Antiquity of Humanity
Basal Hominids
Australopithecines and Paranthropus
Early Homo
Later Homo
Theories of Human Origins
Cosmologies
– Religious explanations for our origins, ie.
Genesis
Mayan Origin Myths
Scientific explanations
– Using Scientific Method to explain origins
Evolution
Theory of Natural Selection
Taxonomy
Scientific nomenclature-developed by Linnaeus.
Kingdom, Phylum, Order, Class, Family, Genus,
Species.
Genus capitalized and italics, species lower
case and italics.
– Australopithecus afarensis
Names generally reflect region where they come
from.
Fossil species, not biological species.
Basal Hominids (6-4 mya)
Sahelanthropus tchadensis
Ardipithecus ramidus
Australopithecus anamensis
Orrorin tugenensis
Recent specimens that date to this time
period may represent the earliest on the
human line, but not a lot of data yet. Most
have small brains and were probably
bipedal.
Bipedality Evidence
Female Gorilla
Australopithecus africanus
Modern Humans
Pelvis, Femur and FeetComparisons
Some Basal Hominid Remains
Sahelanthropus tchadensis
Ardipithecus ramidus
Orrorin tugenensis
Australopithecus afarensis
aka “Lucy” (ca. 4-3.5 mya)
“Lucy”
•Discovered by Donald Johanson and
Tom Gray in 1974 at Hadar in
Ethiopia (all specimens E. Africa)
•Lucy was an adult female of about
25 years.
•About 40% of her skeleton was
found, and her pelvis, femur (the
upper leg bone) and tibia show her to
have been bipedal.
•She was about 107 cm (3'6") tall
(small for her species) and about 28
kg (62 lbs) in weight.
Australopithecus africanus
(ca. 3-2.5 mya)
•Small cranial
capacity (350-400
cc)
•Small body size
•Very similar to
“Lucy”
•Found in S. Africa
Australopithecus garhi (2.5 mya)
Major specimen is
partial cranium with
upper jaw.
Brain size 450 cc
May be ancestral to
Homo habilis
http://cas.bellarmine.ed
u/tietjen/Human%20Nat
ure%20S%201999/austr
alopithecus_garhi.htm
Paranthropus
Chronology (2.5-1.5 million years ago)
Diagnostic Features (large heavy jaws,
sagital crest, small brained, bipedal)
Species
–Paranthropus boisei
–Paranthropus robustus
–Paranthropus aethiopicus
Paranthropus boisei
Paranthropus robustus
Paranthropus aethiopicus
Later Human Evolution:
Homo habilis (ca. 2.5-1.6 mya)
H. habilis finds
Homo habilis
Homo habilis is the earliest known
species of the genus Homo; that is, the
first human species.
– It existed from approximately 2.5 to 1.6 million
years ago in east Africa.
– Only a few fossil remains have been
discovered so far, but these specimens
exhibit a clear trend toward larger brain size.
– H. habilis brains are about 30% larger than
those of A. africanus.
Homo habilis
A nearly complete skull of H. habilis was
discovered in 1972 at Koobi Fora on the shores
of Lake Turkana in Kenya. Its age is estimated
at 1.8 million years and its brain capacity at 800
cc.
Some anthropologists argue that the variations
appear to indicate that several separate species
of humans existed; other scientists lump all the
individuals together in a single species.
Homo habilis
Brain size much bigger than Aus. (500-800)
Teeth smaller, thinner enamel, more parabolic
dental arcade.
Skulls rounder, less prognathic, jaw muscles
reduced.
East and South Africa, same time as robusts.
Handyman, associated with Pebble choppers
(more later).
This reconstructed
skull was found in
1972 on the shores of
Lake Turkana.
Represents the oldest
individual human yet
discovered.
Homo habilis
Age:ca. 1.8 million years
Date of Discovery:October 1968
Location:Olduvai Gorge, Tanzania
First Stone Tools:
Oldowan Pebble Choppers
Tool Technology
Oldowan Pebble Choppers
rounded pebbles
portions broken to form sharp edge
flakes used for butchering
These crude hand axes and stone flakes could have been manufactured
as needed or as opportunity arose. The fracture lines of stones create a
sharp cutting surface capable of butchering fairly large animals. The photo
above right shows a modern anthropologist skinning a calf with a stone tool
made just as ancient Homo habilis would have done.
Environment
The background of the
photo shows the kind of
environment in which this
earliest-known human
species lived--open bush
and savannah country in
east Africa.
This must must have
been a very challenging
environment, filled with
large predators.
?
Behavior
Meat eating
Home base, food sharing, sexual division
of labor.
Archaeological evidence
– Animal bones and stone tools at sites
(Olduvai)
– Hunting or Scavenging?
– Probably scavenging.
The Homo habilis Debate
It was once thought that the evolution of the
genus Homo was an example of anagenesis,
the continual and gradual change of one parent
species into its daughter species in a linear
fashion.
As the fossil record began to expand and more
early human fossils were found dating to the
period between 2 million and 1 million years
ago, some questions as to the validity of this
hypothesis were raised.
Below are two fossils, shown to scale. KNM ER
1470 is to the left, and KNM ER 1813 is to the right.
Originally, both were assigned to the species Homo
habilis, with ER 1470 thought of as male and the
smaller ER 1813 a female in a strongly dimorphic
species. However, the anatomies of the two skulls
differ considerably.
Differences
Homo habilis
Height 1.0 metres
Physique Relatively long arms
Cranial Volume 500 – 650 cc
Known Date2.0 – 1.6 million
years ago
Distribution Eastern & S? Africa
Skull form Relatively small face;
nose developed
Jaws/Teeth Thinner jaw;
smaller, narrow molars
Homo rudolfensis
Ca. 1.5 metres
Robust
600 – 800 cc
2.4 – 1.6 million years
ago
Eastern Africa
Larger, flatter face
Robust jaw; large
narrow molars