muscles
- Look similar to us
- Largest overall cranial capacity of any hominid
Homo naledi
- Discovered 2013 in South Africa
- Not dated as yet
- Body mass and stature = small-bodied human populations
- Endocranial volume similar to Australopithecus
- Skull shape similar to early Homo species
- So…skeleton combines primitive features in australopithecines with features known for hominids
- Local variant of Australopithecus
Homo florsiensis
- Flores island, Indonesia
- 95-13 KYA
o Very edge of historical archaeological record for humans
o People on island have stories about smaller people could have lived at the same time
- Small body size (ca. 1.06 m)
- Small brain size
- Mixture of primitive and derived features
- NOT aberrant individual; rather unique species
o Some people said aberrant individual with genetic variations to make small based off of pictures not
speciments
o Scientists didn’t agree
find more resources at oneclass.com
find more resources at oneclass.com
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Document Summary
First fossil member of taxon: homo habilis which means handy man : primitive skeleton found in association with tools, many primates use stone tools not just humans. Some researchers suggest that h. habilis is junk taxon and that there may be two or more species of homo by. Australopithecus found at same site and there hands possibly also showed tool use. First species of homo were neither particularly large nor well armed in terms of sharp teeth or claws. From sites in tanzania, kenya and ethiopia (2. 3-1. 6 mya) Species designation: brain size and association with stone tools. May represent 2 or more different species (h. rudolfensis and h. habilis) H. rudolfensis or h. habilis first representative of our genus. Very base part of tree is the one that is the most problematic. Excited to find new fossils: add to cladistics database to further refine ancestor relationships. First species in genus homo found outside africa (asia and southeast asia)
