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Chapter 12

BIOLOGY 1M03 Chapter Notes - Chapter 12: Olduvai Gorge, Termite, Taphonomy


Department
Biology
Course Code
BIOLOGY 1M03
Professor
Jon Stone
Chapter
12

Page:
of 6
Chapter 12: Oldowan Toolmakers and the Origin of Human Life
History
The Oldowan Toolmakers
-the earliest identifiable stone tools are from about 2.5 mya
-at sites about 2.3 mya, researchers found an extensive array of stone artifacts,
including flakes (small, sharp chips), cores, hammer stones, and debris from
manufacturing
-these artifacts, collectively are called Oldowan tool industry, are very simple
oround stones that have been chipped
oartifacts are quite variable in shape and size
omade from different raw materials
otool industries are collections of tools that are found in a particular region
and time
-we do not know which hominin species were responsible for making tools
-it is also possible that earliest stone tools were made by species that do not
appear until later in the fossil record
-stone tools are more durable than bones, so the archaeological record is usually
more complete than the fossil record
Complex Foraging Shapes Human Life Story
-anthropologists divide foods acquired by forages into three types according to the
amount of knowledge and skill required to obtain them
othese are, in order of increasing difficulty of acquisition, collected food,
extracted foods, and hunted foods
1. collected foods can be simply collected from the environment and
eaten
2. extracted foods come from things that don’t move but are
protected in some way
these things must be processed before food can be eaten
3. hunted foods come from things that run away, and thus must be
caught or trapped
may also need to be extracted or processed before consumption
Chimp Humans
Collected 96% 10%
Extracted 4% 30%
Hunted 2% 60%
-humans depend on hard-to-learn skills to acquire food
-contemporary foraging peoples depend on extracted and hunted foods to a much
greater extent than chimpanzees do
-unlike other predators, humans must learn a very diverse set of hunting skills
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-most large mammalian predators use one of two methods: wait in ambush, or
combine a stealthy approach with fast pursuit
-efficient extraction of resources requires considerable skill
-Blurton and Jones (both from UCLA) discovered digging up deeply buried tubers
from rock soil as a complex mining operation involving much clever engineering
of braces and levers
-reliance on hunting and extractive foraging favors food sharing and division of
labour in contemporary foraging groups
-usually, men take primary responsibility for hunting large game, and women take
primary responsibility for extractive foraging
-division of labour makes sense on two grounds:
1. hard-to-learn techniques reward specialization
takes a long time to be good hunter, and it takes a long time to
learn how to dig tubers
2. because child care is more compatible with gathering than with
hunting, and lactation commits women to child care for a substantial
portion of their adult lives, it makes sense that men specialize in hunting
-reliance on meat eating favours evolution of food sharing
oif several hunters share catch, chance of starvation is much lower
-food sharing and division of labour lead to extensive flows of food between
people of different ages and sexes
-selection may have favoured larger brains, a prolonged juvenile period, and a
longer life span because these traits make it easier to learn complex foraging
methods
-complex, learned foraging techniques allow humans to acquire highly valuable or
otherwise inaccessible food resources
-meat is a much better source of nutrients that animals need than is the usual
primate fare of leaves and ripe fruit
omeat is high in protein, lipids, and is rich in energy
-humans were able to access a large supply of food by learning how to use tools
to dig them up
-if learning is valuable, natural selection will favour adaptations that make a better
learner
ofavour larger brains and greater intelligence
oreliance on complex learned foraging skills would also favour the evolution
of a prolonged juvenile period
this will generate longer life span
longer life span is costly, but added time allows learning that
produces more capable adults
-food sharing and vision of labour lead to reduced competition between males and
reduced sexual dimorphism
owhen males invest in offspring, there is less male-male competition and
reduced sexual dimorphism
Evidence for Complex Foraging by Oldowan Toolmakers
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-Oldowan toolmakers are plausible candidates for species that links early apelike
hominins to later hominins, who have more humanlike life history patterns
-contemporary foragers rely on complex, hard-to-learn foraging techniques to a
much greater extent than other primates do, and this shift can explain evolution
of main features of human life history
-contemporary experiments suggest that Oldowan tools could be used for a
variety of tasks, including the butchery of large animals
oSchick and Toth found that stone flakes struck from cobble cores can be
used for many tasks, including butchering large animals like elephants
ocores can be used for a more limited number of jobs, such as chopping
down a tree to making a stick or spear
-wear patterns on bone tools from South Africa suggest that they were used to
excavate termite mounds
oextractive foraging (commonly done with wooden sticks) is likely to leave
traces in archaeological record
oevidence suggests that hominins from this period were extractive foragers
ofound number of broken bones that had wear patterns suggesting that
they had been used as tools
oanalysis shows that the fossil tools were used for digging in termite
mounds
Archaeological Evidence for Meat Eating
-at several archaeological sites in East Africa, Oldowan tools have been found
along with dense concentrations of animal bones
-bones found belong to a wide range of animal species (pigs, horses, elephants,
hippopotamuses, rhinoceroses, and a variety of carnivores)
-along with these bones, Leakey found several kinds of stone artifacts: cores,
flakes, battered rocks that may have been used as hammers or anvils, and some
stones that show no signs of human modification or use
-association of hominin tools and animal bones does not necessarily mean that
early hominins were responsible for these bone accumulations
-there are other possibilities for the accumulation of bones
obones may have been deposited there by moving water or by other
carnivores
omaybe animals died of natural causes
-study of taphonomy provides one means to resolve questions about what
happened at sites
otaphonomy is the study of the processes that produce archaeological
sites
examine characteristics of contemporary kill sites (spots where
animals were killed, processed, and eaten)
-taphonomic analyses at Olduvai Gorge suggest that bones at most of these sites
were not accumulated by natural causes
-sediments surrounding Olduvai sites do not show any of the features
characteristic of sediments deposited by rapidly moving water
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