Retinitis pigmentosa is a group of inheritable diseases that is characterized by gradual deterioration of the photoreceptors in the retina. The photoreceptor cells in the retina, rod cells, are light sensitive cells that are able to sense low levels of light. The frequency of retinitis pigmentosa is one in four thousand births (Deng et al., 2015; Fahim et al., 2012; Haddad et al., 2016; Shu et al., 2012) People affected by retinitis pigmentosa will typically exhibit symptoms of night-blindness first, and this will precede a loss in the patient’s visual acuity field that starts from the outer edge and gradually moves inward resulting in a much smaller visual field and loss of peripheral vision, also known as tunnel vision (Haddad et al., 2016).
Chimpanzees have what is called melanin, which is a dark brown pigment that protects them from UV radiation. Melanin is a natural sunscreen, which filters out UV radiation. It is been proven that people with high concentration of melanin in their skin heading to come from tropical areas and it has protected them from skin cancer. After all of this research, Jablonski and Chaplin then ask, “what role melanin might play in human evolution?” (170).
The tapetum lucidum is an evolutionary advantage for animals. It enables animals to see in dimmer light than the animal would otherwise be able to see in. The tapetum lucidum is useful to animals, but it also has a use to humans. Human beings use the tapetum lucidum to scan for reflected eye-shine, in order to detect and identify the species of animals in the dark and to send trained search dogs and search horses out at night. Historically, its function was regarded as simply to increase the light intensity of an image on the retina. Using eye shine to identify animals in the dark implies not only color but, also several other features. The color reciprocates to the type of tapetum
Organisms possess several types of color vision depending on what wavelengths they are sensitive to. Humans are trichromatic, because their vision is formed by long, middle and short wavelength sensitive cones (Carroll, et.al, 2009). Depending on the environment, primates will have different variations of color vision. (Melin, et.al, 2017). Routine trichromacy and polymorphic trichromacy both track different food sources. Routine trichromacy is helpful for tracking down reddish-yellow fruit and seasonal leaves while polymorphic trichromacy is helpful for tracking down ripe fruits and insects (Melin, et.al, 2017).
This article explores the effects color blindness has to approximately 300 million people around the world, how individuals are born with it, the differences between the several types, its etiology, and research that has been completed in gene therapy. He addresses the impact that color blindness has had on his own life, having the form called Deuteronomaly, which is a reduced sensitivity to green light. He details his personal thoughts on color blindness; the fact that though there is a fascination to treat the condition, he questions what the hype about it is and wonders if color deficiency is something society should want to have corrected. The author doesn't find himself disadvantaged by not seeing see the world in color as most people do, even though he does miss out on the
Achondroplasia (ACH) is the most common form of short-limb dwarfism occuring in 1 in 15,000 to 28,000 births and appears to be slightly more prevalent in females, but indiscriminent toward race (1-3). Evidence has been found in Egypt for cases of ACH dating back as far as 4500 B.C. (4). In simplest terms, ACH is a disease where the dwarfing of bones formed in the cartilage occurs (5). There are many features that accompany this disease including rhizomelic (proximal) shortening of the extremities, megalencephaly (enlarged brain), short stature, trident hand, and frontal bossing (prominent forehead) (1, 3, 4, 6-8). Expression of this gene at high levels is primarily found in cells of the nervous system and the cartilage rudiments and
Historically, the set of common characteristics among primates have been documented as a consequence of adapting to arboreal living (living in trees). Even though others placental mammals (a very diverse group of close to 4,000 species ranging everything from rodents/bats to humans) were able to adapt to various environments; such as living on land (ground-dwelling) to living in oceans (marine environments), while the primates found their adaptive niche in the trees (the place in which they survival dependent upon such as in terms of proving refugee, their source of food, its habitat, etc.). In addition, the primates were not the only ones who were able to adapt to living in the trees, other mammals were capable of adapting to this way of living, however, the majority of them continued to dependent on the land for their primary source of food. On
Food requirement variations lead to color vision being an exponentially valuable trait in the evolutionary success of the primates based on its influences in foraging behavior. If an animal is unable to discriminate a piece of fruit from being ripe or unsafe to eat, they could potentially become sick, thus negatively impacting their chances of reproduction and survival (Regan et al., 2005).
One of the most variable aspects of the eyes in primates is the sclera. The sclera in primates comes in multiple different pigments and SSI as seen in figure 2. In research on human eyes, evidence concludes that through the sclera, health, age and emotion can be detected; redden or yellow sclera detects decreased health, increased age, and even emotions of sadness or irritation, whereas bright white sclera represents increased overall health . The true purpose for the evolution of the sclera is not completely clear, but many implications can be made to help researchers better understand the complex evolution of the eye. One of the major topics for research on the eye is the discovery that the purpose of the white sclera is to amplify gaze direction whereas the darker colored sclera is to do the opposite; hide gaze direction from predators . Not only can the sclera help detect emotion and gaze but is a major factor in the evolution of communication between primates.
Did you know that almost 28% of Americans don’t know how to cook as Adults. Studies have shown that many kids that learn to cook before adulthood are more likely to live a happier life. Kids that know how to cook before they go off on their own, are less likely to eat the fatty restaurant foods that are unhealthy for your body. Most people that know how to cook, prefer to stay at home and eat home cooked meals, rather than drive out to a restaurant and eat there. Lathrop Middle School needs a cooking club because, it can make kids smarter in the culinary area, it can save money for kids in the future, and it can prevent future illnesses.
Humans have three cone cells that are extremely sensitive to Red, (620-700nm), Green (490-570nm) and Blue (450-495nm) wavelengths of light. Although these three cones are most sensitive to these wavelengths, they are still sensitive to the remaining wavelengths of visible light between 400-700nm. When a light with a wavelength of 600nm is transmitted through the retina, the Red and Green cones capture, sense and signal the brain that orange light is observed. In this case the Red and Green cones absorb light but the Green cones are less sensitive. Also, the Blue cones don’t absorb much light and are not sensitive
Melanin has played a significant role in human evolution. In this paper I will discuss the importance of melanin in its role in the human biological system and how it relates to the natural selection of suitable human life according to geography and environment.
This paper considers that focused primarily on human iris. This choice of this topic was made due to interest of wanting to provide knowledge about the factors that determine eye color. I know, like hair or skin, brown eyes are dominant over blue eye genes. I also know that a person can be identified by the retina scanners because everyone has their iris with unique structural patterns.