Hominid Evolution

When? Where? u Evolution Timeline Evolution Timeline

Trends u Bipedalism l African genesis u Savannas? u Environmental variability? l factors favoring bipedalism l modifications for bipedalism l costs of bipedalism

Hominid Trends (cont.) u Expansion of Brain l early hominids = small brains l factors contributing to expansion u Other Trends l reduction of face / teeth / jaws l wider female pelvis l longer infant dependency l division of labor

Australopithecines u Fossil Finds l plentiful sites (Africa) l indicate bipedalism

Australopithecines (cont.) u Adaptations of Australopithecines l dentition l habitation l sexual dimorphism l brain size increasing l habitual bipedalism l use of tools

Homo habilis u Introduction l appeared 2.5 mya l stone tools u traits l larger brain size l elaboration of culture l elaboration of tools l dentition

Homo habilis (cont.) u Cultural Characteristics of Homo habilis l Oldowan pebble tools u unifacial & bifacial u percussion flaking l increased consumption of meat u exploited wide range of animals l mobile populations

Homo erectus u Introduction l widely distributed species u Early Discoveries l “Java Man” u Eugene Dubois – 1891 u Thought to have Asian origin l Other finds u 1950’s – Africa v Indicated earliest presence was African continent

Homo erectus (cont.) u Physical Traits of Homo erectus l increasing brain size l thick skull l face reducing l molars reduced

Homo erectus (cont.) u Acheulian Tool Tradition l St. Acheul, France - first discovery l comparison to Oldowan tools u more elaborate l tools for butchering

Homo erectus (cont.) u Control of Fire l Zhoukoudian Cave, China l Uses of fire u Campsites l near water sites l caves and open areas l base camps? specialized camps? l Terra Amata - near Nice, France

Transition from Homo erectus u areas of agreement u areas of disagreement u fossils with mixed traits l Africa / Europe / Asia u fossils < 200,000 years old l definitely Homo sapiens

Two Origin Theories u Single-origin theory (hatrack) l modern humans evolved in one place l spread rapidly to other areas l superseded Neanderthals l DNA evidence l “Eve” hypothesis u Out-of-Africa

Two Origin Theories (cont.) u Multiregional theory (candelabra) l modern humans evolved in various parts of the Old World u evolved from widely dispersed H. erectus populations u resulted in wide varieties of humans we observe today

Two Origin Theories (cont.) u Multiregional theory (cont.) l Neanderthals were “transitional” form