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Evolution, evolution is a very touchy subject. It is also a very debatable subject in regards to many different things and the way that they’re taken. But it is something that I personally find very interesting. There’s something that I question actually and it’s not exactly on topic of evolution but instead of an occurrence, extinction. We all know that extinction is the dying off of something, but specifically in this case species. So my question is, if extinction is so posed to be a natural part of life on Earth, why should we care about protecting endangered species?

Humans are known to be of a complex species, however it is no mystery that Homo sapiens (humans) are also categorize as mammals. There are many components and characteristics that define a mammal; hair being on of them. Epidermal in origin, hair is made up of a complex structure. Mammals are the only animals in which hair is found on. Even "hairless" mammals, such as pigs, elephants, dolphins, and other cetaceans (another word for marine mammals) are partially covered with fine short hairs. Hair has many functions within itself. The many functions of hair include the retention of heat, attraction of mates, protection of skin, sexual dimorphism, an absorption of sunlight and, in the case of pets, the elicitation of a protective response from humans (us). Now how is it that humans and animals, all mammals, differentiate in how the hair is actually presented on their bodies? Though humans are covered in hair completely, they are not covered to the extent that animals are. This is because mammal body hair is an evolutionary enigma.

The common belief of hair evolution is that hair evolved to help retain body heat since hair is an excellent heat insulator. But there is no conclusion as to which evolved first: hair or warm-bloodedness (endothermy). Researchers verbally combat between the two all the time. Most ‘Darwinists’ believe that humans evolved in Africa along with other primates, all of which were almost totally covered with thick fur (again, hair). As such, a common view is that now the body hair of men and women are purely vestigial, a useless evolutionary leftover from when we were ape-looking animals. Initially hair arose as surface insulation, retaining body heat in primitive mammalian endotherms.

The reason for the putative issue of human hair loss in evolution is still unknown, and all the explanations and reasoning proposed are contradicting.

Harrub, Ph.D. Brad "Why do Humans Lack the Abundant Hair of Apes?", Article. Web. 2003. Nov 2010.<https://www.apologeticspress.org/articles/2345>

“Human Thermoregulation and Hair Loss,” Article. Web. 2003. Nov 2010. <http://www.modernhumanorigins.com/>

Bergman, Ph.D. Jerry " Why Mammal Body Hair is an Evolutionary Enigma" Article. Web. 2004. Nov 2010. <http://www.creationresearch.org/crsq/articles/40/40_4/Bergman.htm>

The process of evolution depends greatly on the environment itself. While evolution is the change in a species over time, natural selection is the primary mechanism of change for evolution to occur. When natural selection happens, it determines what organisms are best adapted to the environment in order to survive and reproduce, passing on traits to the next generation. The organisms that pass off those traits withhold genes that are “fit” to comprise the next generation. The environment influences the genetic characteristics of an organism’s population, which changes over time.

Evolution can have three outcomes. The species can survive successfully in the environment and live on for a long time, undergoing few changes. In the second case natural selection may induce speciation, changing the older species into a new one or the third case in which, disruptive selection can occur. “A sudden shift in the environment such as a loss of habitat, a species may not been able to live long enough to reproduce. If this happens, then the species will become extinct, will die and be loss from Earth's future forever.” - Dr. Smith, from the University of San Diego

Ultimately, I’ve concluded that for the process of evolution, extinction is result of the cycle (of evolution) that is not suppose to happen. The primary goal of evolution of is to invoke change in a species so it is able to survive over time and when disruptive selection occurs the species may have a difficult time doing that, which can result in extinction. While extinction occurs in some species, I believe it is also a natural part of the evolution process that just happens. We always hear on the news about animals going extinct and how we should save the polar bears and what not, which makes sense. If there is something about the environment that humans are doing that is contributing to the extinction of these animals then it’s not natural, we should try to save the species. However, if a meteorite comes out of sky destroying all living things that’s just evolutions way of saying “Extinction Happens!” if you catch my drift. Either that or the gods are just really angry at us.

Sources

• http://www.globalchange.umich.edu/globalchange1/current/lectures/selection/selection.html
• http://www.starsandseas.com/SAS%20Evolution/SAS%20natselection/natselec_extinction.htm
• http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/Evolution.html
• http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_02
• http://www.pbs.org/wgbh/evolution/extinction/index.html

A study, led by Dr. John Hawks, has found that humans are evolving up to 100 times faster in the last 5000 years then they have been since we split with the ancestors of Chimps. The study has also found that humans are becoming more genetically diverse, depend on what part of the world they live in. such as the gene for lighter skin in northern Europe, or the African population becoming resistant to Malaria. Or how a majority of the Chinese and African population cannot digest lactose in milk, but a majority of Europeans have a lactose-tolerance gene. One reason could be that in northern Europe there is less sunlight and its lower in intensity, so people make less vitamin D in their skin. Vitamin D is critical for absorbing calcium, so people in Europe needed to be able to digest lactose to increase the amount of Vitamin D they have.

“Despite its tragic impact on the modern world (the overwhelming majority of mate battering and spousal murders worldwide is caused by jealous violence), jealousy very likely emerged around 3.5 million years ago in our hominid ancestors as evolutionary adaptive response of vital evolutionary value for both genders”, according to Jorge N. Ferrer. Jealousy provided as an evolutionary adaptation for males to assure paternity and to avoid spending resources on other male’s offspring. Furthermore, females use jealousy to guarantee protection and support for her offspring by having a steady partner. This might explain why men feel intense feelings of jealousy if they suspect their partner of sexual infidelity and why women feel intense jealousy when they suspect their partner of emotional attachment with someone else. Interestingly enough, this modern analysis provides a connection between “gender- specific jealousy” and jealousy as an evolutionary adaptation.

Moreover, a new study at University Of Portsmouth challenges the scientific belief that only humans and chimpanzee are able to experience “secondary emotions” such as jealousy, shame and pride. They found that dogs demonstrate human-like jealousy when another human or animal are brought in to make a “love triangle.” Scientists found that dogs get particularly jealous when their owner showed affection to an outside party. Scientist from the University reported dogs demonstrated jealousy 80 percent of the time.

            Additionally, according to evolutionary psychology, jealousy is a genetic instinct used to enable possessiveness. This allows monogamy to become possible. Jealousy is simply a defense mechanism that might naturally occur if the joy of his or her partner were to arise because of someone else. Polygamists (those who life an alternative lifestyle where a man may have more than one spouse) commonly dismiss their natural instincts. For example, the Kerista community of San Franisco has coined the term “compersion” which is said to be a “non-sexual state of empathetic happiness and joy experienced when an individual's romantic partner experiences happiness and joy through an outside source, including, but not limited to, another romantic interest.”

Citations

Ferrer, Jorge N.. "Monogamy, Polyamory, and Beyond." Tikkun 22.1 (2007): 37-43, 60-2. OmniFile Full Text Mega. Web. 28 Oct. 2010.

http://www.google.com/search?sclient=psy&hl=en&safe=active&client=firefox-a&hs=zIX&rls=org.mozilla%3Aen-US%3Aofficial&source=hp&q=define%3A+compersion&aq=f&aqi=&aql=f&oq=&gs_rfai=&pbx=1

http://www.physorg.com/news75357071.html

The most complicated object in the known universe is the human brain. On average, our brain contains about eleven billion neurons. Each one working to send, receive and process electrochemical signals. Our thoughts, emotions, movements and very existence are dependent on processes within the brain that are still largely a mystery to us. One may wonder how such a wondrous and complex organ came to be. It is here that we begin to decipher the effect of evolution on the human brain.

Assuming the theory of evolution, that organisms more suited to their environment can survive better and mate, it makes sense that, somehow, having a larger and more complex brain makes survival on Earth easier. Indeed, if one were to look at the brain size of our hominid ancestors from four million years ago, it would be discovered that their brains were a mere 400 grams. Compare that to the present size- over 1400 grams (1.4kg).

But it was more than sheer size that changed, but the actual structure of the brain. What happened earliest was the centralization of the brain’s nerve cells. What started as a loose and messy grouping of cells that would be seen in a jellyfish, turned into a spinal column and enlarged fore- and hindbrain. These parts of the brain that are relatively new are known as neocortical, literally “new brain”. Actually, things such as our abilities to speak, plan, and be conscious of our own existence depend on neocortical structures. This means that when the brain became more complex, we gained a completely different way to interact with our world. Language allowed humans to organize themselves and hunt more effectively- and having a larger and more complex brain allowed a higher capacity for intelligence, thought, and planning. These are all things that gave humanity an advantage against predators, prey, and the world’s wide variety of dangerous natural elements.

The brain also experienced a phenomenon known as encephalization, which is the concentration of sense organs and neurons in one part of the body. This is why the brain, olfactory sense, hearing, and sight are all housed in the head. This made it easier for the brain to work because the signals that neurons use wouldn’t have to travel as far if the brain is all in one place.

Evolution caused the brain to become larger, more complex, and more efficient. Much how we make our computers with more space, more speed and efficiency with every new generation (this excludes Apple, of course). There is certainly is proof of our brain’s effect on the world. Humans are definitely a thriving species. One may also consider the worldwide subjugation and abuse of animals to be proof of our dominance as a species.

But it is important to remember that neurology has only scratched the surface when it comes to the human brain. There are still plenty of things we don’t know, actually we don’t know most things. There could be all kinds of secrets within the brain waiting to be unlocked, like other senses, the power of thought, or ways to become more intelligent faster. All this would also make one wonder what evolutionary stage the brain will achieve in another thousand years.

Works Cited:

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