Energy: A World Perspective - Vishwanath (Vish) Prasad, Professor Mechanical and Energy Engineering University of North Texas ...
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Energy: A World Perspective
Vishwanath (Vish) Prasad, Professor
Mechanical and Energy Engineering
University of North Texas
vish.prasad@unt.edu
Indian Institute of Technology, Kanpur
July 29 – August 3, 2019
UNT
An attempt to provide a historical, global perspective of role of
energy in:
• Natural selection strategies and human evolution
• Control of Fire: the most critical invention of mankind
• Farming and domestication of animals: the second most
critical act
• Discovery of metal and processing methods
• Mercantilism, nationalism, and economic principles
• Discovery of fossil fuels and industrial revolution
• Population explosion and GDP
• Development and future trends
• Environmental pollution and climate change
• Global warming bringing the world together
• Challenges to alternative energies
• Future energy resources
• Security, conflicts, and hot spots
UNT
Topics and Presentation Materials
1. Energy and Human Evolution
2. Human History and Energy regimes
3. Energy: Beyond Biomass and Metal Processing
4. Energy and Industrial Revolution
5. Energy and Economy
6. Population Growth, Energy Consumption, and GDP
7. World Development Indicators
8. International Energy Outlook
9. Energy and Environment
10. Green House Gases and Global Warming
11. International Agreements
12. Energy Conflicts and Hot Spots
13. Challenges to Alternative Energies
14. Future Energy Sources
UNT
ACKNOWLEDGEMENTS
• Many facts/data, thoughts, ideas, and statements have been borrowed generously from a
large number of archival and non-archival publications, books, and websites, references to
which are given on the last slides of each topic. Most of them are not placed under quotes
to maintain the flow and continuity of presentations. Their works are highly appreciated.
• Students in my graduate courses on “Energy: The Fundamentals” and “Energy: A World
Perspective” have significantly contributed to these presentations through their home
works, take-home examinations, and term papers on selected topics.
• A doctoral student in Philosophy and Religion, Giovanni Frigo who attended my classes, has
written his dissertation on “Energy Ethics,” a topic that has not received much attention;
although Environmental Ethics is a well-established sub-discipline of philosophy. I had the
pleasure of serving on his doctoral committee. His contributions to this presentation is also
appreciated.
• Acknowledgements are also due to UNT Department of Mechanical and Energy
Engineering, particularly the former Chair, Dr. Yong Tao for supporting the creation of a
Graduate Certificate Program in Energy. Dr. Tao and I have worked on many energy
conservation research and education projects, including the Zero-Energy House at UNT,
Solar House (designed and built by engineering and architecture students) at Florida
International university (Miami), and US Future House in Beijing, completed at the time of
2008 Beijing Olympics; it is a three bedroom regular house based on US architecture and
Chinese Feng-Shui.
UNTThe slides presented by Dr. Prasad in this QIP program are
for participants’ personal use, not for public distribution or
repository such as library. They can use some materials for
their classroom instructions as appropriate.
UNT1. Energy and Human Evolution
Vishwanath (Vish) Prasad, Professor
Mechanical and Energy Engineering
University of North Texas
Indian Institute of Technology, Kanpur
July 29 – August 3, 2019
UNTLeslie A. White, "Energy and the Evolution of Culture," American Anthropologist,
Vol. 45, No. 3, part 1, July-September, 1943.
“Everything in the universe may be described in terms of energy1. Galaxies, stars,
molecules, and atoms may be regarded as organizations of energy. Living organisms
may be looked upon as engines which operate by means of energy derived directly
or indirectly from the sun. The civilizations, or cultures of mankind, also, may be
regarded as a form of organization of energy. Culture is an organization of
phenomena – material objects, bodily acts, ideas, and sentiments – which consists of
or is dependent upon the use of symbols2. Man, being the only animal capable of
symbol-behavior, is the only creature to possess culture. Culture is a kind of
behavior. And behavior, whether of man, mule, plant, comet, or molecule may be
treated as a manifestation of energy. Thus we see, on levels of reality, that
phenomena lend themselves to description and interpretation in terms of energy.
Culture anthropology is that branch of natural science3 which deals with matter and
motion, i.e., energy, phenomena in culture form, as biology deals with them in
cellular, and physics in atomic, form.
UNT--------------------------------------------------
1. By “energy” we mean “the capacity for performing work.”
2. “A symbol is a thing the value or meaning of which bestowed upon it by those who
use it. I say ‘thing’ because a symbol may have any kind of physical form; it may
have a form of material object, a color, a sound, an odor, a motion of an object, a
taste.
The meaning, or value, of a symbol is in no instance derived from or determined
by properties intrinsic in its physical form: the color appropriate for mourning may
be yellow, green, or any other color; purple need not be the color of royalty;
among the Manchu rulers of China it was yellow. The meaning of the word ‘see’ is
not intrinsic in its phonetic (or pictorial) properties. ……… The meaning of symbols
are derived from and determined by the organisms who use them; meaning is
bestowed by human organisms upon physical forms which thereupon become
symbols.” Leslie A. White, "The Symbol: The Origin and Basis of Human Behavior,"
Philosophy of Science 7, no. 4 (Oct., 1940).
3. “Natural science” is a redundancy. All science is natural; if it is not natural it is not
science.
UNTThe purpose of culture is to serve the needs of man. These needs are of two kinds:
(1) those which can be served or satisfied by drawing upon resources within the
human organism alone. Singing, dancing, myth-making, forming clubs or
associations for the sake of companionship, etc., illustrate this kind of needs and
ways of satisfying them. (2) The second class of needs can be satisfied only by
drawing upon the resources of external world, outside the human organism. Man
must get his food from the external world. The tools, weapons, and other
materials with which man provides himself with food, shelter from the elements,
protection from his enemies, must likewise come from the external world. The
satisfaction of spiritual and esthetic needs through singing, dancing, myth-making,
etc., is possible, however, only if man’s bodily needs for food, shelter, and defense
are met.”
The history of human culture can therefore be regarded as the progressive
development of utilization of energy sources external to man as well as search for
new energy sources and their utilization, energy conversion, and energy
technologies.
UNTENERGY: A conserved quantity that represents the ability to work. Advances in
understanding of energy, its use and exploration, and discovery of new resources
have produced unparalleled transformation of society as well as economic growth.
Critical Fundamental Concepts of Energy
• Energy cannot be created or destroyed
• Life depends on the sun
• Earth’s energy balance determines climate
• Human evolution, civilizations, and culture are energy-driven and transitions in
energy systems transform culture
• Natural selection operates on energy strategies
• Energy systems impair ecosystem and human health
• Energy quality varies among sources
• Net energy is an ultimate constraint
• Energy drives economic growth
• Per capita use of energy is a measure of standard of living, health, joy, and
spirituality
• Control of energy resources causes violent conflicts and greatly influences global
politics
UNTLAWS OF THERMODYNAMICS
First law of thermodynamics: Energy is always conserved, it cannot be created or
destroyed. However it may change from one form to another. This implies that the
total amount of energy and matter in the Universe remains constant.
Second law of thermodynamics and Concept of Entropy:
Clausius Statement: It is impossible for any system to operate in such a way that
the sole result would be an energy transfer from a cooler to a hotter body.
Kelvin-Planck Statement: It is impossible for any system to operate in a
thermodynamic cycle and deliver a net amount of energy by work to its
surrounding while receiving energy by heat transfer from a single thermal
reservoir.
Entropy Statement: It is impossible for any system to operate in a way that entropy
is destroyed.
The 2nd law of thermodynamics means that orderly structures, patterns, and
arrangements of energy and materials tend to drift towards disorder by themselves.
This movement towards a greater state of entropy occurs without outside
interference. Thus, the tendency for energy and materials to move from an ordered,
low entropy state to a disordered, high entropy state is a spontaneous process.
UNTENERGY IN EVOLUTION: BASICS
Photosynthesis: Critical to Life on Earth
• Photosynthesis is the physico-chemical process by which plants, algae and
photosynthetic bacteria use light energy to drive the synthesis of organic
compounds.
• In plants, algae, and certain types of bacteria, the photosynthetic process results
in the release of molecular oxygen and the removal of CO2 from the atmosphere
that is used to synthesize carbohydrates (oxygenic photosynthesis). Other types of
bacteria use light energy to create organic compounds but do not produce oxygen
(anoxygenic photosynthesis).
• Photosynthesis provides the energy and reduces carbon required for the survival
of virtually all life on our planet, as well as the molecular oxygen necessary for the
survival of oxygen consuming organisms.
• In addition, the fossil fuels currently being burned to provide energy for human
activity were produced by ancient photosynthetic organisms.
• Although photosynthesis can occur in only a few microns across, the process has a
profound impact on the earth's atmosphere and climate. Each year more than
10% of the total atmospheric CO2 is reduced to carbohydrates by photosynthetic
organisms.
UNTPhotosynthesis, Contd.
• Most, if not all, of the reduced carbon is returned to the atmosphere as CO2 by
microbial, plant and animal metabolism, and by biomass combustion. In turn, the
performance of photosynthetic organisms depends on the earth's atmosphere and
climate.
• Since the beginning of large scale use of coal (industrial revolution) the increase in
the amount of atmospheric CO2 created by human activity has a profound impact
on the performance and competition of photosynthetic organisms. This effect is
expected to continue to grow in the near future.
• Knowledge of the physico-chemical process of photosynthesis is essential for
understanding the relationship between living organisms and the atmosphere as
well as the balance of life on earth.
• The overall equation for photosynthesis is deceptively simple. In fact, a complex
set of physical and chemical reactions must occur in a coordinated manner for the
synthesis of carbohydrates.
UNTAutotroph: An organism that can produce its own food using light, water, carbon
dioxide, or other chemicals. Because autotrophs produce their own food, they are
sometimes called producers.
Most autotrophs use photosynthesis to make their food by using energy from the sun
to convert water from the soil and CO2 from the air into a nutrient called glucose, a
type of sugar. The glucose gives plants energy. Plants also use glucose to make
cellulose, a substance they use to grow and build cell walls.
• Plants are the most familiar type of autotroph, but there are many other
autotrophic organisms. Algae, which live in water and whose larger forms are
known as seaweed, is autotrophic. Phytoplankton, tiny organisms that live in the
ocean, are autotrophs. Some types of bacteria are also autotrophs.
• All plants with green leaves, from the tiniest mosses to towering fir trees,
synthesize, or create, their own food through photosynthesis. Algae,
phytoplankton, and some bacteria also perform photosynthesis.
• Some rare autotrophs produce food through a process called chemosynthesis. They
do not use energy from the sun to produce food. Instead, they make food using
energy from chemical reactions, often combining hydrogen sulfide or methane
with oxygen. Organisms that use chemosynthesis live in extreme environments,
where the toxic chemicals needed for oxidation are found.
UNT• Bacteria that live in the deep ocean, near hydrothermal vents, also produce food
through chemosynthesis. A hydrothermal vent is a narrow crack in the seafloor.
Seawater seeps down through the crack into hot, partly melted rock below. The
boiling-hot water then circulates back up into the ocean, loaded with minerals
from the hot rock. These minerals include hydrogen sulfide, which the bacteria use
in chemosynthesis.
• Autotrophic bacteria that produce food through chemosynthesis have also been
found at places on the seafloor called cold seeps. At cold seeps, hydrogen sulfide
and methane seep up from beneath the seafloor and mix with the ocean water and
dissolved carbon dioxide. The autotrophic bacteria oxidize these chemicals to
produce energy.
Autotroph in the Food Chain:
To explain a food chain—a description of which organisms eat which other organisms
in the wild—scientists group organisms at trophic, or nutritional, levels. There are
three trophic levels. Because autotrophs do not consume other organisms, they are
the first trophic level.
• Autotroph are eaten by herbivores, organisms that consume plants. Herbivores are
the second trophic level. Carnivores, creatures that eat meat, and omnivores,
creatures that eat all types of organisms, are the third trophic level.
UNT• Herbivores, carnivores, and omnivores are all consumers—they consume
nutrients rather than making their own. Herbivores are primary consumers.
Carnivores and omnivores are secondary consumers.
• All food chains start with some type of autotroph (producer). For example,
autotrophs such as grasses grow in the Mountains. Deer are herbivores (primary
consumers), which feed on the autotrophic grasses. Carnivores (secondary
consumers) such as lions hunt and consume the deer.
• In hydrothermal vents, the food chain’s producer is autotrophic bacteria. Primary
consumers such as snails and mussels consume the autotroph. Carnivores such as
octopus consume the snails and mussels.
• An increase in the number of autotroph will usually lead to an increase in the
number of animals that eat them. However, a decrease in the number and variety
of autotroph in an area can devastate the entire food chain. If a wooded area
burns in a forest fire or is cleared to build a shopping mall, herbivores such as
rabbits can no longer find food. Some of the rabbits may move to a better
habitat, and some may die. Without the rabbits, foxes and other meat-eaters that
feed on them also lose their food source. They, too, must move to survive.
UNTHeterotroph
• Heterotrophs are organisms that, unlike autotrophs, cannot derive energy directly
from light or from inorganic chemicals, and so must feed on other life-forms. They
obtain chemical energy by breaking down the organic molecules they consume
through a process known as heterotrophic nutrition.
• Heterotrophs include all types of organisms, such as animals, fungi, bacteria and
protists. (Protists are a diverse collection of organisms, primarily microscopic and
unicellular, or made up of a single cell. The cells of protists are highly organized
with a nucleus and specialized cellular machinery called organelles.)
• There are four types of heterotrophs, classified based on their source of food.
Herbivores consume only plants and are called primary consumers, since they
directly obtain nutrients from the autotrophs. Carnivores consume other animals,
including herbivores, thereby getting the nutrients indirectly from the autotrophs.
Carnivores are called secondary consumers if they eat herbivores and tertiary
consumers if they eat other carnivorous organisms.
• Omnivores consume both plants and animals and can be considered as primary,
secondary and tertiary consumers, depending on their diet. For example, humans
not only consume plants in the form of vegetables and fruits, but also meat from
various sources. Detritivores are heterotrophs that consume dead organic matter
and can include bacteria, fungi, insects, and worms.
UNTTHE HUMAN ANIMAL
• The extent of human energy use is a consequence of the human capacity for
extrasomatic adaptation which makes it possible for human beings to adjust to a
wide variety of novel circumstances without having to wait many generations for
evolution to change their bodies.
• Human culture has long been recognized as a highly specialized, extrasomatic
means of adapting to a rapidly changing environment. However, humans are not
unique in having a means of adaptation which is transferred from generation to
generation through non-biological means. Information transmission may occur via
the mechanisms of social facilitation, observation, and imitation. The differences
between human and non-human adaptive behaviors are differences in degree, but
in kind.
• The necessity of successful cultural transmission is imperative among humans.
Observational learning and imitation had been selected over many generations, for
the adaptive advantages it is conferred upon its practitioners. This bent towards
observational learning - as well as a relatively elongated learning period - are
specific adaptations to specific environments. The acquisition of language, for
example, occurs effortlessly among children as a result of a biological imperative to
its retention and use.
UNT• A comparison of somatic and extrasomatic adaptation can show just how
remarkable an ability this is: If longer, sharper teeth are adaptive for a predator,
animals with teeth that are slightly longer and sharper than those of their fellows
will have a slight reproductive advantage, so that genes for longer and sharper
teeth will have a slightly greater likelihood of being passed on. And, over the
course of time, the teeth of average members of the population will come to be,
little by little, longer and sharper.
• In contrast, a human hunter can imagine a longer, sharper arrowhead; he can
fashion it with nimble hands; and if it is really more efficient than the short, blunt
arrowheads that everybody else has been using, his peers will soon adopt the
new invention. The chief difference between the two means of adaptation is
speed: Humans can adapt, relatively speaking, in a flash.
• Extrasomatic adaptation is possible because humans are, in the idiom of the
computer age, programmable. Somatic adaptation is like building a hard-wired
computer to perform a certain task better than a previous hardwired computer.
UNT• Programmability, the ability to learn, is not unique with human beings, but they
have developed the capacity much further than any other species. Programm-
ability probably developed as an evolutionary response to pressure for flexibility.
The ability to make use of a variety of different resources runs deep in the human
background.
• Programmability, and the consequent capacity for extrasomatic adaptation, have
made it possible for human beings to advance a very old evolutionary trend at a
vastly increased rate. Humans are the most recent in the series of heterotrophs
that use increasing amounts of energy, but they differ from other species in this
lineup in their ability to use more energy without further speciation. Over the
course of humanity's short history, greater and greater amounts of energy have
been used by the same biological species.
UNTEXTRASOMATIC ENERGY
• Some human innovations have dealt with the fate of energy channeled through
metabolic processes. The development of weapons, for example, made it possible to
focus somatic energy so as to obtain high-energy foods with much greater efficiency.
Man became a hunter. This may have been the innovation that let Homo erectus
prosper and permitted his species to migrate out of the African cradle, pursuing
game throughout the tropics of the Old World. Similarly, the use of clothes brought
about a conservation of bodily energy that helped make possible the conquest of
more temperate regions.
• But the most remarkable human innovation is the use of extrasomatic energy,
wherein energy is made to accomplish human ends outside the bodies of its users.
And the most important source of extrasomatic energy, by far, is fire. Fire was used
by Homo erectus in Northern China more than 400,000 years ago; there are
evidences that it may have been used long before that.
• The exploitation of animal power played an important role in the densification of
population that was at the root of civilization. Animals pulled the plow, animals
carried produce to market, and animals provided a protein-rich complement to a diet
of grain. Wind power was soon utilized to carry cargo by water. But fire remained the
most important source of extrasomatic energy.
UNT• Until quite recently, however, there was no real innovation in the fuel used to make
fire. The development of charcoal improved upon the energy density of untreated
wood, and made a substantial contribution to metallurgy. For hundreds of thousands
of years, fire was made with the tissues of recently deceased organisms, principally
wood.
UNTNATURAL SELECTION AND ENERGETICS
• The fundamental object of contention in the life-struggle, in the evolution of the
organic world, is available energy. Basically, in the struggle of existence the
advantage must go to those organisms whose energy-capturing devices are more
efficient in directing the available energy into channels favorable to the
preservation of the species.
• The first effect of natural selection thus operating upon competing species will be
to give relative preponderance (in number or mass) to those most efficient in
guiding available energy in the manner indicated. Primarily the path of the energy
flux through the system will be affected.
• But the species possessing superior energy-capturing and directing ability may
accomplish something more than merely to divert to its own advantage energy for
which others are competing with it. If sources are presented, capable of supplying
available energy in excess of that actually being tapped by the entire system of
living organisms, then an opportunity is furnished for suitably constituted
organisms to enlarge the total energy flux through the system. Whenever such
organisms arise, natural selection will operate to preserve and increase them. The
result is then not a mere diversion of the energy flux through the system of organic
nature along a new path, but an increase of the total flux through that system.
UNT• Again, if sources exist, capable of supplying matter, of a character suitable for the
composition of living organisms, in excess of that actually embodied in the system
of organic nature, an opportunity is furnished for suitably constituted organisms to
enlarge the total mass of the system of organic nature. Whenever such organisms
arise, natural selection will operate to preserve and increase them, provided
always that there is a residue of untapped available energy. The result will be to
increase the total mass of the system, and, with this total mass, also the total
energy flux through the system, since, other things equal, this energy flux is
proportional to the mass of the system.
• To recapitulate, in every instance, natural selection will so operate as to increase
the total mass of the organic system, to increase the rate of circulation of matter
through the system, and to increase the total energy flux through the system, as
long as it is presented with an unutilized residue of matter and available energy.
This may be expressed by saying that natural selection tends to make the energy
flux through the system a maximum, which is compatible with the constraints to
which the system is subject.
UNT“Natural selection operates on evolutionary strategies that capture and allocate
energy among competing uses. Every living organism must use energy for six
purposes: maintenance, growth, storage, reproduction, protection, and
obtaining more energy. The natural world is the dazzling array of different
strategies for accomplishing these tasks.”
A. J. Lotka, “Contribution to the Energetics of Evolution,” Biology, Vol. 8, 1922.
UNTENDOTHERMS AND ECTOTHERMS
• Endotherms are warm-blooded animals which maintain a constant body
temperature independent of the environment. The endotherms primarily include
the birds and mammals; however, some fish are also endothermic. If heat loss
exceeds heat generation, metabolism increases to make up the loss or the animal
shivers to raise its body temperature. If heat generation exceeds the heat loss,
mechanisms such as panting or perspiring increase heat loss. Unlike ectotherms,
endotherms can be active and survive at quite low external temperatures, but
because they must produce heat continuously, they require high quantities of
“fuel” (food).
• Ectotherms are cold-blooded animas, whose regulation of body temperature
depends on external sources, such as sunlight or a heated rock surface. The
ectotherms include the fishes, amphibians, reptiles, and invertebrates. The body
temperatures of aquatic ectotherms are usually very close to those of the water.
Ectotherms do not require as much food as warm-blooded endotherms of the
same size, but most cannot deal as well with cold surroundings. Ectotherms are
affected more by the weather change because they show specific behavior
dependent on the condition of the weather.
UNT• The animals that come under the Ectotherms system don’t need to eat as much as
the endotherms because they have no intention to convert the food into heat. The
Crocodiles and alligators are the major examples of Ectotherms. They are capable
of remaining alive for few weeks or even months without eating anything. But in
order to accomplish this target, the Ectotherms have to hang immobile during
most of the day for the prime goal of saving their inner energy for conducting their
basic tasks including the process of eating, mating, and defending the territory in
which they and their families live.
• In contrast, the Endotherms can produce far more energy than the Ectotherms.
The eating habits of the Endotherms must be established on regular basis for their
survival. The Mammal is the best example of the Endotherms animal group that is
able to produce more heat and thus can live more active life than reptiles. The
Endotherms therefore have to eat far more to produce their own heat, stay active
and survive; they need to eat more compared with the Ectotherms.
• As noted earlier, autotrophs such as green plants produce their own food via
photosynthesis, while heterotrophs get their food by consuming other organisms.
Humans store energy in the form of fat, while most trees store excess amount of
energy generated during the summer in their roots. Elephants produce one
offspring and invest substantial energy in rearing it, while most fish produce huge
numbers of offspring and invest little energy in parenting.
UNT• The desirability of various strategies to obtain energy from the environment and
allocating it among different uses is determined by the natural selection.
• Natural selection strategies that work are rewarded while strategies that do not
work are punished. If a strategy works, an individual will have sufficient supplies of
energy and will allocate it in ways that allow the individual to produce many
offspring that survive and prosper. If the strategy is inherited by the offspring, the
number of individuals that follow this strategy will increase in the next generation.
If the strategy does not work, the individual will produce few offspring and these
offspring will have a smaller probability of survival. As a result, the number of
individuals that follow this strategy will decrease in the following generations.
• If the relative success of a strategy persists for many generations, the strategy that
generates the most energy and allocates it among maintenance, growth, storage,
reproduction, and protection in a way that generates the greatest number of
successful offspring will prevail. Other strategies may appear, but they will fail and
disappear.
• The role of natural selection in “choosing” strategies can be illustrated by “why
breathe oxygen?”. One pathway allows organism to convert food to energy without
oxygen, which is termed anaerobic respiration. Another pathway allows organisms
to convert food into energy, which is termed as aerobic respiration.
UNT• Most organisms on the planet use aerobic respiration. Why? An organism that
respires a molecule of glucose anaerobically obtains 47 units of energy while the
aerobic pathway generates 686 units of energy. Given the same amount of food,
the aerobic organism has 15 times more energy available. All other things being
equal this difference allows aerobic organism to expend greater efforts to maintain
itself, to grow, to reproduce, to protect itself, and to obtain more food. Based on
this advantage, organisms that depend mainly on aerobic respiration have been
able to outcompete organisms that are capable of anaerobic respiration only in the
environment where oxygen is present. As a result aerobic organisms are
predominant form of life on the planet.
UNTENERGY AND RESOURCES
• Resources are "An available supply that can be drawn upon when needed" and
"Means that can be used to advantage." In other words, resources include all the
things found in nature that people use, not just the things people use for survival,
but things they use for any purpose whatsoever. This is a very broad concept, as
required by the nature of the defining animal. The resources used by other animals
consist primarily of food, plus a few other materials such as those used for nest
building. But for Homo sapiens, almost everything "can be used to advantage."
• For something to be a resource, it must be concentrated or organized in a
particular way, and separate, or separable, from its matrix. Ore from an iron mine is
a resource in a way that garden soil is not, even though both do contain iron.
Similarly, wood from the trunk of an oak tree is a resource in a way that wood from
its twigs is not.
• Using a resource means dispersing it. When we quarry limestone and send it off to
build public monuments, or when we mine coal and burn it to drive turbines, we
are making use of a concentrated resource, and dispersing it. A large, continuous
mass of limestone winds up as a number of discrete blocks spread around in
different locations; and coal, after briefly giving off heat and light, becomes a small
amount of ash and a large amount of gas. Resources may be temporarily
accumulated in a stockpile, but their actual use always results in dispersal.
UNT• Resources may be used for their material properties or for the energy they
contain. Bauxite is a material resource, while coal is an energy resource. Some
resources may be used either way; wood, for example, may be used as a
construction material or burned in a wood stove, and petroleum may be used to
make plastics or to power cars.
• The exploitation of all resources requires an investment in energy; it takes energy
to knap flint or drill for oil. The exploitation of energy resources must entail a
good return on investment; unless the energy they release is considerably more
than the energy used to make them release it, they are not worth exploiting.
• Since nothing is a resource unless it can be used, resources are defined by the
technology that makes it possible to exploit them. Since exploiting a resource
always requires energy, the evolution of technology has meant the application of
energy to a growing array of substances so that they can be "used to advantage.“
UNT• Search for new energy and other resources leads to migration. Better climatic,
weather, and living conditions can add to the extent of migration and its pattern.
This was particularly true in the migration of Homo Sapiens out of Africa,
beginning at least 120,000 years ago. And, this is also at the roots of colonization
by Europeans and their permanent settlements (1500s to mid 19th Century) as
well as migration to the New World, particularly North and South Americas and
Oceania (1800s-1930). Slavery by Britain and United States (1550 to the end of
the 18th century) and indentured labors by Britain (1834-1917) are also (cruel)
examples of acquisitions of horse powers, i.e., energy.
• In addition, in the brief time since humans began living in the cities, they have
used more and more energy to exploit more and more resources.
UNTMap of Human Migration
UNTMap of Human Migration
UNTMap of percentage of people with European ancestry,
largely based on Ethnic self identification (Census Data)
UNTCONTROL OF FIRE, DIET AND BRAIN SIZE OF MAMMALS
• As noted earlier, the most remarkable human innovation is the use of extraso-
matic energy, that is made to accomplish human ends/tasks outside the bodies of
its users. And the most important source of extrasomatic energy, by far, is the fire.
• Fire is universally accepted as vital to human life, with countless expressions and
uses in the modern world. It was regarded by Darwin as the ultimate discovery
made by humanity, excepting only language.
• The control of fire by early humans was a turning point and a breakthrough
adaptation in evolution. To understand this, we need to consider at least three
distinct and potentially intergrading forms of fire use: first, fire foraging for
measures across landscapes; second, social/domestic hearth fire, for protection
and cooking; and third fires used as tools in technological process for firing
pottery.
• Fire improved efficiency in manipulating the surrounding environment (safety
from predators, clearing land, visibility during night time). Homo sapiens was the
only mammal that changed its natural environment according to its needs of the
time. Fire helped tremendously in the production and storage of food thus
affecting the population density. Fire must have improved sanitation and helped in
the extermination of microorganisms and insects.
UNT• Humans learned to light fires in the dry season and to transform the landscape
through grazing and cultivation. Substantial human impacts on burned area in
Africa were directly responsible for the development and evolution of human
primitive societies.
• During the Paleolithic and Mesolithic ages, fire was used for a variety of other
reasons like facilitating travel, killing vermin, hunting, regenerating plant food
sources for both humans and livestock, and even warfare among tribes. These land-
management practices had profound impacts not only on fire regimes but also on
the landscape vegetation pattern and biodiversity. Commonly, woody, closed
canopy shrublands and woodlands were displaced by fast-growing annual species
that provided greater seed resources, travel, and hunting and planting
opportunities.
• Fire also led to improved nutrition by cooked proteins. Indeed, cooking of plant
foods may have triggered brain expansion by allowing complex carbohydrates in
starchy foods to become more digestible and in effect allow humans to absorb
more calories. The higher food energy that cooking supplied, as well as the
detoxifying effects of heating which increased the diversity of available food,
contributed to a fitness advantage in the early humans. Cooking also implied a
delay in food consumption, which required the development of social abilities for
the distribution of tasks within the group.
UNT• Evidence suggests that shift to cooked food by Homo erectus helped in the
development of large number of brain neurons and thus had a major positive
contribution to the rapid increase in brain size.
• It is also suggested that eating cooked food is more “natural” for the human
digestive system, because the human digestive system may have evolved to deal
with cooked foods, and that cooking explains the increase in hominid brain sizes,
smaller digestive tract, smaller teeth and jaws and decrease in sexual dimorphism
that occurred roughly 1.8 million years ago. It is argued that raw meat and
vegetables could not have provided the necessary calories to support the hunter–
gatherer lifestyle. The control of fire even allowed increased access to various food
items, like honey and toxin-rich foods.
UNT• A striking growth in human brain size is one of the major developments in Homo
Sapiens. It has risen from an average ca 600 to 1300 cc in the course of the
Pleistocene (from 2.6 million to 11,700 years ago). As a larger brain is costly in
energy, its evolution needs explanation. The social brain hypothesis aims to
explain the phenomenon in terms of increases in group size and pressures
towards social cognition. Social brain calculations propose rapid change at this
stage, and a link with language origins.
• In addition to the many benefits that fire provided to early humans, it also had a
major impact on the innovation of tool and weapon manufacturing. The use of fire
by early humans as an engineering tool to modify the effectiveness of their
weaponry was a major technological advancement.
• Hearth, a constructed fireplace, was first used during the Upper Paleolithic period
for cooking and burning clay figurines. From the Middle Paleolithic period, hearth
and kiln, built of clay, were used to heat-treat stone for making stone tools and to
burn clay for ceramic objects. The analysis of tools at multiple sites shows that the
source stone materials were systematically manipulated with fire to improve their
flaking properties. Heat treatment predominates among silcrete tools at ~72,000
years ago and appears on the south coast of South Africa.
UNTLeft to right: orangutan, gorilla, chimpanzee, human, and Neanderthal skulls overlaid with an illustration of
the corresponding brain, [I T Fiddes, Human-Specific NOTCH2NL Genes Affect Notch Signaling and Cortical
Neurogenesis, Cell, Vol. 173, 1356-1369, 2018].
UNT• The Neolithic agricultural revolution required fire to alter the natural vegetation
from perennial-dominated to annual-dominated landscapes. It is postulated that
people preferred to live in fire-prone places because the burning provided them
advantages for hunting, foraging, cultivating, and livestock herding.
• Not only the human control of fire likely required the cognitive ability to
conceptualize the idea of fire, it also served as a community-building tool and
allowed for the facilitation of spoken language.
• As humans recognized the benefits of fire and those who did not have the
capability to make fire looked to join those who did, small societies were formed,
and the framework of early cultures was laid.
UNTPALEOLITHIC ERA: Tools and Fire of Hunter-Gatherers
• For at least 3 million years, during the evolution of Homo sapiens from a primitive
mammal, mankind used tools and fire unlike the other animals to carry the basic
activities of hunting/fishing. These changes helped in their survival. Humans are
very unusual among animals in combining the two functions that helped in their
evolution.
• Extrasomatic ability to develop language and communicate effectively were very
important and greatly helped in establishing a primitive use of nature and its
resources. Wild animals’ meat, fish, plants, tubers, trees were used for feeding an
increasing population. Some of the a available materials were used for protection,
e.g., tools, arrows and sticks.
• The story of controlled fire started from the Paleolithic era (250,000-100,000 B.C.E.)
that lasted until the beginning of farming. The agricultural civilization, ~10,000
B.C.E. was the next important development.
UNT• At around 20,000 B.C.E. the success of their life-style with the help of fire resulted
in the distribution of hunter-gatherers all around the world. At this time population
on Earth was estimated to be around 8-10 million. But the increase of population
of hunter-gatherers could not be sustained forever and they had to find new forms
of energy, increasing food production, gathering and storage. Predators, diseases,
high newborn mortality, short life expectancy, and low fertility kept the population
in balance with natural resources than from increasing rapidly.
UNTEvidently, the very first milestone of human’s utilization of external energy was the
mastery of fire. Fire was a conquest of independent groups of humans in several
parts of the world and the main source of energy for several millennia. The
utilization of fire for heating and cooking, using biomass (mainly wood) as fuel,
dates back at least 4–500,000 years. The level of firewood consumption in different
regions in pre-modern times may have varied from 1 kg per person per day to 10 kg
in cold climates, equivalent to between 3,000 and 40,000 Calories. With fire,
calories per person increased dramatically from 2,000 to 3,000–4,000 per day or
more, that is 5–6 GJ per year. However, the efficiency in its use was very low.
With control of fire, it created light and thus improved safety in human
settlements, a fact that promoted the expansion of habitation. After incorporating
fire, the human incorporated certain selected plants and animals that could provide
them with useful products.
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