Chalk up my Life
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.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:
ScienceDaily completed a long-term experiment that explains all of these traits. They did a study of the same people and their children over the course of 60 years. Their conclusions showed that humans are still evolving, and children are becoming shorter and heavier.
Humans are still evolving, but how fast are things changing? “The changes may be slow and gradual, but the predicted rates of change are no different from those observed elsewhere in nature, the researchers say.” Humans aren’t going to be extinct anytime soon, but we will be eventually. The more technology we have, the less we rely on natural selection.