So far in this series we have witnessed the evolution of complex muticellular life
starting with no more than simple organic molecules.
We have seen how self polymerizing molecules can kick start evolution,
how the genetic code can evolve through purely natural means,
how simple asexual organisms can give rise to complex sexual reproduction,
and finally how unicellular organisms evolved into multicellular organisms.
But many have argued that intelligence is different.
While life can form naturally from organic molecules
and evolve on its own into the myriad of forms we see today,
intelligence cannot.
A common creationist argument is that intelligence requires an intelligent agent.
So while life may evolve naturally,
intelligence clearly requires a god,
sorry I mean intelligent designer.
Before continuing with this video I feel the need to deconstruct this argument.
If human intelligence is the product of god,
then god by definition must be intelligent.
However, if god is intelligent,
then there must be a being of higher intelligence to have created god with its intelligence,
and that intelligent being must also have required an intelligent being to have created it,
and on and on and on.
Now you will argue that god does not need a creator.
However, making such a claim negates your original assertion
that all intelligent requires an intelligent creator.
Therefore the argument that all intelligence must come from intelligence
which ultimately comes from god,
fails.
You know it truly is sad how creationists obviously feel the need
to justify their faith with logic and reason
yet fail miserably time and time again.
Okay, so back to the question at hand.
Intelligence, where did it come from?
Before we answer this question we need to define what we mean by intelligence
or at least give examples of processes that can only be performed by a being with intelligence.
Two such processes we might include as signs of intelligence
are the ability to make decisions and the ability to learn.
Now the question becomes,
what is the simplest organism that can both make decision and learn.
The answer is in fact quite surprising, as bacteria possess both of these abilities.
The best known example of how bacteria make decisions
involves the metabolism of lactose in E.coli.
Here's the problem faced by E.coli.
It can gain energy by metabolizing lactose,
however, if there is no lactose around
it shouldn't waste energy producing the lactose metabolizing enzymes.
The way E.coli decides whether or not to produce the lactose metabolizing enzymes
is through a single protein, the Lac Repressor.
When lactose isn't around,
the lac repressor is free to bind a stretch of DNA
known as the lac operon promoter,
and thereby block RNA polymerase from binding
thus preventing transcription.
However, when lactose is around,
lactose binds to the lac repressor,
changing its 3D shape
thus making it no longer able to bind DNA.
Now the lactose metabolizing enzymes
can be transcribed.
But what about learning.
Bacteria actually learn about their environment over generations
through evolution by natural selection.
After being exposed to an environment containing predominantly nylon as a food source,
a species of Flavobaterium rapidly evolved,
selecting for a single nucleotide insertion,
which formed a new gene allowing it to digest nylon.
This is also a wonderful example of how evolution can increase information stored in DNA.
Over generations the population can be seen as "learning" how to digest nylon.
Some may see these examples of proto-intelligence as a stretch from our everyday concept
and would argue that critical thinking should be included in our definition,
and that learning should be able to occur within a generation,
not just across them.
And while we have the colloquial phrases,
"he made that decision with his gut",
or "he expressed emotions from his heart",
or "the memory was in her muscles",
we all know that these are all processes performed by our brains.
Every thought we have, sensation we experience, decision we make,
emotion we feel, or memory we recall,
is ultimately the product of the electrical and chemical activity in our brains.
And while proto-intelligence may be possible in single celled organisms,
true higher intelligence, cognition, requires a central nervous system.
So the question of the origin of intelligence now becomes a question of the origin of our brains,
a topic that will be the subject of my next video.
Until then, make good use of the intelligence you have
Think about it.