 Once
upon a time
and long ago, 500 million years ago to be exact, all the lifeforms on
Earth were composed of only one cell, instead of the billions of cells
that we have in our bodies today. We call these single-celled beings
microbes, and some of them such as ameba and bacteria, and some of them
are still around today.
They
reproduced by splitting in half. But there became so many of them that
they began to poison their environment (Earth) with their own wastes,
just as we today are polluting the Earth with our waste products and
burning carbon dioxide into the air which, while it doesn't affect the
Earth's climate as some believe, does create acid rain which depletes
the minerals from the soil it lands on which, in turn, reduces the
quality of food.
 So all the microbes got together to
try to think of a way to solve the problem. "How can we conserve our
resources, and not have to consume so much and create so much waste
that there is no room left for us to live our lives?" they asked.
The answer they decided upon was that
they should form colonies of many microbes, so that they would need
less space, energy and resources to live. They would produce fewer
by-products and would have protection from predators by banding
together in a group. The colonies they formed became all the
multicellular things alive today. We call banding together in a group
"aggregating".
Each
colony delegated different responsibilities to different microbes in
the colony depending on their abilities.Some microbes became the eyes
of the colony, some became the digestive and transportation systems
within the colony, and some were in charge of reproduction.
Because the microbes had reproduced
by splitting in half before aggregating, some colonies had microbes who
were identical twins of microbes in other colonies. If identical twin
microbes of different colonies were in charge of reprodcution, their
colonies could reproduce with each other. And those colonies that
could reproduce with each other became one species, evolving as time
went by into the forms they have today, if they were successful, or
reverting back into single-celled organisms or "de-volving" if they
weren't successful as colonial aggregations species.
Most multicellular (colony) species
around today such as ourselves are permanent in their aggregation and
never revert back to being microbes, but there are some living things
that still start out as microbes who get together to form colonies.
Rock lichens for example are a colony made of a fungus and an
algae microbe, or a fungus and a cyanobacterium, and some lichen
colonies are made of all 3 together. To reproduce, they have to devolve
back into microbes until they find the right partners to aggregate or
evolve with back into lichens. Sometimes, the microbes in lichens will
devolve back into microbes and never form back into lichen but will
remain microbes.
|
|
The Real Story of Evolution
