Consciousness is perhaps the biggest riddle in nature.
Stripped to its core meaning,
consciousness is what allows us to be aware both of our surroundings and of our own inner state.
But thinking about consciousness has this habit of taking us round in circles.
We all intuitively know what consciousness is.
It's what you're experiencing here, right now.
But once we try to pinpoint just what exactly it is, it leaves us grasping at thin air.
And not just us, philosophers and scientists struggle to define consciousness.
Different schools and ideas compete with one another, but no one has come close to figuring it out.
It's unsettling to realise that we don't understand what makes us aware of ourselves and the world.
In this fuzzy area, consciousness and intelligence are also related, although they are not the same.
We'll talk in greater depth about theories of consciousness and intelligence in other videos.
Like much of what makes us human,
our consciousness is likely to have evolved from less complex forms,
as a product of evolution by natural selection.
It has probably emerged from an immense several 100 million years sequence of countless micro steps,
that together make up a sort of gradient of consciousness.
What was the first step on this path from the non-conscious
to the basic consciousness that ultimately led to the convoluted consciousness we humans enjoy today?
Take a stone.
The consensus is that a stone is not conscious. Though, not everyone agrees even on this.
Some panpsychists claim that a lump of rock may have an inner life.
However, there are no real grounds for any such assumption since stones never show behaviour.
Their inner life can neither be proven nor disproven.
A more common starting point is with the living things.
A living thing, or a self, is a part of the universe that sustains itself and makes more of its kind.
To do so, it needs energy.
And this is where an awareness of the world comes in handy.
The original function of consciousness was probably to direct a mobile self that was short of energy
to a fresh supply of food.
On the smaller scales of life, you don't need to be aware to find food.
Trichopax adhaerens - one of the simplest of all animals moves around haphazardly.
It slows down in the presence of food, and speeds up in its absence.
This is highly effective, and makes the tiny creature spend more time where there is food
than where there is not.
But it never moves in a particular direction towards a particular target,
and there's no need for it to be conscious of its environment.
The first major step towards consciousness
was probably taken when mobile selves started to move themselves directionally.
Moving towards what was good for them, say food, and away from what was less good,
say someone else who thought that they were food.
Take Dugesia tigrina - a tiny worm known for its funny face.
Sometimes the worm is hungry, and sometimes not.
This means that when it moves,
the worm self is not simply producing an automatic response to an external stimulus,
but that its actions depend upon its inner, physiological state,
whether it's hungry or sated.
When it's just eaten, the worm is less energetic,
but when starved for a while, it will move itself in the direction of tasty things.
It uses chemoreceptors on its head to smell its environment,
and guide it in the direction where the scent of food is strongest.
After finding and eating a meal, our worm buddy heads back to a dark sheltered spot to digest it in safety,
until it's hungry again.
But animals that blindly follow their sense of smell don't have a concrete objective in view.
They still lack any sense of where they are heading.
So, the next step on the ladder of consciousness is to add some perception at a distance,
Vision adds context and depth to our world.
With vision comes a sense of the space we and our food exists in.
It adds a whole new dimension to awareness, and is a huge step towards more familiar consciousness.
An optical apparatus, like an eye, enables us to visualise our goal and lock onto it.
But even at this stage, a self is only able to pursue its food as long as it sees it.
So, the next logical step needs to happen on the inside.
To visualise food in its absence, for example,
a self needs to create some sort of inner representation of the world.
Now, an animal can continue looking for food, even when it escapes its sensory range.
Because of this inner representation of what is relevant in the world,
it can remain focused on its food and its desire to get it.
Our self now exists in a world it can get familiar with.
The ability to remember things has emerged.
Thanks to memory, animals can be distracted from the pursuit for a few seconds,
but quickly continue their path afterwards.
A related phenomenon is called 'object permanence'.
This describes our awareness that things continue to exist even when we can't see them.
This cognitive skill is enjoyed by some mammals and birds, and perhaps other animals too.
Human babies tend to develop this ability around the time they turn eight months,
while baby chickens show this ability within a day or two of being born.
The capacity to remember a thing in its absence suggests at least a basic sense of time.
A sense of time is a big step on the ladder of consciousness.
It may also enable a self to look forward from the present moment and anticipate the future.
Adult chickens, for example, are able to resist a meal put in front of them if they expect to receive a bigger meal
as a prize for holding back for a while.
This sort of delayed gratification means there is an ability to visualize a reward that only exists in the future,
which can be quite a challenge even for adult humans.
Western scrub jays are experts in delayed gratification.
They show an even more elaborate sense of the future when they hide food in a cache
to retrieve it at a later date.
The scrub jays will even rehide their food if they become aware that a potential thief has been watching them.
This means that they know that there are other hungry selves out there,
who are aware and see the world from their own, different perspective.
Crafty scrub jays can sort of read the mind of their fellow birds.
This ability to mind-read is crucial for complex levels of consciousness.
By putting yourself in the position of others, you can outsmart a rich competitor,
or empathise with a hungry friend.
Language takes the ability to read minds and represent what is absent to a whole new level.
Words enable us to construct hypotheses about the world,
make detailed plans, and to communicate them with others.
Words enable us to think about ourselves and our place in the universe,
and even about our own consciousness, which is something we'll be doing more in future videos.
So, what is the origin of our consciousness?
It probably began as the directed motion of a hungry self towards a source of food.
With the survival benefits, this gave it over competitors that moved at random or not at all.
It probably all started with the urge for more food.
So, even with the sophisticated consciousness that allows us to dream about space,
build skyscrapers, or obsess about novels,
it's not surprising that we can't stop thinking about where we'll get our next meal.
Collectively, we've put so much thought and ingenuity into getting food,
that we can now just get our food to come to us with little conscious effort.
This video is part one of a three-part video series relating to big questions of life and the universe,
made possible by a grant from the Templeton World Charity Foundation.
You can find our sources and further reading in the video description,
or get the consciousness book by Rupert Glasgow for free- link down below.
If you want to help us make more videos, you can do so on patreon.com,
or get one of our posters from our shop.