Human Evolution Darwin to the Paleolithic

Today’s Objectives

How do humans differ from early primates?

Skeleton, organs, culture

Why was Homo erectus so successful as an early hominid?

What happened to Neanderthals?

Be able to briefly trace the cultural development of:

tools, fire, clothing, shelter, art

What is so important about the Upper Paleolithic?

Theories of EvolutionOrigin Myths/Cosmologies

Greek – PrometheusGenesis

**Above both Western Examples

Left: Prometheus and AthenaTop: God and Adam

Theory of Evolution

Darwin and Wallace, 1850s

Evolution theory holds that existing species of plants and animals have emerged over millions of years from simple organisms.Darwin, On the origin of species, 1859Influenced by the principle of uniformitarianism

Charles Darwin

The Theory of Evolution

Darwin’s principle of natural selection“Natural selection is the gradual process by which nature selects the forms most fit to survive and reproduce in a given environment.”For natural selection to work on a given population, there must be variety within that population and competition for strategic resources.The concept of natural selection argues that organisms which have a better fit within their environmental niche will reproduce more frequently than those organisms that fit less well.

Theories of Evolution

Random genetic drift is the loss of alleles from a population's gene pool through chance.

Mutation introduces genetic variation into a breeding population.

Gene flow occurs through interbreeding: the transmission of genetic material from one population to another. Gene flow decreases differences and inhibits speciation, the formation of new species.

Theories of Evolution - Corollaries

Mendel’s principle of inheritance, 1856

The science of genetics explains the origin of the variety upon which natural selection operates.

By experimenting with successive generations of pea plants, Mendel came to the conclusion that heredity is determined by discrete particles, the effects of which may disappear in one generation, and reappear in the next.

Other Theories

Creationism accounts for biological diversity by referring to the divine act of Creation as described in Genesis.

Catastrophism is a modified version of Creationism, which accounts for the fossil record by positing divinely authored worldwide disasters that wiped out the creatures represented in the fossil record, who were then supplanted by newer, created species.

Intelligent Design states that modern physics and cosmology have uncovered evidence for intelligence in the structure of the universe and this intelligence seems to act with us in mind and that the universe as a whole shows evidence of design.

Early Primates - TraitsCommon physical primate traits:

Dense hair or fur covering

Warm-blooded

Live young

Suckle

Infant dependence

Common social primate traits:

Social life

Play

Observation and imitation

Pecking order

Evolution of BipedalismAnatomical Changes

Neck (1), chest (2), lower back (3), hips and

pelvis (4), thighs (5), knees (6), feet (7)

Theories

Tool use and bipedalism (Darwin/Washburn)

Energy efficiency and bipedalism

(Isbell/Young)

Radiator theory (Falk)

Body temperature and bipedalism

(Wheeler)

Habitat variability and bipedalism (Potts)

Reproduction and bipedalism (Lovejoy)

Canine reduction and bipedalism (Jolly)

Pre-hominid EvolutionArdipithecus ramidus 4.4 - ? Mya (million years ago)

A. anamensis 4.2 - 3.9

A. afarensis 4.2 - 2.5

A. bahrelghazali 3.5 - 3.0

A. africanus 3.5 - 2.5

P. aethiopicus 2.7 - 2.3

A. garhi 2.5 - ?

P. boisei 2.3 - 1.3

P. robustus 2.0 - 1.0

BipedalismToolsLanguage Reconstruction of Australopithecine

Hominid Evolution

Homo habilis (2.0 – 1.6mya)

H. rudolfensis (2.4-

1.6mya)

H. erectus (1.9-27kyBP)

H. heidelbergensis (800-

100kyBP)

H. neanderthalensis (300-30kyBP)

H. sapiens (130kyBP –

present)

Hominid Evolution

Major Homo advances:Brain sizeBetter bipedalismHuntingFire (H. erectus)Tools

Oldowon (H. habilis)Acheulean (H. erectus)Mousterian (H. heidelbergensis)Solutrean (H. sapiens)

Built shelters (H. heidelbergensis)Clothing (H. neandertalensis)Language (Neanderhtals?)

Homo Habilis

612 cc brain

2.3 - 1.6 mya

first toolmaker

prognathic face, brow ridge

probable meat-eater

possibly arboreal

discovered in 1960 by Leakeys

no speechArtist’s representation of a Homo habilis band as it might have existed two million years ago.

H. Habilis v. H. erectus

Finds in east Africa indicate that Homo habilis was not very different from the australopithecines in terms of body size and shape.

The earliest Homo erectus remains indicate rapid biological change.

The fossil record for the transition from H. habilis to H. erectus supports the punctuated equilibrium model of evolution.H. erectus was considerably taller and had a larger brain than H. habilis.

Homo erectus

1891 - Eugene Dubois discovers H. erectus in JavaDubois calls it Pithecanthropus erectus initially, also dubbed “Java Man”finds in China called Sinanthropusdates from 1.9 mya to 27,000 years B.P.994 cc brain size (compare to 612 for H. habilis)Acheulean tool industry

Photograph of Nariokotome boy, an early Homo erectus found near Lake Turkana, Kenya.

Homo erectus – 1.9mya to 27k yBP

Why was H. erectus so successful?Less sexual dimorphism = possible pair bonds, marriageLess hair on body = wearing of furs, other clothingWearing of furs = ability to live further northQuick adaptation to environment without physical changesCulture is main reason H. erectus was so successful

organization for huntingability to protect against predatorscontrol of fire?possible campsitestools (Acheulean industry)

Distribution of H. erectus

Homo neanderthalansisdiscovered in the Neander Valley (Tal) near Dusseldorf, 1856

massive brain--about 1,400cc on average

large torso, short limbs, broad nasal passages

later remains show decrease in robustness of the front teeth and face, suggesting use of tools replaced teeth

retained occipital torus, some mid-facial prognathism

The skull of the classic Neandertal found in 1908 at La Chapelle-aux-Saints.

Neanderthal Culture

Homesites – In caves, also

in the open (near rivers,

framed with wood and

covered with skins)

Burial – Is there evidence of

purposeful burial and ritual?

Language – Could

Neandertals talk or not?

Tools – Mousterian tradition

Top: Reconstruction of Neandertal burial from Shanidar caveBottom: Mousterian tools

What happened to Neanderthals?

H. neanderthalensis coexisted with H. sapiens for

at least 20,000 years, perhaps as long as 60,000

years

What happened?

Neandertals interbred with H. sapiens

Neandertals were killed off by H. sapiens

H. sapiens drove Neandertals into extinction by

competition

Archaic H. sapiens Culture

Cave paintingsMostly animals on bare wallsSubjects were animals favored for their meat and skinsHuman figures were rarely drawn due to taboos and fears that it would somehow harm others

rchaic H. sapiens Culture

Upper Palaeolithic –

Hotbed of Culture40 – 10k yBP

Shelters

15,000 yBP Ukraine

Some made with mammoth bones

Wood, leather working; carpentry

Tools

From cores to blades

Specialization

Composite tools

Bow and arrow

Domestication of dogs

Gathering rather than hunting became the mainstay of human economies.

Top: Straw Hut

Left: Mammoth bone hut

Bottom: Tool progression

Homo sapiens

Archaic – 100,000 to 35,000 years BP

Sometimes called Homo sapiens and Homo sapiens neanderthalensis

Modern – 35,000 years BP to present

Anatomically modern

Sometimes called Homo sapiens sapiens

Cro-Magnon Man

Cro-Magnon humans35,000 years B.P. in western Europe to 17,000 years B.P.1,600 cc cranial capacityName comes from a hotel in FranceNot a different species, just old Homo sapiens from Europe

Artist’s reconstruction of a Cro-Magnon man

Archaic H. sapiens Culture

ArtTraces of art found in beads, carvings, and paintingsCave paintings in Spain and southern France showed a marked degree of skill

Female figurines27,000 to 22,000 years B.P.Called “venuses,” these figurines depicted women with large breasts and broad hips• Perhaps it was an example of an

ideal type, or perhaps an expression of a desire for fertility

Archaic H. sapiens Culture

Cave paintingsMostly animals on bare wallsSubjects were animals favored for their meat and skinsHuman figures were rarely drawn due to taboos and fears that it would somehow harm others

Upper Palaeolithic Hotbed of Culture40 – 10k yBP

Shelters15,000 yBP Ukraine

Some made with mammoth bones

Wood, leather working; carpentry

ToolsFrom cores to blades

Specialization

Composite tools

Bow and arrow

Domestication of dogs

Gathering rather than hunting became the mainstay of human economies.

Top: Straw Hut

Left: Mammoth bone hut

Bottom: Tool progression

Modern Homo sapiensRegional-Continuity Model (Milford Wolpoff, UMich)

Humans evolved more or less simultaneously across the entire Old World from several ancestral populations.

Rapid-Replacement Model (Chris Stringer, NHM London)

Humans evolved only once--in Africa from H. heidelbergensis ancestors--and then migrated throughout the Old World, replacing their archaic predecessors.

Also called the “Out of Africa” and “Killer Ape” hypothesis.

Social Organization

Hunter-gatherer analogySmall group, low population density, nomadism, kinship groups

MigrationNorth America was the last colonized by hominids.Beringia (land bridge) between Russia and AlaskaAsian origin of Native Americans30,000 to 12,000 years B.P. was first migration