Natural and Artificial Food:
Slide Show
Main topics:
a natural process: photosynthesis
an artificial process: agriculture
Part One: What is Food?
All living organisms use energy.
This includes YOU! Your body has stored
energy, which you burn up all day.
But why don't you run out of energy?
Where does more energy come from?
Your energy comes from FOOD, of course! But
what is food?
Food is other organisms.
Their bodies also have stored energy, so when
you eat them you take their energy.
This is true whether we
eat the organisms whole...
or in processed form.
OK, but where do those other
organisms get their energy?
The animals eat plants,
and other animals.
But where do plants get their food?
The plants created their own food,
inside their bodies.
Plants make sugars, by combining
• water, from the soil
• carbon dioxide, from the air
• light, from the sun
This is photosynthesis, which means to
create ("synthesize") using light ("photo").
All food started with photosynthesis.
Even when we eat other animals, we
are eating plant sugar-- indirectly.
You run on solar energy!
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Part Two: Natural vs. Artificial Food
For millions of years, people got food by
hunting and gathering.
• Hunting means to kill wild animals.
• Gathering means to collect wild plants.
Hunting and gathering required great work and
knowledge. Wild animals are hard to catch, and
edible plants are hard to find. So hunting and
gathering could only feed a few people. Earth's
human population was much smaller.
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About 10,000 years ago, various peoples
started breeding plants and animals.
People wanted plants and animals that
gave them more food.
This was the Agricultural Revolution.
People started sowing (planting) plants.
They kept the biggest and yummiest seeds.
The next year, those seeds grew into plants
that also had big, delicious seeds.
By doing this
over and over,
people in
Mexico turned
teosinte grass
into corn.
People also started herding animals-protecting and controlling them.
People let big, fat, tame animals have babies,
who would be yummy and tame like their
parents. This is how people made tough,
skinny boars into fat, friendly pigs.
wild European boar
Domesticated (tame) pig
These plants and animals were now partly
artificial; humans had puposely reshaped them.
(This is what we call artifice or art.)
The opposite of artificial is
natural, but even artificial things
are partly natural. For example,
people didn't create corn's roots
or leaves or seeds-- but they did
make its seeds bigger.
Natural things are wild; they do what they like.
Artificial things are tame; they do what we like.
Most people kept hunting and gathering, even
after they started herding and planting.
But the change was very important, because
herding and planting people tend to . . .
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guard crops and herds, so they live in one place
eat more food, so their population grows
have extra food, so they develop markets
develop cities, writing, and large governments
Here's the bottom line:
The world you know-- its cities, governments,
markets, writing, and manufacturing-- exists
because of agriculture. Farmers make enough
food so that everyone else can do other things.
Without agriculture, you would be outside
right now, looking for something wild to eat.
Photo Credits
EPA
USDA
NASA
NPS
LOC
BLM
NOAA
DOE
USAID
USDOT
CIO
USGS
USFWS
U.S. Senate