This video discusses the oldest human footprints in the
world (3.75+ mya), which were unearthed at Laetoli, near Olduvai
Gorge, in Tanzinia. These footprints led Owen Lovejoy to conclude
that even these early hominids walked with an upright, striding
gait just as modern humans do. Lovejoy suggests that this led
to remodeled pelvises and other morphological changes. His "provisioning
hypothesis" further asserts that bipedal males carried
provisions to females who were burdened with youngsters.
Also discussed in the video is the famous "Lucy" skeleton,
one of the oldest and most complete skeletons of human ancestry,
which was discovered by Don Johanson in Ethiopia's Afar
Triangle. Johanson and Tim White concluded that these fossils
constituted an early species of the previously known Australopithecus
genus. The species was named Australopithecus afarensis
after the Afar region of Ethiopia.
This touched off a debate about the nature of Australopithecus
afarensis. The "Lucy" and "First Family"
hominid skeletal remains have challenged the prevailing view
of how human evolution began--and have sparked a controversy
over the nature of ancient upright-walking creatures--as they
seem to have had small brains and primitive faces and teeth,
despite their advanced locomotion.
A key question remains: "How many species are represented
by the wealth of Afar-Laetoli hominid specimens?" Deciding
where in human prehistory to place fragmentary fossil material
is crucial to determining the ancestral relationships of extinct
species and thus to reconstructing the human family tree. Inevitably,
experts' interpretations of fossil fragments differ.
In 1972, Richard Leakey suggested the existence of two separate
lines of hominids (Homo and Australopithecus).
One, the well-known Australopithecus genus, was composed of
primitive, small-brained individuals principally adapted to
a diet of roots and hard seeds. The other was the larger-brained,
tool-using, omnivorous Homo lineage. Leakey states that Homo
is the only hominid to change to meat-eating, first as scavengers
and later as hunters.
While Homo flourished in the African environment,
its Australopithecine cousins eventually reached an evolutionary
dead end and became extinct. Leakey's model--a three-species
view for the period between 2.5 mya and 1.5 mya--was based on
his observation that the earliest australopithecines
known at the time already resembled the later australopithecines
so much that they could not also be ancestors to the very different
The "Lucy" discoveries overturned
this prevailing model of human evolution. A. afarensis
is so primitive and generalized in its features that White and
Johanson see it as conceivably ancestral to both lines of early
hominids (Homo and Australopithecus). But these
findings signal more that a repositioning of Species on the human
family tree. Small-brained Australopithecus afarensis challenges
Darwin's hypothesis, which lies behind Leakey's model. That bipedalism
evolved intelligence, tool use, and hunting.
Terms / Concepts
- bipedalism / bipedality
(human family) = biped with smaller canines
- mandible = lower jaw bone
- "provisioning hypothesis" (Lovejoy)
- "K reproductuve strategy" emphasizes the
production of few offspring, in whom parents invest
- "r reproductive strategy" emphasizes the
production of a large number of offspring with reducted
- "weapons" vs. "tools"
- "warfare," "gang attacks," "killing and cannibalism"
- "aggression" is against conspecifics
- conspecifics — members of the
- meat eating / hunting
- scavaging (as hayenas, jackels. . . .)
- diet types
- insectivorous (insects)
- frugiverous (fruit)
- herbiverous (plants)
- gramnivorous (grasses)
- carnivorous (meat)
- omnivorous (all of the above)
- opposability / prehensility
- histology = the study of tissues, esp. of their microscopic
- "very primitive" = "very ape-like" in terms of anatomy
ramidus and Australopithecus
anamensis had not been discovered yet when this
video was made
- In the 19th century and early 20th centuries "people expected
to find a large brain on a more primitive [sic.]
ape-like body," and almost wanted to find this. But the
large brain came later
- Note use of chimps as a model to explain prehistoric primate
- Oldest footprints in the world are those found by Mary
Leakey at Laetoli, and date to 3.5 - 3 .7 mya. The
Vértesszöllös footprints are from ca.
400,000 ybp. What are thought to be the oldest human footprints
in other parts of Europe are the 25,000 to 27,000 ybp
footprints from Chauvet
Cave in France.
- Mary Leakey in the video says "oldest human
prints," but it should be "oldest hominid footprints"
- short 4 - 5 ft. people (2 adults and a child)
- freestriding walk, keeping in step with one another,
left foot for left foot and right foot for right
foot, with the child stepping in the footprints
of one of the adults
- "These footprints are more evocative than
any [bone fragment] fossil."
- but footprints are actually also "fossils"
- but they did find other fossils (mandibles)
- no stone tools in the deposit, therefore "man" 3.5 mya had not reached toolmaking
- Between 8 and 4 mya in Africa there was a change
from ape (pongid)
- "The change from a quadrupedal animal to a bipedal
animal requires major anatomical change."
- free hands, tool making
- note the change in pelvis from quadrapedial
to bipedal locomotion
Teeth / Diet
- did teeth analysis looking at striations
- in 1976 did a postmortem on a 1.5+ mya Lake Turkana
(northern Kenyan) on an adult Homo
erectus from one of Richard Leakey's expeditions.
They assumed similar effects may have had similar causes.
The most complete Homo
erectus skeleton ever found, but it was diseased
(with vitamin A poisioning, perhaps do to eating to
too much raw liver?)
- The tooth analysis shows that Ramapithecus
ate the same kind of food, and that for at least 7 mya
or so, maybe longer, creatures in "the family of
man," or close to it, were eating the same kind
of things. The food is the same as the chimpanzees now
eat, i.e., they were frugivores, they ate mainly fruit.
- the earliest evidence that shows any basic change
from fruit eaters is with the 1.8 mya Homo
erectus populations, a species directly ancestral
to our own. Here, for thefirst time in history, you
have a MAJOR change in diet. They probably ate "a
little of everything," including meat, bones, and
- They looked at the teeth of Australopithecus robustus
- One problem in Prehistoric Cultures is to find a behavioral
pattern in our past that is powerful enough to make
changes useful and necessary
- "We would expect bipedalism to be a forest adaptation,
not an adaptation to the savanah."
- ". . . We have to look at a population's
method of reproduction methods of survival."
- Bipedalism is not an adaptation to hunting --
Owen Lovejoy (re the "provisioning hypothesis"
- The earliest fossil that shows any change from the
eating habits of the ancestors is Homo erectus.
had a radically different diet. About 1.5+ mya, for
the first time in human [pre]history there is a major
change in diet, from frugiverous / herbiverous to meat
- Teeth provide a clue to the diet of prehistoric animals.
Cultures / People
(1908): "One of the greatest scientific frauds perpetrated this
jaw on human cranium)
- 3 1/2 - 4 ft. tall, mature adult hominid
(her teeth were fully erupted)
- "The First Family"
- "The First Family" (close to 100 individuals, at Locality
- Are these the same or different from Mary
Leakey"s finds at Laetoli, more than 1000 miles
away, but from a similar date?
- There are three species of hominids.
Each occupied a different niche and were not competing with
one another: (1) Robust
Australopithecus, aka Paranthropus robustus
(ca. 5 ft), (2) Australopithecus
africanus (ca. 4 ft.), and Homo
habilis (ca. 5 ft., with a larger brain).
- The earliest probable hominids now include
- "Eurydice" (1.5-million to 2-million-year-old skull
of a female Paranthropus
robustus]) is more complete (27 April 2000).
Foot, " the world's first-ever find of an entire "ape-man"
skull and its skeleton (3.5 mya), was found at Sterkfontein,Transvaal,
South Africa in 1998.
- The earliest collection of hominids yet discovered
comes from Aramis (4.4 mya).
- Lothagam in northern Kenya
(5.8 - 5.6 mya?)
Man" [sic.] -- 04 December 2000
ramidus kadabba -- 11 July 2001
robustus (aka Paranthropus robustus), Homo
habilis (large brain
tool making), Homo
- Hadar (Ethiopia) (1972 - )
- Lake Turkana (fka Lake Rudolf)
erectus postmortem: The most complete Homo
erectus skeleton ever found, but it was diseased
(with vitamin A poisioning, perhaps do to eating to too
much raw liver?)
- pelvis change -- quadruped to biped
(Tanzania) (oldest hominid footprints in the world:
3.5 - 3.7 mya)
- Johanson, D. C., & Edey, M. A. 1981. Lucy: The
beginnings of humankind. New York: Simon and Schuster.
(See also summary from Science 81, No. 2, pp. 44-45,
and No. 3, pp. 44-49).
- Johanson, D. C., & White T.D. 1979 "Asystematic
assessment of early African hominids." Science,
- Leakey, M. D. 1978. "Pliocene footprints at Laetoli,
Tanzania." Antiquity, 52:133.
- Leakey, M. D. 1979. "Footprints in the ashes of time."
National Geographic, April 1979.
- Leakey, R. E., & Lewin, R. 1978. People of the
lake: Mankind and its beginnings. New York: Avon Books.
- Leakey, R. E., et al. 1976. "Fossil hominids
from the Laetoli beds." Nature, 262:460-466.
- Tuttle, Russell H. 1984. Review of The making of mankind.
American Anthropologist, 86:3:796-799.