Garrett+H.

Human Eye Color Genes
You may one day be looking into your friends eyes or even your own in a mirror and just ask yourself how your eyes became that color. There are over 378 different genes and still counting that control skin, hair and eye color. To this day, eight genes have been identified which impact eye color. Located on chromosome 15, there is the OCA2 gene which appears to play a major role in controlling the brown/blue color range. OCA2 makes a protein called P-protein that is involved in the formation and processing of melanin. Individuals at birth that have a form of albinism are because of OCA2 mutations that prevented P-proteins to be produced. These individuals have very light colored eyes. Non-disease-causing OCA2 variants (alleles) have also been identified. These alleles change P-protein levels by regulating the amount of OCA2 RNA that is generated. The allele that results in high levels of P-protein is connected to brown eyes. Another allele, connected with blue eye color, dramatically reduces the P-protein concentration.

The color of human eyes is primarily controlled by the amount and type of a pigment called melanin. Specialized cells known as melanocytes make the melanin, storing it in intracellular compartments known as melanosomes. The total number of melanocytes is about the same for all people; however the amount of melanin inside each melanosome and the number of melanosomes inside a melanocyte differs. The total amount of melanin is what determines the range of eye colors.

In humans, eye color is determined by the amount of light that reflects off the iris. Blue eyes contain small amounts of pigment in a small number of melanosomes. Irises from green–hazel eyes show medium pigment levels and melanosome number, while brown eyes are the result of high melanin levels stored in many melanosomes.

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**Finch Evolution**
The Finch evolution was first discussed by Charles Darwin, was named Darwin`s Finches. they were first collected by Darwin on the Galápagos Islands during the second voyage of the Beagle.

The birds vary in size from 10 to 20 cm and weigh between 8 and 38 grams. The smallest are the warbler-finches and the largest is the vegetarian finch. The most important differences between species are in the size and shape of their beaks, and the beaks are highly adapted to different food sources. The birds are all dull-coloured. The birds generally prefer to eat larger seeds, which are harder for their nutcracker-like beaks to break open but hold a bigger reward inside. The bigger the bird's beak, the easier it is to crack open the seeds' shell. The already small beaked finch couldn't keep up with the newly arrived large finch, which is about twice as big and dominates feeding grounds. The Galapagos finches were not as important to Darwin as is often claimed, but they are a good example of micro-evolution. They show us that finches can vary in their morphology, and that natural selection has a role in this. This study does not give evidence for macro-evolution, and does not prove that natural selection and random mutation could produce the living world as we know it from simple single-celled ancestors.

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Goalie Reflexes
If you were to have something, anything suddenly come at higher speed than your brain can compute what do you do? Do you duck to avoid it or do you make a last second attempt to catch it? Goalies in multiple sports have to make split second decisions in order to become a great goalie an to achieve an amazing paying job. Receptors at the end of the sensory neurons fire an impulse that travels at speeds exceeding 100 meters per second, about 225 miles per hour. This impulse moves down something called the sensory afferent pathway, a chain of nerve structures that transmits the nerve impulse toward the central nervous system, igniting a key component of the reflex. Think of the reflex arc as shortcut en route to a final destination. Because there is a need for an immediate response, the impulse is re-routed through the reflex arc to the spinal cord to be processed instead of going all the way up to the brain.

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