1. From Africa to the World
Origins of Genus Homo
From Africa to the World

2. Early Hominids Australopithicines splitting into 2 groups:
Robust – A. aethiopicus, A. boisei, A. robustus
Large teeth and jaws, some with pronounced sagittal crest.
Evolutionary dead end.
Gracile - A. anamensis, A. africanus, A. afarensis, A. garhi
Smaller stature, reduced teeth and jaw size, slighter larger brains.
Led to genus Homo.

5. Advent of Bipedalism
Required anatomical shifts occur during evolution of genus Australopithecus.
Changes include:
Position of foramen magnum
Orientation of leg bones
Pelvis changes

6. Why Bipedalism? Cons: Pros: more visible to predators.
Less biomechanically efficient.
Damage to 1 of 2 legs is lethal, 1 of 4 is not.
Pros:
Transport of items in hands
Better reconnaissance
Carry infants
Reduce heat stresses
Upright postures reduce heat loads by up to 60%

7. Why else Bipedalism? Brain and body temps coupled in hominids.
Brain can only grow as large as cooling allows.
Bipedalism reduces heat load on body, combined with better ‘plumbing; allows for increase in brain size.
Hair loss on body may allow for more effective sweating
Hair on head may allow for solar radiation shield.
Reflectance of hair is coded by same gene responsible for some putative IQ determinants. (Look into this Thorp).

9. Homo habilis ‘Handy man’ Bipedal as evidenced by foot bone alignment.
Either highly sexually dimorphic or 2 subspecies exist.
Brain size larger than Australopithecines but still smallish at ~ cc.
Brain cooling was markedly different from Australopithecines.
Possessed small openings in skull for veins to bring cooled blood from face and scalp into brain.
Teeth reduced in size from Australo.
Oldowan tool tradition.

10. Homo erectus origins Alternate naming conventions include:
Homo ergaster (African Homo erectus species, H. erectus reserved for Asian specimens).
Homo antecessor (possible Spanish subgroup)
Homo heidelbergensis (named for German fossil find, used by some to designate all European Homo erectus fossils from 500,000ya to appearance of Neanderthals.
Found outside of Africa
Result of single or multiple migrations.

12. Homo erectus characteristics
Larger stature, more heavily muscled.
Possible decreased sexual dimorphism.
Skull possesses mixed set of attributes:
Prominent browridges
Increased cranial capacity (see next slide)
Brain development is similar to that of modern humans, suggests increased cognitive ability and speech.

14. Homo neanderthalensis
Stocky muscular build
Large skull, large cranial capacity and occipital bun.
Midface projects outwards, large nasal area.
Sophisticated tools – Mousterian tradition
Evidence of tool kits containing specialized implements.
Allowed for improved clothing, shelter, hunting, etc.
Tool making skills used in artistic endeavors?
Ritual burial?