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I am Caelum, and you are watching the Nature Chanel

How long have you been doing this, biological research I mean."

"Well, if I am being honest, it's a little more complicated than that, or perhaps less complicated if you look at it. Sure, I have a master's degree in zoology, but I wouldn't call myself a researcher, I just.... love animals and bugs , and I love learning about the other species. Its so exciting to meet with something or someone new. I always just want to learn how they tick, how it all works."

"So you enjoy your job."

"The humans have a saying, if you love your job you'll never work a day in your life, and I love my job."

"That doesn't seem to be a philosophy you share with your brother."

"... ..."
"I'm sorry, I know you didn't really want to talk about him, but you have to give us a little bit of leeway. I mean look at it from our point of view. Mendex has done documentaries on humans before, and based on what you have said, the contents of those documents have been extremely harmful for human/GA PR."

"People like my brother are the reason that Tesraki get such a bad rap sometimes, obsessed with money and power. That's a misrepresentation of Tesraki culture, and a lot of Tesraki just sit around and allow it to happen, no, my brother would have you think that all Tesraki care about is money for money's sake, no matter the costs, but growing up our father did his best to teach us one critical thing, and that was to pick out something you loved to do and be good at it. Our culture is based around the economy yes, but do you know why that is....?"

"No.... I can't say I do."

"It's because Tesraki love to work. Tesraki culture is based more around competition to succeed than it is about money. Once upon a time being Tesraki meant being the best at whatever you set your heart on, but somewhere along the way some people got it into their heads that the sign that you were good at our job was how much money you make. This is not the case, and I stand by the values that my father taught me, and the Values that the average Tesraki follows. It really twists my tail that the kind of people who have power in the GA and in our government are the kind of people who can convince the rest of the galaxy that we're selfish and only care about the accumulation of wealth."

"You seem passionate about this."

"I'm passionate about a lot of things. It just, really bothers me that there are Tesraki who feel lesser because the job they love isn't lucrative. There were Tesraki involved in the Drev you know, real brave soldiers who went out to risk their lives, and here we have people saying that they only did that because they weren't smart enough to do anything else. I disagree.... I had a brother in the war you know."

"You did?"

"Yeah, I... I haven't seen him in a long time. I think, I think maybe he thinks that his family is disappointed in him for the choices he made. When he left to join the war he got into a big row with our parents, and things were said out of anger that I don't think any of them meant. They were really just worried about his safety, and because of that I'm not sure if I will ever see him again."

"I'm sorry."

"Me too."

***

Mid Mericanda

The sun rises over a marshy grassland. Mother earth is in a good mood today, and her skies are clear. She won't be plagued by electrical storms or blizzards. It is approaching winter, but the autumn sky is cool and clear, it isn't too hot and it isn't too cold. Deciduous trees are beginning to shed their leaves, preparing for the long winter months ahead, where the sun's light will be meager and temperatures could job to -20 degrees well below freezing, but today the weather hovers in the comfortable mid-sixties.

The perfect weather for hunting.

The grasslands may look safe, but this colorful male bird has no idea what is waiting for him in the grasslands, concealed behind layers of camouflage.

Humans are omnivorous creatures evolving from a primarily fruitarian diet with some bugs mixed in, to a more variable palate. This fact is one of the reasons that humans are so adaptable. They have the most widely varied diet, they can and have been known to eat meat, fungus, plants, fruit, and even inedible objects on one or two occasions. They have the most varied diet out of all the sentient species, and one of the most varied diet out of all the animal kingdom aside from maybe pigs or grizzly bears.

Many people make the assumption of assuming that humans eat their meat raw like other predators, however close scientific study and the examination of human dietary constraints demonstrate that humans rarely eat meat raw, aside from fish. At one point in human evolution, humans might have eaten their meat raw, however over time, with the availability of fire, cooked meat made the tough feverous structures easier to digest and break down. With the softening of the meat also came the shortening and tightening of the human jaw.

In its current iteration, the average human would have difficulty eating raw meat, and their stomachs, evolved from years of eating cooked meat often fall to the dangers of bacterial infections caused by undercooked delicacies. The human jaw may be one of the most powerful muscles in their body, but it certainly isn't used to tear apart prey animals.

In fact, many humans have never participated in their evolved hunting technique of chasing prey to exhaustion, advanced machinery and the original creation of the slingshot have made it possible for humans to avoid getting to close to their food, which was an evolutionary advantage when you aren't as tough as the prey you are hunting.

Contrary to popular belief, humans are not indestructible, and when stacked up against predators or even prey animals on their own planet, they often, woefully fall short.

It may not look like it, but this human is on the hunt, hunkered down in a low trench, the human uses the natural ecology around him to blend in with specially made clothing to mask him from the eyes of the animals that live here. If he stays still and quiet enough, he might be able to get close.

But not too close.

His eyes scan the grasslands for signs of movement, his ears perked for the call of the colorful birds he is hunting. He does not move, and neither does his companion.

Dog sits at his feet, a couple thousand years of symbiotic friendship and human genetic meddling have made this creature the perfect hunting companion for the human because what would be better than having an apex predator on your side.

The two of them wait, dog resting silently at his side waiting only for the command of his partner.

The human eye continues to move over the grasslands hunting for any sign of movement.

The human eye itself is one of the most complex systems in the human body. Light passes in through the cornea, a hard outer layer, and in through the aperture of the iris. The clear layers of the human eye contain no blood vessels and absorb oxygen through direct contact with the air, the only part of the human body that can do this. Once through the cornea the light passes through the pupil which is simply the small aperture opening surrounded by the colorful ring you see in a human eye. This ring is a sphincter of muscle which expands, and contracts based on the amount of light in the environment. It is bright outside right now, which means the pupil is narrowed to a small pinpoint.

Light passes through the eye and is focused on the lens which can be flattened or plumped by special muscles inside the eye, which are used to focus human vision. These muscles are rapid and fast acting. From there the light travels to the very back of the eye called the retina. At first the eye bypasses the light sensitive cells and excess light is absorbed into the very back of the retina , a thin melanin layer that is almost completely black. This layer helps to keep light from scattering inside the eye and confusing the rods and cones with too much information.

Creatures with albinism, or an inability to produce melanin, will almost always have poor vision due to a lack of melanin in this part of the retina as well as extreme light sensitivity.

From here the light actually travels backwards up these light sensitive cells, called rods and cones before being sent down the optic nerve. Rods are cells that are primarily light sensitive and only see in black and white. They are located in greater clusters at the very edges of the retina. Rods have lower acuity than cones do, but they can operate in low level light unlike cones cannot. This means that if you go far enough in a human's peripheral vision, they are only seeing in black and white, though this is not something that a human would notice as their brain tends to fill in those areas with assumed color based on the rest of the environment.

Cones on the other hand and located in greater clusters at the center of the retina and are positioned most heavily over the fovea, a small indentation on the retina that constitutes the highest level of visual acuity in human vision. The fovea is very small and takes up around two degrees of the human visual field. If a human were to hold their hand out in front of them, the tip of their thumb is all the fovea covers, which is an incredibly small area of focus.

Human eyes have three cones which work mostly with three wavelengths of light, which for the purposes of this documentary we will list as Red, Green and blue, though you might hear someone saying Cyan magenta and yellow. Each cone responds differently to the different wavelengths of light, and certain color combinations of light give the perception of color despite their only being three color sensitive cones.

After traveling back up the length of the cell, this information is shot down feverous clusters where they connect at the beginning of the optic nerve. The optic nerve takes up a portion of the retina, giving humans a blind spot.

Humans have many blind spots In their eyes resulting from the optic nerve and the various blood vessels that block the back of the retina, however the human brain compensates for these blind spots and fills in details with accurate conjecture.

A flash of movement.

The human's eyes immediately dart to find the object, muscles contract and the lens changes shape, focusing light onto the fovea, this light is shot back into the optic nerve and up into the thalamus where it makes it's first stop. The thalamus is the reason that humans can "See" before they actually see. The optic lobe of the human brain resides in the very back of the skull, and sometimes nerve impulses just aren't fast enough to allow the human to react in that amount of time.

This is where the thalamus comes in. Do you remember before when I was talking about the rods in the human eye? Well as it turns out rods are also motion sensitive, and the corresponding optic nerve fibers pass through the thalamus in a very specific location. This location in the thalamus is linked to most major senses in the human body and acts as a relay point. The Thalamus receives information on pain, hearing, sight, and movement before the major sensory centers in the brain does. The thalamus is also linked to the control of those muscles which control the movement and focus of the eye.

If a human hears a loud noise, this information reaches the thalamus first, and based on thousands of years of evolution, the human head will turn, and the eyes will focus in that direction before the brain has even heard the noise. If you were to throw soemthing at a human's head, the Thalamus would see it before the optic lobe does, giving the human enough time to duck or catch the object, however this only works with moving objects.

This strange phenomenon can result in soemthing known as: blind sight.

Blind sight comes as a result of working eyes, and thalamus but a damaged on nonfunctional optic lobe. This human will claim to be blind, and unable to see, but will duck if you throw an object at them, and have the ability to navigate a room.

From there the optic nerves leave the thalamus on the other side of the brain crossing over to the opposite side and projecting the image upside down and backwards onto the optic lobe. This goes for almost everything in the human body. The right hand is controlled by the left motor cortex and hearing in the left ear is processed in the right auditory cortex of the temporal lobe.

From here special cells in the brain itself respond to different elements of the image. There is a corresponding cell in the brain for each orientation and length of a straight line and each cell fires only when that length and orientation is present.

He knows where his prey is now. With a whistle the dog is off thundering into the reeds. Its barking stirs up the birds which take to the air with a screech. Light travels like a lightning bolt through the human's eye processed every second by thousands of cells. This lightning bolt reaches the thalamus and the head turns as the first bird breaks from cover, alerted by the sudden movement.

With incredible coordination, the human eyes follows the path of the bird, and the gun is brought up to line with the focus of the fovea.

This bird doesn't have a chance.

Human and dog have done it again.

This system isn't full proof of course, the human has missed plenty of times. There are plenty of points of failure along this chain, but today he will eat well all thanks to the smooth operation of his eye, and the thalamus.

***

Please join us next week and join us on a journey as we delve deeper into the complexities of the human body.