The Origin and Dispersal of Modern Humans Chapter 11 The Origin and Dispersal of Modern Humans

Chapter Outline Approaches to Understanding Modern Human Origins The Earliest Discoveries of Modern Humans Something New and Different Technology and Art in the Upper Paleolithic Summary of Upper Paleolithic Culture

Homo sapiens sapiens All contemporary populations are placed in the subspecies Homo sapiens sapiens. Most paleoanthropologists agree that several fossil forms, dating as far back as 100,000 y.a., should be included in the same subspecies. Recently discovered fossils from Africa are clearly H. sapiens, but show minor differences from living people and could be described as “near-modern.”

Questions About the Origin and Dispersal of H. sapiens sapiens When did H. sapiens sapiens first appear? Where did the transition take place? In one region or several? What was the pace of evolutionary change? How fast did the transition occur? How did the dispersal of H. sapiens sapiens to other areas of the Old World take place?

Theories of Human Origins Complete Replacement Model Regional Continuity Model Partial Replacement Model

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

Partial Replacement Model Proposed by Günter Bräuer of the University of Hamburg. Postulates the earliest dates for African modern Homo sapiens at over 100,000 y.a.

Partial Replacement Model Initial dispersal of H. sapiens sapiens from South Africa was influenced by environmental conditions. Moving into Eurasia, modern humans hybridized with resident groups, eventually replacing them. The disappearance of archaic humans was due to hybridization and replacement.

Regional Continuity Model (Multiregional Evolution) Associated with paleoanthropologist Milford Wolpoff of the University of Michigan. Populations in Europe, Asia, and Africa continued evolutionary development from archaic H. sapiens to anatomically modern humans.

The Regional Continuity Model (Multiregional Evolution) Question: How did modern humans evolve in different continents and end up so physically and genetically similar? Explanation: Due to gene flow between archaic populations, modern humans are not a separate species. Earlier modern H. sapiens did not originate exclusively in Africa.

Early Homo sapiens Discoveries From Africa and the Near East Site Dates (y.a.) Human Remains Comments Qafzeh (Israel) 110,000 20 individuals (minimum) Large sample; variability in expression of modern traits Skhu-l (Israel) 115,000 10 individuals (minimum) Earliest evidence of modern H. sapiens outside of Africa

Early Homo sapiens Discoveries From Africa and the Near East Site Dates (y.a.) Human Remains Comments Omo-Kibish (Ethiopia) 120,000–80,000? Cranium and postcranial remains Second individual shows fewer modern traits Klasies River Mouth (South Africa) 120,000? Several individuals; fragmentary Perhaps earliest modern H. sapiens in Africa

Early Modern Homo sapiens Discoveries - Europe, Asia, Australia Site Dates (y.a.) Human Remains Comments Abrigo do Lagar 24,500 4 y.o. child’s skeleton Shows mixture of traits Velho (Portugal) Interpreted as evidence of hybridization Cro-Magnon (France) 30,000 8 individuals Famous site of early modern H. sapiens; variability in expression of modern traits

Early Modern Homo sapiens Discoveries - Europe, Asia, Australia Site Dates (y.a.) Human Remains Comments Ordos (Mongolia, China) 50,000 1 individual Perhaps earliest evidence of H. sapiens in Asia Kow Swamp (Australia) 14,000-9,000 More than 40 individuals (all ages) Very robust individuals Lake Mungo (Australia) 60,000- 30,000 3 individuals, one cremation Date is controversial; recent extraction and analysis of DNA

Techniques for Dating Middle and Upper Pleistocene Sites Physical Basis Examples of Use Uranium series Radioactive decay of short-lived uranium isotopes Date limestone formations; estimate age of Jinniushan site in China and Ngandong site in Java Thermoluminescence (TL) Accumulation of electrons in certain crystals released during heating Date ancient flint tools; provide key dates for the Qafzeh site Electron spin resonance (ESR) Measurement of trapped electrons Date dental enamel; corroborate dating various sites in Israel, Java, South Africa, and Australia

The New World Ancestors of Native Americans reached the New World through migration over the Bering Land Bridge over many millennia. Debates continue, but at present, the only direct evidence of hominids in the New World date to about 12,000 y.a.

Anatomically modern Homo sapiens and Homo floresiensis

The Upper Paleolithic Cultural period began in western Europe approximately 40,000 years ago. Industries based on tool technologies: Chatelperronian Aurignacian Gravettian Solutrean Magdalenian

Upper Paleolithic Tools (a) Burin. A very common Upper Paleolithic tool. (b) Solutrean blade. This is the best-known work of the Solutrean tradition. Solutrean stonework is considered the most highly developed of any Upper Paleolithic industry.

Cultural Periods of the European Upper Paleolithic Upper Paleolithic (beginnings) Cultural Periods 17,000 21,000 27,000 40,000 Magdalenian Solutrean Gravettian Aurignacian Chatelperronian Middle Paleolithic Mousterian

Cave Art Majority from southwestern France and northern Spain. Grotte Chauvet Dating has placed the cave painting during the Aurignacian period more than 30,000 y.a. Images include stylized dots, human handprints and animal representations. Among traces are dozens of footprints on the cave floor produced by bears and humans.

Africa Rock art is found in southern Africa dating to between 28,000 and 19,000 y.a. Personal adornment dates back to 38,000 y.a. in the form of beads made from ostrich shells. Excavations in the Katanda area show remarkable bone craftsmanship. Intricate bone tools resembling harpoons were made from the ribs of large mammals.

Quick Quiz

1. Which of the following is NOT one of the hypotheses explaining the origins and dispersal of anatomically modern humans? the partial replacement model the regional continuity model the regional replacement model the complete replacement model

Answer: c The regional replacement model is NOT one of the hypotheses explaining the origins and dispersal of anatomically modern humans.

2. Scientists are fairly clear on when anatomically modern Homo sapiens first appeared. True False

Answer: False Scientists are not fairly clear on when anatomically modern Homo sapiens first appeared.

3. The _________________ holds that anatomically modern populations arose in Africa within the last 200,000 years, migrated out and replaced populations in Europe and Asia. They did not interbreed because they were a separate species.

Answer: Complete Replacement Model 3. The Complete Replacement Model holds that anatomically modern populations arose in Africa within the last 200,000 years, migrated out and replaced populations in Europe and Asia. They did not interbreed because they were a separate species.

4. The model also known as "Recent African Evolution" is based on the origin of modern humans in Africa and their interbreeding with local African populations. in Africa and their replacement of local populations in Europe and Asia. in China and their relatively recent evolution in Africa. simultaneously in Africa and China.

Answer: b The model also known as "Recent African Evolution" is based on the origin of modern humans in Africa and their replacement of local populations in Europe and Asia.