Global Change I devoted
most of its time to an examination of the physical, geological and chemical
processes that causes changes to the earth’s
atmosphere and composition in the past and at present. Global Change 2 will add another dimension
to this equation – the role of human culture.
Human’s are a driving force in the world
today and actually control many of the processes that cause global
change. Our goal is to understand that
these are actually the products of human and cultural evolution and the role
of humans has increased relatively recently.
We want to briefly examine the evolution of hominids, the development of dependency on tools, the beginning and importance of fire, and the origin of language and its role in human society.
Human primate ancestors were
forest dwelling only 6-7 million years ago in
This fossil primate is known
Geological and climatic forces
were not constant or like those today during this period in hominid
prehistory. Volcanoes were a fact of
life and a cooler climate impacted the distribution of edible plants and the
composition and distribution of the forest.
Click here to
see a hominid family tree.
ramidus, our reputed primate fossil ancestor, the Australopithicines
evolved, radiated throughout east and
Australopithecus anamensis is the earliest fossil form that has been identified and dated to ca. 4.5 million years ago. It was not a tall animal and shows evidence that it was ground dwelling. It did have pronounced sexual dimorphism with adult males larger than females and males having larger canine teeth. It depended upon its physical strength for protection and for subsistence pursuits. It lacked tools, fire, and speech as we known it.
is the well-known “Lucy” excavated in
Australopithecus africanus is important because it has been found in
Bipedalism is an important hominid
trait. Walking on two legs allows the
hands and arms to be free to carry food, to carry infants, and to bear
sticks, bones, or stones for protection.
This physical development was significant for the development of family
life and eventual dependency upon tools.
Evidence of bipedal comes from reconstruction of leg anatomy and
actually footprints from Laetoli in
The diet of the
Australopithecines consisted of plants, most likely fruits, leaves, and
grass. The examination of use marks on
the teeth of A. africanus suggests a
pattern from a predominantly vegetable diet.
However, they may have engaged in scavenging food from kill sites of
Their technological base was
minimal. There are no tools made by
these creatures but they may have used bones and stones for protection and
sticks to dig roots. Use of these
natural products was mostly expedient with little if any modification. They lacked fire.
Social life is not known. The physical characteristic of infant
skeletons suggest that they were born prematurely relative to other primates
and therefore depended upon the mother at least to nurture and to protect
them for several years before they could survive alone. The large male canines could provide
protection but also serve a role to preserve a dominance hierarchy in the
group. Their social life may have been
one of “group families” with multiple female adult participation in child
rearing and male provisioning a came with food carried from elsewhere.
Symboling is the expression of abstract
ideas through speech or material objects.
Body paint is a form of symbolic expression and the designs are symbols. We have no evidence that they were
physically able to produce sounds as we do or to communicate with more than
yells, grunts, or hand gestures but not as a grammar or complete expression
of an idea beyond an immediate warning or other problem facing them.
The impact on the environment by
Australopithecines was minimal. They
did not hunt or use
fire. They did make and occupy
campsites for short periods of time that left small spatial signatures on the
landscape but no major scars or transformation of the vegetation or
extinction of animals.
About 2.5 million years ago
there were several species of Australopithecines in
was bipedal, showed sexual dimorphism, but had a larger brain than did
Australopithecines. Brain development
suggests that it relied more on reasoning and thought than on instinct. It has been suggested that parts of the
brain were evolving to permit speech.
The hallmark of habilis was its tools.
They are called Oldowan and are pebble choppers, an implement made from a
stone pebble with several flakes deliberately removed from two sides to form
a cutting edge. In other words, these
tools evidenced pre-planning and formed a tradition regarded as the Basal
Paleolithic starting 2.5 million years ago.
They were baseball sized and could be held easily in their small hands.
Their diet continued to be
dominated by vegetation but evidence exists for scavenging and breaking bones
to recover the nutritional marrow
inside. Large stone called manuports were carried to campsites to serve
as anvils for breaking bones.
Social life may have been
developing toward families with male and female infant nurturing. The exact
nature of this arrangement is unknown.
Although there is no marked
environmental destruction, the potential for a hominid impact on the
environment was increasing.
evolved into Homo erectus. This happened sometime around 1.8 million
years ago in
The control of fire is one of
the most important developments in human history. By doing so erectus could cook food and
thus make it more digestible through chemical transformation. For example, starches in roots could be
broken down and made easier for complete digestion. Toxins in plants could be destroyed;
bacteria and other harmful agents in putrefied meat could be destroyed with
heat. In addition, fire allowed
expansion into new environments by providing light, warmth, and protection
from predators. The potential for
environmental change was present by employing fire to hunt game and to burn
plant communities to stimulate production.
The first fire is found 500,000
years ago at
Other notable developments are
in the realm of technology. Erectus
was a hunter and not afraid to kill megafauna. Fire-hardened wooden spears have been found
The social life of erectus
is reflected in the arrangements of the camps. These suggest hearth groups that may have
been occupied by monogamous family groups.
The division of labor is reflected in the activities conducted around
the hearth that distinguish food preparation and
cooking from tool making and hunting. A recognizable settlement pattern for these groups of probably
related family members include basecamps,
seasonal camps, resource procurement sites, and kill and butchering sites.
Symboling is apparent in erectus
times. By 150,000 years ago the
anatomy of the throat could make a variety of controlled sounds we would
recognize as speech. Whether or not
the spoke is another unresolved story.
However, some archaeologists believe that the ability to lead an organized
social life and to possess shared symbols indicates that language was present. Erectus used red ochre (iron oxide)
for paint and body art.
Homo erectus was the first hominid to have a noticeable impact on the environment. It could hunt, control fire and leave evidence of camps still present today.
H. erectus lived from about 1.8 million to 100,000 years ago. It is ancestral to modern man, H. sapien sapiens and H. sapiens neandertalensis.
Homo erectus is the first human
radiation out of
It moved into the
The Neanderthal problem. The source of the Neanderthals
continues to be debated. Neanderthals
were thick boned, sloping browed human who were adapted physically for the
cold climate of glaciated
The evolution into different
forms of Homo sapiens, modern man, relates to a general but contentious
theory of modern human origins. It is
the multi-regional theory of hominid
evolution, which contends that no one place or continent was the source
of modern humans but many were after the spread of erectus.
Neanderthals subsided by hunting and gathering. The hafted stone points on spears and made the points by a special new technique that enabled them to remove many flakes from a single block of stone. These are called Mousterian tools or Middle Paleolithic. There social life was one of families organized into kinship-based bands. Their symbolic structure was obvious. They buried their dead, sometimes practiced cannibalism, and had a bear cult that venerated the giant cave bear by placing its skull and other parts on special alters. Most significant they may have depended upon true speech or language.
from Juan Luis Arsurga, et al's Atapuerca,
happened to the Neanderthals is an open debate. Some claim that they were killed off
directly or indirectly (out competed) by recently arriving modern man from
Another theory calls for a
second major migration from
The Upper Paleolithic technology
was based upon the most efficient stone tool techniques that we have examined
to date. The removed numerous blades
from a block of stone and then formed them into a variety of tools. Knives, scrapers, gouges, engravers,
harpoon barbs were all made from blades or deliberately broken pieces of blade. They had many kinds of finely made bone
tools including needles that they used to make tailored clothing and hide
tents. They wove carrying bags from
plant fibers, made leather straps for bearing burdens. Boats were part of their technology.
Symboling was predominant in their
life. They depended upon language and
had elaborate art as we know from cave paintings in
The greatest impact on the
environment was modern humans after 30,000 years ago. They now had the technology to enter and
live in the
Peopling the World
Fire, tents, burden straps, and
tailored clothing allowed Upper Paleolithic people in
Today we briefly reviewed the
major trends in human physical and cultural evolution. We discussed the importance of bipedal
locomotion and the beginnings of stone tool production. We examined the first spread of humans from
Important words are highlighted as bold in the text.
Take the Self-Test for this lecture
Klein, R. 1999 The Human Career. 2nd
· Lieberman, P. 1990 Uniquely Human: The evolution of speech, thought, and selfless behavior. Harvard
Mellars, P.A. 1996 The Neanderthal
Pfeiffer, J. 1978 The Emergence of humankind. Harper & Row,
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