Hominid Fossil Record

Geology 230: Fossils and Evolution

Human ancestors

A.=Australopithicus

Collecting Hominid fossils

in East Africa

Using Stratigraphy and Radiometric Dating to

date hominid fossils

A Hominid Jawbone in Ethiopia

Hominid Record, 2002

Sahelanthropus

tchadensis, 6.5 MY old

Sahelanthropus

tchadensis,

6.5 MY old

Gorilla – female on left,

male on right; note the

sexual dimorphism

Orrorin tugenensis – the sum

total of specimens

Ardipithecus

ramidus, 2009

Ardipithecus ramidus, 2009

Hand Foot

Digitally

Reconstructed

Skull from

Broken Pieces

using Computed

Tomography

Ardipithecus

ramidus

Australopithecus anamensis

The Australopithecines

• Ardipithecus: oldest definite bipedal ancestor, over 4 M.Y. old

• Australopithecus: the gracile australopithecines

• Paranthropus: the robust australopithecines

Fossil Species

• Ardipithecus ramidus: 4.4 MY, teeth, jaws and bone fragments suggest it is a hominid, not a pongid.

• Australopithecus afarensis: 3.8-3.0 MY based on good fossils. Clearly a bipedal animal based on bones and fossil footprints.

Bipedal Footprints of Australopithecus

in Lithified Volcanic Ash 4 MY old from

Tanzania. Found by Mary Leakey.

Australopithecus

couple making

footprints in

volcanic ash

Jawbones of Australopithecus afarensis

Fossil remains

of “Lucy”, the

most complete

specimen of

Australopithecus

afarensis.

An adult skull, A. afarensis

Pelvis of Australopithecus afarensis

Reconstruction of

Australopithecus

afarensis

Face-to-face

with

A. afarensis

A troop of

A. afarensis

feeding on

tubers in the

forest.

A. afarensis

family unit

crossing the

savannah.

Fossil Species

• Australopithecus africanus: 2.8-2.5 MY

• Robust australopithecines:

Paranthropus aethiopicus: 2.6-2.2 MY

P. robustus: 2.0-1.2 MY

P. boisei: 2.6-1.0 MY

The Taung Child, A. africanus

Skull of Paranthropus boisei

Paranthropus aethiopicus

Paranthropus aethiopicus

Justus Erus

found the

fossil

Kenyanthropus

platyops, 3.5 MY old

from Kenya

Kenyanthropus rudolfensis or

Homo rudolfensis?

Fossil Species

• Homo habilis: 2.5-1.6 MY

• H. erectus: 1.8 MY- 25,000 yrs?

Java man

Peking man

• H. sapiens: archaic vs. modern

Skull of

Homo

habilis

H. rudolfensis, H.

habilis, and P.

boisei. Hominids

in East Africa

around 2 MY

ago.

Phylogeny

2000

*

*

*

** Poorly known

Phylogeny

2007

Prothero, 2007

* *

*

*

*

**

* Poorly known

*

2010

Skull of Homo erectus from China

Skeleton of

Homo erectus,

Nariokotome

boy from Kenya

H. erectus skull of Nariokotome boy

The face of

Homo

erectus

Homo erectus from

Indonesia, Java Man

Homo erectus using fire to

sharpen spears

Homo sapiens

• Archaic H. sapiens or unique species?

H. antecessor: 800,000 years old

H. heidelbergensis: 500,000 years old

H. neandertalensis: 200,000-32,000 years old

Homo antecessor from Spain,

800,000 years old

Homo heidelbergensis,

500,000 years BP

Neanderthal

skull, Spain

Fleshing out a Neanderthal skull

Neanderthal burial, 50,000 yrs. BP

Neanderthal skeleton, Germany

Homo neadertalensis leading a

nomadic existence

Neandertals were big-game hunters.

Neandertal night life around the fire.

A more modern view of Neandertals

with naked skin like ours?

Reconstruction of Neanderthal child from

Gibraltar, Spain, 30,000 years B.P.

Homo sapiens

• modern H. sapiens

East Africa: 195,000 years ago

Middle East: 90,000 years ago

Australia: 50,000 years ago

Europe: 32,000 years ago

Americas: 20,000 years ago

Homo

sapiens,

Israel, 90,000

yrs BP

FYI: Abraham lived

only 4,000 yrs BP

Cro-Magnon man from France,

30,000 years old

Homo floresiensis, a hobbit-size

human from Flores Island, Indonesia,

18,000 BP

Modern human

Homo sapiens

(Cro-Magnon

people) drew the

cave art in France

and Spain about

17,000 years ago.

Lascaux, France, cave art

Life in the late Stone Age, which ended at

different times on different continents.

The invention of farming, plus domestication of

animals, started civilization.

Evolution of Modern Humans

Two Theories:

• Out of Africa: all modern humans descended from a single population. Racial differences have very recent origins.

• Multiregional Theory: modern humans evolved from local populations of H. erectus at several places in the Old World. Accounts for the racial differences in modern humans.

Out of Africa Hypothesis

Multiregional

Hypothesisvs

DNA studies

show the

common

ancestor of all

humans lived in

Africa about

170,000 yrs ago

Tree

Diagram

of Genetic

Similarity

How far back in

time did the

modern “races”

diverge from a

common

ancestor?

Maybe 50-100 Ka