Chapter 6 The First Humans © 2008 McGraw-Hill Higher Education. All right reserved. Window on...

Post on 11-Jan-2016

236 views 4 download

Transcript of Chapter 6 The First Humans © 2008 McGraw-Hill Higher Education. All right reserved. Window on...

Chapter 6The First Humans

© 2008 McGraw-Hill Higher Education. All right reserved.

Window on HumanityConrad Phillip Kottak

Third Edition

© 2008 McGraw-Hill Higher Education. All right reserved.

Human Family Tree

© 2008 McGraw-Hill Higher Education. All right reserved.

Overview

© 2008 McGraw-Hill Higher Education. All right reserved.

Evolution of HomoEarly HomoH. erectusArchaic H. sapiensNeandertalsAnatomically modern humans (AMH)

Settling the Americas

© 2008 McGraw-Hill Higher Education. All right reserved.

Early Homo

© 2008 McGraw-Hill Higher Education. All right reserved.

Distinctive early Homo trends – exhibited by H. habilis and later H. erectus:Major increases in brain size and complexityIncreasingly elaborate tool makingGreater reliance on hunting (in addition to

gathering)

H. rudolfenis and H. habilis

© 2008 McGraw-Hill Higher Education. All right reserved.

KNM-ER 1470 – skull found at Koobi Fora, KenyaLarge cranial capacity of the skull suggests it

belonged to Homo, but its molars are similar to those of hyperrobust australopithecines

Dating the skull is problematic – either 1.8 or 2.4 m.y.a.

KNM-ER 1813(H. Habilis)

What differences do you see in the skulls?

KNM-ER 1470(H. Rudolfensis)

Different theories about H. rudolfensis

© 2008 McGraw-Hill Higher Education. All right reserved.

KNM-ER 1470 represents a species (H. rudolfensis) separate from H. habilis

Rudolfensis was earlier than, ancestral to habilisRudolfensis and habilis lived at the same time

(from about 2.4 to 1.7 m.y.a.)Rudolfensis and habilis were simply male and

female members of the same species (H. habilis)

Punctuated Equilibrium Model

© 2008 McGraw-Hill Higher Education. All right reserved.

H. habilis was not very different from australopithecines in terms of body size and form (H. habilis was very simliar to Lucy)

Major and rapid change with the emergence of H. erectus (between 1.8 and 1.7-1.6 m.y.a.)Cranial capacity, body shape, and height of H.

erectus were comparable to those of modern humans

H. habilis to H. erectus transition may support a punctuated equilibrium model of the evolution of early hominins

© 2008 McGraw-Hill Higher Education. All right reserved.

© 2008 McGraw-Hill Higher Education. All right reserved.

Punctuated Equilibrium Model is the idea that evolution involves short periods of rapid change interspersed with longer periods of relative stability

Emergence of H. erectus

© 2008 McGraw-Hill Higher Education. All right reserved.

Major change in adaptive strategy – greater reliance on hunting

Rapid increase in the number and diversity of stone tools used for hunting and gatheringIncreasing reliance on cultural means of adaptation

Dietary changes eased the burden on the chewing apparatus – smaller dentition favored

Hunting of large prey encouraged the development of thicker skulls

Larger body size and cranial capacity (within range of modern humans)

Paleolithic tools

© 2008 McGraw-Hill Higher Education. All right reserved.

Three divisions of the Paleolithic (Old Stone Age):Lower Paleolithic

roughly associated with H. erectusMiddle Paleolithic

roughly associated with archaic H. sapiens, including the Neandertals

Upper Paleolithic roughly associated with early members of H.

sapiens sapiens (anatomically modern humans)

Acheulian Tools

© 2008 McGraw-Hill Higher Education. All right reserved.

Primary tool-making tradition of H. erectus during the Lower PaleolithicVarious tool types, including oval-shaped hand axesMore complex than earlier Oldowan pebble toolsAcheulian tradition illustrates trends in the evolution

of technology:Greater efficiencyManufacture of tools for specific tasks Increasingly complex technology

© 2008 McGraw-Hill Higher Education. All right reserved.

Hand Axes

Scrapers

Blades

Adaptive strategies of H. erectus

© 2008 McGraw-Hill Higher Education. All right reserved.

Interrelated biological and cultural changesImproved tools and “modern”

skeleton permitting long-distance walking and endurance – allowed H. erectus to increase its range and hunt more efficiently

Brain size was double that of australopithecines, within the low range of modern humans

Study of chewing muscles and molars indicate they were more dependent on hunting

© 2008 McGraw-Hill Higher Education. All right reserved.

Lived in Rock Shelters and CavesUse of Fire

Hearths found at various sitesFire allowed H. erectus to colonize a wider range of

climates, provided protection against predators, made cooking possible – less strain on chewing

Evolution and expansion of H. erectus

© 2008 McGraw-Hill Higher Education. All right reserved.

Important H. erectus sites:East and West Turkana, Kenya – 1.6 m.y.a.Dmanisi, former Soviet Republic of Georgia – 1.75 to

1.7 m.y.a.Indonesia (e.g., “Java man,” the first H. erectus find)

– at least 700,000 B.P. – perhaps 1.6 m.y.a.Zhoukoudian cave, China (e.g., “Peking man”) –

670,000 to 410,000 B.P.Kenya, Tanzania, Ethiopia, Eritrea, and South Africa

– 1 million to 500,000 B.P. at OlduvaiCeprano, Italy – 800,000 B.P.

Evolution and expansion of H. erectus

© 2008 McGraw-Hill Higher Education. All right reserved.

Evolution and expansion of H. erectusWidespread distribution of H. erectus fossils

and stone tools – indicates expansion out of tropics into subtropical and temperate zones of Asia and Europe

Archaic H. sapiens

© 2008 McGraw-Hill Higher Education. All right reserved.

300,000? to 28,000 B.P.Include the earliest members of our species

Neandertals (H. sapiens neanderthalensis) of Europe and the Middle East

Neandertal-like contemporaries in Africa and Asia (130,000 to 28,000 B.P.)

Brain size within the modern human range

Large jaw of Heidelberg man; transitional hominin, between H. Erectus and archaic H. Sapiens

© 2008 McGraw-Hill Higher Education. All right reserved.

Lived during the second and third glacials (ice ages)a warmer interglacial period – last part of the Middle

PleistoceneDistribution of fossils and tools in Europe, Africa,

and Asia reflects increased tolerance of environmental diversity

  Ice age conditions in the northern     hemisphere during the Pleistocene   (persistent glaciers with tundra and  cold forests at lower elevations  farther south)

Neandertals

© 2008 McGraw-Hill Higher Education. All right reserved.

Discovered in Western and Central Europe and the Middle East

Archaic human fossils with Neandertal-like features found in Africa and Asia

Neandertal AdaptationIn Western Europe were biologically and culturally

adapted to an extremely cold climate (Würm glacial)Made clothes and elaborate tools (Mousterian tradition)Hunted reindeer, mammoths, and woolly rhinosAnatomy (e.g., stocky build, massive nasal cavities)

reflected adaptation to cold climateMassive faces and heavy wear on front teeth – evidence

that teeth used for various purposes (e.g., chewing animal hides to make winter clothing)

© 2008 McGraw-Hill Higher Education. All right reserved.

Mousterian TraditionThe Mousterian Tradition was marked by

the progressive reduction in the use of large core tools, such as hand axes, as specialized flake tools became more common.

© 2008 McGraw-Hill Higher Education. All right reserved.

Mousterian tradition unifacial hide scraper (left) and spear point (right)  

(both were made from Levallois flakes)  

Mousterian tradition hand ax    

Oldowan tradition core tool

(chopper)

Neandertals

© 2008 McGraw-Hill Higher Education. All right reserved.

Became less robust through timeImproving tool technology may have

assumed some of the burdens formerly placed on the anatomy

Neandertals and modern humans

© 2008 McGraw-Hill Higher Education. All right reserved.

Debate over whether Neandertals were ancestral to modern Western Europeans

Current prevailing view: H. erectus split into two groupsOne group was ancestral to NeandertalsAnother group was ancestral to anatomically

modern humans (AMHs)AMHs evolved in Africa, Asia, Central Europe, or

the Middle East, then colonized Western Europe and displaced Neandertals around 50,000 B.P.

© 2008 McGraw-Hill Higher Education. All right reserved.

Neandertals and modern humans

© 2008 McGraw-Hill Higher Education. All right reserved.

Alternative view: Neandertals were ancestral to modern EuropeansEvidence: fossils from sites in Western and Central

Europe (e.g., Mladeč, l’Hortus, and Vindija) exhibit both Neandertal robustness and modern features

Fossils from Skhūl and Qafzeh in IsraelSuggest that archaic H. sapiens was evolving

directly into AMHs in the Middle East more than 50,000 years before Neandertals disappeared

Implication: Neandertals and AMHs overlapped in time, rather than being ancestor and descendant

Homo sapiens sapiens (AMHs)

© 2008 McGraw-Hill Higher Education. All right reserved.

Most scholars believe AMHs evolved from an archaic H.

sapiens ancestor in Africa deny that Neandertals were ancestral to

AMHs in Western Europe and the Middle East

According to this view, AMHs spread out from AfricaIn Western Europe, they replaced or

interbred with the NeandertalsColonized America

“Out of Africa” hypothesis

© 2008 McGraw-Hill Higher Education. All right reserved.

Study of mitochondrial DNA (mtDNA) lineagesEveryone alive today has mtDNA descended from a

woman (“Eve”) who lived in sub-Saharan Africa around 200,000 B.P.

Eve’s descendants left Africa no more than 135,000 B.P., displacing Neandertals in Western Europe and colonizing the rest of the world

Other evidence for African origin of AMHs:Three anatomically modern skulls dated to 154,000-

160,000 B.P. found in EthiopiaFossils and tools found at several South African sitesNeandertals coexisted with AMHs in the Middle East

for thousands of yearsChinese Skulls http://www.youtube.com/watch?

v=Y9zVEQCIiRs

© 2008 McGraw-Hill Higher Education. All right reserved.

© 2008 McGraw-Hill Higher Education. All right reserved.

Technological advances

© 2008 McGraw-Hill Higher Education. All right reserved.

Upper Paleolithic tool-making traditionsAssociated with early AMHsEmphasized blade toolsMore efficient than Mousterian techniquesSome composite and bone tools

Adapt to more environments

Click for video on Lascaux Prehistoric Cave Paintings

© 2008 McGraw-Hill Higher Education. All right reserved.

Glacial retreat

© 2008 McGraw-Hill Higher Education. All right reserved.

Retreat of ice sheet in northern Europe (17,000-12,000 B.P.)

Tundra and steppe vegetation replaced by shrubs, forests

Reindeer and other large game replaced by more solitary animals

Southwestern Europe – economies became less specializedHumans began to exploit a wider range of plant and

animal lifeBroad-spectrum revolution

Settling the Americas

© 2008 McGraw-Hill Higher Education. All right reserved.

Bering land bridge (Beringia) exposed during periods of glacial advance (15,000 years ago)

Gradual migration of big-game hunters from northeast Asia into North America

Southward migration via unglaciated corridors

Clovis points – used by Paleoindians to hunt large game in North America (12,000 to 11,000 B.P.)

Monte Verde site, ChileDated to 13,500 B.P.First migration of humans into the Americas may have occurred as early as 18,000 B.P.

© 2008 McGraw-Hill Higher Education. All right reserved.