Scientists think the earliest version of the eye was formed in unicellular organisms, who had something called 'eyespots'. These eyespots were made up of patches of photoreceptor proteins that were sensitive to light. They couldn't see shapes or colour, but were able to determine whether it was light or dark out.
The crystalline connection. The earliest eyes were probably just simple eyespots that could only tell the difference between light and dark. Only later did some animals evolve spherical eyes that could focus light into images. Crucial to these image-forming eyes was the evolution of lenses that could focus light.
The results indicate that our kind of eye—the type common across vertebrates—took shape in less than 100 million years, evolving from a simple light sensor for circadian (daily) and seasonal rhythms around 600 million years ago to an optically and neurologically sophisticated organ by 500 million years ago.
The first proto-eyes evolved among animals 600 million years ago about the time of the Cambrian explosion. The last common ancestor of animals possessed the biochemical toolkit necessary for vision, and more advanced eyes have evolved in 96% of animal species in six of the ~35 main phyla.
Humans are the only animals with obviously visible eye whites, with irises that are much more prominent and therefore readable.
5–Black Eyes
There's an eye disorder known as aniridia which makes the eye appear to have “no iris.” In truth, there is a small ring of iris tissue but it is so small and the pupil is so large that it can look like the eyes are completely black. It is due to a chromosome mutation.
Similarities in human, chimpanzee, and bonobo eye color patterns revealed. Summary: Researchers have revealed that chimpanzees and bonobos share the contrasting color pattern seen in human eyes, which makes it easy for them to detect the direction of someone's gaze from a distance.
Researchers have long debated when humans starting talking to each other. Estimates range wildly, from as late as 50,000 years ago to as early as the beginning of the human genus more than 2 million years ago.
In human evolution, the eyes came first.
Human evolution from aquatic ancestors is heavily documented and supported by evidence found in fossils. We know that our fishy forefathers used their limbs to move into the shallows and then up onto land, eventually evolving into four-legged vertebrates.
Because the nerve fibers coming from the rods and cones need to come together as the optic nerve, which then has to travel back to the brain, there needs to be a hole in the retina through which the optic nerve can travel. This hole creates a blind spot in each eye.
Homo sapiens (modern humans) emerged around 200,000 years ago in Africa, but the mutation that causes blue eyes did not appear until sometime around 10,000 years ago.
Adam is the name given in Genesis 1-5 to the first human. Beyond its use as the name of the first man, adam is also used in the Bible as a pronoun, individually as "a human" and in a collective sense as "mankind".
German craftsmen are credited with this invention in 1835. To make these glass eyes, a tube of glass was heated on one end until the form of a ball was obtained. Various colors of glass were used like paintbrushes to imitate the natural color of the eye.
Eyes and other sensory organs probably evolved before the brain: There is no need for an information-processing organ (brain) before there is information to process. A living example are cubozoan jellyfish that possess eyes comparable to vertebrate and cephalopod camera eyes despite lacking a brain.
The chromosomes a child inherits carry genetic information that determines eye color. Differences in the copies received from each parent causes variations in the amount of melanin produced. A region on chromosome 15 has a big part in determining eye color. The OCA2 and HERC2 genes are located in this region.
Blue-eyed? Thank a genetic switch that turns off your body's ability to make brown pigment in your peepers. Researchers have finally located the mutation that causes blue eyes, and the findings suggest that all blue-eyed humans share a single common ancestor born 6000 to 10,000 years ago.
The most distantly related animals that share our olfactory receptors are known as lancelets. They look a bit like sardines with their heads cut off. They split off from our own ancestors about 700 million years ago, not long before the evolution of the brain and eyes.
It is quite baffling that we have two eyes and require the use of two eyes simultaneously, even though we still have a sense of vision if we cover one of our eyes. The reason why we have two eyes is to enable two things in our brain, namely depth perception and an increased field of view.
Q: Why do we have two eyes, two ears and only one mouth? A: So that we can see and hear twice as much as we say.
The Adamic language, according to Jewish tradition (as recorded in the midrashim) and some Christians, is the language spoken by Adam (and possibly Eve) in the Garden of Eden.
Linguists have also “reconstructed” the mother language that all these languages come from. It is called Proto-Indo-European and was spoken nearly 5,000 years ago!
Humans have flexibility in the mouth, tongue and lips that lets us form a wide range of precise sounds that chimps simply can't produce, and some have developed this complex voice instrument more than others.
Although chitons look very simple, these mollusks have a very sophisticated shell. Its outer layer contains up to 1000 tiny eyes, each a bit smaller than the period at the end of this sentence.
Chameleons have some of the strangest eyes on the planet, which are able to move independently of each other. This results in almost 360-degree vision. The reptile can also switch between monocular vision - when both eyes are used separately - and binocular vision, when both eyes are used to look at the same scene.
If you encounter an aggressive lion, stare him down. But not a leopard; avoid his gaze at all costs. In both cases, back away slowly; don't run.