What about Humans?
• Somewhere about 40
million years ago,
early primates—such
as the one pictured
here, began to evolve
to fit new
environmental niches.
Early Primates
•
•
•
•
Prosimians (65mya)
Monkeys (35mya)
Apes (23mya)
Hominids (5mya)
Australopithecus Afarensis
About 3.5 million years
ago the first primates
to exhibit bi-pedalism
appeared on Earth.
What advantages are
there to bi-pedalism?
Our backs and knees
work better as knuckle
walkers.
Climatic Change and Evolution
• One particularly
intriguing idea is that
Homo species evolved
as the climate changed
from Moist and
tropical to dry and
cooler.
• Why would this be
important?
Early Primates - Traits
• Common 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
Common Primate Traits
Primate Family Tree
Crown lemur
Orangutan
Evolution of Bipedalism
•
Anatomical 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)
(Click for interactive skeleton)
Pre-hominid Evolution
Ardipithecus ramidus 4.4 - ?
A. anamensis
mya
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
Bipedalism
Tools
Language
Reconstruction of Australopithecine
Hominid Evolution
• Homo habilis (2.0 – 1.6mya)
• H. erectus (1.9-27kyBP)
• H. heidelbergensis (800-100kyBP)
• H. neanderthalensis (300-30kyBP)
• H. sapiens (130kyBP – present)
Scale: Millions of Years BP
– H. rudolfensis (2.4-1.6mya)
Hominid Evolution
• Major Homo advances:
–
–
–
–
–
Brain size
Better bipedalism
Hunting
Fire (H. erectus)
Tools
•
•
•
•
Oldowon (H. habilis)
Acheulean (H. erectus)
Mousterian (H. heidelbergensis)
Solutrean (H. sapiens)
– Built shelters (H. heidelbergensis)
– Clothing (H. neandertalensis)
– Language (Neandertals?)
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 speech
Artist’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 Java
Dubois calls it Pithecanthropus
erectus initially, also dubbed ―Java
Man‖
finds in China called Sinanthropus
dates 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, marriage
– Less hair on body = wearing of furs, other clothing
– Wearing of furs = ability to live further north
– Quick adaptation to environment
without physical changes
– Culture is main reason H. erectus
was so successful
•
•
•
•
•
organization for hunting
ability to protect against predators
control of fire?
possible campsites
tools (Acheulean industry)
Distribution of H. erectus
Homo neanderthalensis
• discovered 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 midfacial prognathism
The skull of the classic Neandertal
found in 1908 at La Chapelle-auxSaints.
Neandertal 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 cave
Bottom: Mousterian tools
What happened to Neandertals?
• 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
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 humans
35,000 years B.P. in western Europe to
17,000 years B.P.
1,600 cc cranial capacity
Name comes from a hotel in France
Not a different species, just old Homo
sapiens from Europe
Artist’s reconstruction of a Cro-Magnon man
Archaic H. sapiens Culture
Art
Traces of art found in beads, carvings, and
paintings
Cave paintings in Spain and southern France
showed a marked degree of skill
Archaic H. sapiens Culture
Cave paintings from 20,000 years ago at VallonPont-d’Arc in southern France (left) and from
Lascaux, in southwest France
• Cave paintings
– Mostly animals on bare walls
– Subjects were animals favored for their meat
and skins
– Human figures were rarely drawn due to
taboos and fears that it would somehow harm
others
Upper Palaeolithic –
Hotbed of Culture
•
•
40 – 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
Modern Homo Sapiens
Regional-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 analogy
– Small group, low population density, nomadism,
kinship groups
• Migration
–
–
–
–
North America was the last colonized by hominids.
Beringia (land bridge) between Russia and Alaska
Asian origin of Native Americans
30,000 to 12,000 years B.P. was first migration
Human Variation
• Modern humans vary in skin color, hair
color, and eye color.
Modern Humans
• Well, we still like to
argue all these points
as we learn about
them!