Origins of Modern Humans, Continued

The Origins of Modern Humans Models used to explain the origin of modern humans: The “Out of Africa” Hypothesis The “Multiregional” Hypothesis

The Origins of Modern Humans Multiregional: Significant genetic contribution. Hypothesis that modern humans evolved throughout the Old World as a single species after the first dispersion of H. erectus out of Africa. Local populations maintained genetic integrity. This implies almost convergent evolution (wouldn’t be the same species).

The Origins of Modern Humans Out of Africa: No significant genetic contribution that local populations were replaced by modern humans. Bottleneck “Mitochondrial Eve” Oldest fossil evidence we have thus far for H. sapiens (Ethiopia 200,000 [not in Europe until 90,000 years ago]) Hypothesis that Humans evolved in Africa and then spread across the Old World.

The Origins of Modern Humans Which model fits best? Replacement is most clear (Out of Africa) mDNA and DNA indicates common genetic evidence. Continuity: Multiple cases of genetic continuity. OUT OF AFRICA

African Replacement Model Hypothesis: Modern humans evolved as a new species in Africa 200,000 years ago and then spread throughout the Old World, replacing preexisting populations.

Assimilation Model Hypothesis: Modern humans arose from Africa as a change within a species and then spread through gene flow to populations outside Africa. The gene pool of non-African populations was thus assimilated into an expanding population of modern humans outside of Africa.

Replacement vs. Assimilation 200,000 years ago our ancestors: All lived in Africa (replacement). Many lived in Africa, but not all (assimilation).

The Evidence Regional Continuity: the appearance of similar traits within a geographic region that remain over a long timeframe. Example: Shovel shaped incisors (incisors have a ridge of the outer margins). Found worldwide, but most frequently in both present and past populations in East Asia.

Consensus: African origins to modern humans. Argument of replacement vs assimilation still stands.

Cultural Behaviors Shelter: Caves and rock shelters Huts: constructed of wood, animal bone, animal hides. Mezhirich, Ukraine: 15,000 years old Shelters built almost entirely of mammoth bone. Mal’ta, southern Russia: 18,000 years old Used mammoth ribs and leg bones for the structural support of the hut.

Art in the Paleolithic Engravings have been found in Africa dating to 77,000 years ago. Most anthropologists consider 30,000 years ago to be a more definitive date for the beginnings of artistic expression. Art is found at 30,000 years ago in Europe, Africa and Australia. Cave paintings in Europe depicting large game animals are some of the best known examples of art during this time.

WHY ART???

Art in the Paleolithic Interpretations: Cultural symbolism. Communicating ideas/images. Sympathetic magic (capturing the image of an animal in order to improve the hunter’s chances of catching it in reality).

Art in the Paleolithic What do we actually know for sure about the meaning of Paleolithic art: NOTHING. We know humans were living in caves and rock shelters, and expressing something about animals, people, and objects.

Art in the Paleolithic Two basic forms: Types of Art: Portable art: (jewelry, figurines) Pictographs/Cave paintings Types of Art: Cave paintings. Engravings. Beads and pendants. Ceramic sculpture.

Art in the Paleolithic Lascaux Cave: in the Dordogne region of southwestern France. Estimated to be 17,000 years old. Contains nearly 2,000 figures. http://www.bradshawfoundation.com/lascaux/index.php

Art in the Paleolithic Cave of Hands: Argentina, ~13,000.

Geographic Expansion Humans became more able to adapt to new environments, and thus were able to expand the into new areas and their populations grew. Humans reached Australia between 60,000 to 46,000 years ago. Humans reached the Americas by roughly 15,000 years ago.

The Great Migration Humans reached N. America by at least 14,000 years ago. DNA evidence indicates affinity to Pacific Island populations. Bench mark site = Clovis site, 14,000 years ago.

Recent Biological Evolution in Homo sapiens Within the past 10,000 to 20,000 years we have continued to evolve and change in subtle ways. CC has declined (somewhat) Smaller teeth

Recent Cultural Evolution in Homo sapiens Major changes in human evolution within the past 10,000 to 15,000 years have been cultural. Agriculture Political Relations: kinship, bands, tribes chiefdoms, cities. Spirituality and/or Religion

Agriculture Began ~12,000 years ago (prior to this point humans had been exclusively hunters and gatherers). Lead to an increase in the availability of food. Population increase No single origin. Agriculture developed independently in many parts of the world.

Case study: Otzi the Iceman September 19th 1991 hikers in the glacial mountains between Austria and Italy found a body; turned out to be a naturally occurring mummy. Associated artifacts included: flint knife, axe, bow and arrows, furs and boots.

Case study: Otzi the Iceman C-14 dating confirmed the body was roughly 5,250 years old. Tattooed Arrow embedded in his shoulder; CT scans show that it had severed an artery, thus it was likely cause of death.