The Evolution of Homo sapiens Chapter 15

Homo sapiens H. sapiens All contemporary hominin populations Delicate Crania Vertical Foreheads Pyramidal mastoid process Point of attachment for several muscles Canine fossa Depression below the orbital that allows for greater muscle control in non-verbal communication

Variation and distribution Homo sapiens

Questions About the Origin and Dispersal of Modern Humans When (approximately) did modern humans first appear? Where did the transition take place? What was the pace of evolutionary change? How quickly did the transition occur? How did the dispersal of modern humans to other areas of the Old World (outside of their area of origin) take place?

Homo sapiens Most paleoanthropologists agree that fossil forms dating back as far as 100,000 ya should be included in the same fully modern group as modern humans Models of Human Origins: Multiregional Evolution Two “Out-of-Africa” Models

Multiregional Evolution Populations, connected by gene flow, in Europe, Asia, and Africa continued evolutionary development from archaic H. sapiens to anatomically modern humans Associated with paleoanthropologist Milford Wolpoff of the University of Michigan

Complete Replacement Model Proposes anatomically modern populations arose in Africa in the last 200,000 years They migrated from Africa, completely replacing premodern populations in Europe and Asia Does not account for the transition from premodern forms to H. sapiens anywhere except Africa Developed by British paleoanthropologists Christopher Stringer and Peter Andrews

Partial Replacement Model Various perspectives suggest that modern humans originated in Africa and then, when their population increased, expanded out of Africa into other areas of the Old World This model claims that interbreeding occurred between emigrating Africans and resident premodern populations

The Origins of Modern Humans

Time Line of Modern Homo Sapiens Discoveries: What do the Data Say?

Early Homo sapiens Discoveries From Africa and the Near East Dates Site Hominind Evolutionary Significance 195,000 ya Omo Ethiopia H. sapiens Oldest modern human; two crania found, one more modern looking than the other 154,000 - 160,000 ya Herto Ethiopia idaltu Well-preserved cranium; best-preserved early modern human found anywhere

Early Homo sapiens Discoveries From Africa and the Near East Dates Site Hominin Evolutionary Significance 115,000 ya Skhul Israel H. sapiens sapiens Minimum of 10 individuals; earliest modern humans known outside of Africa 110,000 ya Qafzeh Israel Large sample; modern, but some individuals fairly robust; early date

Herto Cranium Herto cranium from Ethiopia, dated 160,000–154,000 ya. Adult Mosaic of modern and premodern traits Very large and long cranial vault 1450 cm3 Large, arching browridge and projecting occipital protuberance H. sapiens idaltu “idaltu” is the Afar word for “elder”

Specimens From Israel Skhül 5. (a) Qafzeh 6 (b) Modern traits 130,000-100,000 ya Qafzeh 6 (b) 120,000-92,000 ya Modern traits Vault height Forehead Lack of prognathism Contemporary with Neandertals in Region

Key Early Modern Homo sapiens from Europe and Asia Dates Site Hominin Evolutionary Significance 40,000 ya Tianyuan Cave Beijing, China H. sapiens sapiens Partial skull and a few postcranial bones; oldest modern human find from China 40,000-45,000 ya Niah Cave Borneo, Indonesia Partial skull; oldest modern human find from Asia

Key Early Modern Homo sapiens from Europe and Asia Dates Site Hominin Evolutionary Significance 30,000 ya Cro-Magnon France H. sapiens sapiens Most famous early modern human find; earliest evidence of modern humans in France 24,500 ya Abrigo do Lagar Velho Portugal Child’s skeleton; possible hybrid of Neandertal and modern human, it is controversial

Cro-Magnon I Cro-Magnon I (France) European Upper Paleolithic Approx 40,000 ya Modern traits are clear Robustly built and powerful Cranial capacity around 1,600 cc

Neandertal/H. sapiens Admixture Abrigo do Lagar Velho “hybrid” child Recent Genetic comparisons of Neandertal DNA and contemporary humans Populations outside of Africa typically have more Neandertal DNA Refutes hypotheses of complete replacement of the Neanderthals by early modern humans

Comparing Skulls Homo Sapiens Neandertals The next few slides could contain images of Neandertal skulls paired with the ones profiled in Chapter 11. The goal could be to get students to identify those traits that are criteria for identification as H. sapiens. Not only would this reinforce taxonomic distinctions, but would also illustrate the continuous nature of morphological variation and that lines between species, especially fossil ones are blurry.

Homo floresiensis Indonesian island of Flores in 2004 Taxonomy History Originally dated to 95,000 to 13,000 years ago New estimates until 50,000 years ago Archaic Homo survived well into the lifespan of AMH Taxonomy Skull slightly smaller than chimpanzees Stood 3 ft with big feet, stubby big toe Probably could not run History H. erectus arrives in Flores 840,000 years ago Controlled fire and used stone tools more sophisticated than H. erectus Influenced by same evolutionary forces that led to smaller species of elephant on the island

Australia and the New World 50,000 ya modern humans inhabited Sahul Area including New Guinea and Australia Kow Swamp 14,000-9,000 ya Fossils with archaic features The Americas Probably populated by Asian hunters following prey across the Bering Strait Firmest dates in the New World are 13,500 ya Dates of up to 27,900 ya have been suggested

Upper Paleolithic Technology 50,000 to 10,000 ya Upper Paleolithic is often defined by: High frequency of stone blades Bone, antler, ivory, and horn tools were also made A variety of artistic methods and styles including Paintings Engraving Sculpture

Cave Art Dated back to 36,000 years ago More than a hundred sites, mostly southern France Lascaux Limestone walls have absorbed the paintings Paintings of prey: mammoths, wild cattle, deer, reindeer, horse Largest animal is 18 feet long Perhaps pre-hunt ritual Some portrayed with spears, others pregnant or copulating Animal fertility ritual? Hunt history?

The Rise of Civilization Increase in population Sumer Earliest civilization developed in the Middle East The Bronze Age Metallurgy was refined Civilizations arose in other parts of the Old World and independently in parts of the New World