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Life of Cannibalism

Posted by Kimberlea Talington in Science and Society - Best on Tuesday, November 16, 2010 at 9:47 am

Many people around the world have heard of cannibalism, the act of consuming another of the same species. It is frowned upon in mostly every part of the world, yet in the animal kingdom it is seen as a part of nature.

There are 4 different “types” of cannibalism. The most common in the animal world is Sexual Cannibalism, in the female of a species mates and then eats the male of the same species. The next is size structured, in which the strongest and the biggest will eat the weakest and smallest. After that would be cannibalistic infanticide, which is when the mother will eat the weakest of her young. Last is Intrauterine cannibalism which takes place in the womb. It’s when strong embryos will “eat” the weaker for nourishment.

This could have a number of different reasons. Sexual Cannibalism’s reason could be to make sure that each creature only has one mate. Because  the female wants only he r children to be the strongest so by mating with the strongest male and then eating him, she insures that. cannibalistic infanticide could have a lot of reasons. One could be to make sure that there are no “flaws” in the species, but eating the weakest or “flawed” baby. It could also just be another way of getting food. If the mother eats her flawed weak child, then it will give her the nutrition she will need to feed the rest of her young.
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How does the history of evolution predict the outcome of future evolution?

Posted by Charles Labb in Science and Society - Best on Monday, November 15, 2010 at 7:19 pm

The history of evolution shows us that when there is a pressure change that threatened the survival of an organism, the organism evolves to continue living.  That shows us that for future evolution, for example, homo sapiens might start to have more and more hair due to the recent climate change and issues of global warming, so they can continue to live and keep warm throughout the decades to come.  If the world where to become flooded, leaving very little land but enough for people to migrate and find new sources for food and shelter etc., then we would have to find another alternative to the way we live now. If people had to swim from point A to B, I don’t think that we would necessarily grow gills, but I do think that our lungs would grow larger and bigger. If you were to look at a mammal that lives in the water, such as a dolphin, whale, or sea lion, they do not have gills. They need to resurface from time to time to get oxygen. So, if  the world did start to flood you could only imagine that people would start to hold their breath longer and probably have webbed fingers and toes to help swim in the water.

I don’t think that evolution can be determined by looking at history and seeing what has happened.  I believe to see the future in evolution you have to look to the present and see what is happening now in front of you.  If there are no selection pressures maybe evolution will just start to get rid of what we don’t need, like the pinky toe or the male nipple.  The problem with the theory of evolution is that there is nowhere near enough data to say this is how evolution works.  The reason being for that, even though evolution is amazing on its own, it takes centuries for it to occur. 

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Sexual Reproduction Vs. Asexual Reproduction

Posted by Robert Nurse in Science and Society - Best on Monday, November 15, 2010 at 11:23 am

Asexual reproduction is a form of reproduction, which only involves one parent. Plants for example use asexual reproduction or in their case vegetative reproduction. Vegetative reproduction is when parts of the old plant fall off and develop into new plants. The new plants will grow very close to each other and to the parent. This will cause a struggle for soil, nutrients and light, and will consequently cause the plants to be less healthy. During asexual reproduction there is no chance of an evolution occurring, the offspring would almost always be of the same species and would be identical to the parents, so diseases are also passed down directly from the parents to the offspring.

Sexual reproduction is reproduction involving the union or fusion of a male and a female gamete. During sexual reproduction is that there is a large chance of an evolution-taking place. The new species will be able to adapt to environmental conditions, and the new character that is formed with the mixed gametes of the parents so there is a chance that the parent’s diseases would not be received by the offspring.

Sexual reproduction is important when talking about evolution because it also facilitates the increase in fitness under natural selection, leading to the 'best' combinations of genes. Sex can impede the increase in the fitness of the population the how it can remain the dominant form of reproduction across all manner of species. Sex at its foundation of merging of genes from different individuals creates genetically unique genes. If the goal is to maximize fitness by finding a particularly good combination of genes, asexual reproduction - which increases a population's numbers at a much faster rate than sexual reproduction works pretty well. 

University of Iowa. "Value of Sexual Reproduction Versus Asexual Reproduction." ScienceDaily, 25 January 2010. Web. 15 November 2010. http://www.sciencedaily.com/releases/2010/01/100121161238.html

Ridley, Matt. "The Advantages of Sex." 4 December 1993, Print. http://www.pbs.org/wgbh/evolution/sex/advantage/index.html

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How Becoming Carnivores Changed the Evolution of Humans

Posted by Marchella Baldwin in Science and Society - Best on Sunday, November 14, 2010 at 5:39 pm

How did meat eating begin?

Meat eating has been said to go as far back as 2.5 million years for humans. Fossils of tools used to butcher meat are found to have gone back that far. It is believed that we started eating meat because of the competition for food between other species. Craig B. Stanford points to an example of this in the Bwindi Impenetrable Forest National Park. This forest is the only forest where mountain gorillas and chimps live together. Chimps eat meat while Gorillas don’t meaning that they can coexist together because they have two different diets.

 How meat eating affected the evolution of humans

Long ago when humans started to eat meat it triggered tons of evolutionary changes. For one thing, our jaws have gotten smaller so we can chew meat better. And because of our diets being chocked full of meat we have evolved to have an improved ability to process cholesterol and fat.  Also, scientist say that eating meat helped our brains to grow bigger and our figure slimmer. All these positives from meat though did not happen until we started cooking meat. To get the caloric energy you get from meat you have to cook it. So we really didn’t start reaping the benefits of meat until we discovered fire.

Being a meat eater isn't all positive

But everything that has evolved from meat eating was not good. Because our jaws are downsized are teeth cannot fit inside. So it’s rare to find someone who has perfectly straight teeth that did not have any dental work on them. Also us evolving to cooking and using forks and knives has made out big teeth useless because our food is so soft. 

Sources:

Mayell, H. (2005, February 18). "evolving to eat mush": how meat changed our bodies. Retrieved from http://news.nationalgeographic.com/news/2005/02/0218_050218_human_diet.htm

Joyce, C. (Producer). (2010, August 2). Food for thought: meat-based diet made us smarter [Audio Podcast]. NPR Series: The Human Edge. Retrieved from http://www.npr.org/templates/story/story.php?storyId=128849908

This picture from left is of castings of teeth from a chimpanzee, Australopithecus afarensis and a modern human

dentition_custom
dentition_custom
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The Future of Human Evolution

Posted by Alexis Montgomery in Science and Society - Best on Sunday, November 14, 2010 at 8:15 am

It is no easy task to predict what the future of the human race will be. According to US News, “Humans are evolving faster than ever before, picking up new genetic traits and talents that may help us survive a turbulent future.” The human race, which is a quite intelligent, evolves everyday. Until recently scientists believed that the human evolution had slowed down, due to the lack of visual changes, failing to look deeper into the issue. Human are now evolving within their genomes and DNA, it has been scientifically inferred that with so many changes within the human body as opposed to the physical features, will one day start to change humans outer body.

A recent study in the news, (available on livescience.com) shows that speculation that changes in human mating patterns may be contributing to the increase in autism. Others track how humans have morphed in response to changing circumstances, including enhanced abilities to metabolize sugar and fight disease. One of the biggest changes within human DNA is that some humans are becoming more resistant to the HIV virus and it will become more common in the future, as well as changes in human body makeup. One of the factors of that is that it a new form of DNA testing helps parents choose the genetic makeup of their children, rejecting embryos with inherited flaws or embracing those with desired traits—such as being the right sex. The future of human evolution is based on the future of new testing techniques.

Sorry this is late, I thought I uploaded, but didn't...

Tags: scisocY
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Mental Disorders.

Posted by Mary Altamuro in Science and Society - Best on Saturday, November 13, 2010 at 6:51 pm

Mary Altamuro

 

When we think of the mentally handicapped or those with mental disorders, we instantly feel pity.  We usually do not stop to wonder why or how a person came to be stricken with the disability or disorder that afflicts them.   I find myself curious about why these disorders still exist generation after generation even after all the scientific effort at uncovering the causes and possible cures.  A great deal of time and attention has been spent on how these disorders came to exist and what might make them worse and how to make them better, but there is still so much we still need to learn.  Thankfully, scientists have given us a great deal of information that can be very beneficial in understanding, treating and hopefully someday curing or preventing mental and emotional issues. 

Recently, studies have shown that a genetic predisposition may be hidden in people that makes them prone to certain characteristics that when provoked, can create emotional or mental conditions.  This predisposition, in conjunction with a triggering event or simply by the quality in that person’s environment and upbringing can cause these characteristics to become problematic and spark a mental or emotional abnormality. This peculiar phenomenon is called the diathesis-stress model.

According to this theory, when provoked, a characteristic may go into overdrive, causing a person to have a legitimately diagnosable illness. Environmental stimuli that may cause such a thing to happen are social issues or trauma that may have occurred at a young age.

 One of the most common problems that can cause such a change in people would have to do with their parents. If a young person does not receive the right kind of attention as they are maturing, it can cause emotional and social problems for them later in life.  An overbearing or judgmental parental figure can cause a person to have low self-esteem, which could then inflict disorders such as narcissistic personality disorder, social anxiety disorder or even depression.   Parents who get divorced have also been shown to cause obsessive-compulsive disorder in as children of divorced parents tend to feel they have a loss of control in their lives and obsessive-compulsive disorder is a disorder driven by a person’s overwhelming need and drive for control. 

These disorders reveal themselves when people who are predisposed for the characteristics are triggered by an emotional or social stress. This ignites an inner need to balance themselves out, mentally. Sadly, they often emotionally overcompensate; leaving them worse off then they were in the beginning.





Sources:

The Cleveland Clinic Foundation, Initials. (2005, May 20). Narcissistic personality disorder. Retrieved from http://my.clevelandclinic.org/disorders/personality_disorders/hic_narcissistic_personality_disorder.aspx


Elana Pearl Ben-Joseph, MD, Initials. (2008, November). What causes ocd?. Retrieved from http://kidshealth.org/teen/your_mind/mental_health/ocd.html#


Amal Chakraburtty, MD, Initials. (2010, March 01). Causes of depression. Retrieved from http://www.webmd.com/depression/guide/causes-depression


Rashmi Nemade, Ph.D., Natalie Staats Reiss, Ph.D., and Mark Dombeck, Ph.D., Initials. (2007, September 19). Current understandings of major depression - diathesis-stress model. Retrieved from http://www.mentalhelp.net/poc/view_doc.php?type=doc&id=12998&cn=5


Cadena, Christine. (2007, November 16). How anxiety develops in children: the "diathesis-stress" model. Retrieved from http://www.associatedcontent.com/article/446920/how_anxiety_develops_in_children_the.html
Tags: scisocY, Best, evolution
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Research Question: Like other initially controversial scientific theories, will evolution one day be universally accepted by society?

Posted by Yousef Ahmed-Serir in Science and Society - Best on Friday, November 12, 2010 at 8:27 pm

Research Question: Like other initially controversial scientific theories, will evolution one day be universally accepted by society?

Evolution has been a controversial theory since the first day word reached out about it. But, this is not unlike many other theories which we consider true and indisputable today. For example, Copernicus' Heliocentric theory and Newton's gravitational theory. Copernicus' Heliocentric theory basically asserted that the earth was not the center of the solar system, but the sun. At the time, everyone believed in geocentric theory which said that the earth was the center of the universe. This theory was so novel and unprecedented, people were quick to scorn Copernicus and dismiss the theory as nonsense. The dissension around it did not end for later Galileo defended it. He was a supporter of Copernicus and was put on trial by the Catholic Church for defending something that they felt contradicted religion.They wanted the theory banned. This is almost the exact same scenario with evolution today. The Copernican theory gained legitimacy over time and became universally accepted. Newton's theory of gravity had similarly controversial beginnings yet no one contests it's admissibility today.


 If history has taught us anything, it's although initially controversial, theories with strong foundations such as Evolution do become universally accepted over time. There is evidence of evolution gaining more support today. Although just 39% of Americans believe in evolution, as indicated by a Gallup poll in 2009, that number has been on the rise, especially with the newer generations. 74% of people with a post graduate degree believe in evolution. There are some creationist museums today that include evolution in their displays. Perhaps one day even religious people can believe in the basic concepts of evolution while still holding faith in their religion at the same time. With the number of people who believe in evolution on the rise with newer generations, it is safe to assume that we will one day live in a society which almost unanimously accepts evolution as true. 

Sources: 
http://en.wikipedia.org/wiki/Heliocentrism
http://en.wikipedia.org/wiki/Nicolaus_Copernicus
http://en.wikipedia.org/wiki/Galileo_Galilei
http://firstread.msnbc.msn.com/_news/2009/02/12/4427408-poll-just-39-believe-in-evolution
http://tierneylab.blogs.nytimes.com/2009/06/30/creationism-evolution/

Tags: scisocY
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The Thumb

Posted by Andrew Smith in Science and Society - Best on Friday, November 12, 2010 at 2:26 pm

Andrew Smith The thumb

 

       The thumb is arguably the best adaptation humans have. We don’t think about it, and we take if for granted, but the thumb is used everyday, and makes things so much easier. However we didn’t always have thumbs, nor are we the only ones who have them. The first actual record of a thumb, was back when the Dinosaurs roamed the Earth, the most known is probably the iguanodon. So thumbs have been around for a long time, even sauropods that walked on all 4 legs seemed to have some resemblance in their feet to a thumb bone, But what about with humans?

One of the earliest apes (even before the Humans) that had a thumb was called the Proconsul; This ape lived around 17-23 Million years ago, Although not human, they evolved from the same  relative (The

Kenyapithecus) they are one of the first mammals on record to have a thumb. The first humans ever were the Homo habilis, they too had a thumb. 

            This all just means the thumb is a hard evolutionary trait to trace, they appeared way before humans and apes, but did not appear to be used as an opposable thumb until the first mammals.  Now here are some pictures of animals with thumbs:



https://docs.google.com/document/pub?id=1aGRxhoUyjJzfjckBhehzwz2vIjYCDi7MuhqcoAKhK5g
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Are evolution and "survival of the fittest" the same thing?

Posted by Amirah Burkett in Science and Society - Best on Friday, November 12, 2010 at 2:10 pm

"Survival of the fittest" is a term coined by Charles Darwin. Throughout Darwin's life he studied the evolution of animals but he is most known from his work with birds on Galapagos Island. What separates the two is survival of the fittest is a "race" between the same species of animals where only those who are capable of surviving the conditions presented to them. The Ginkgo tree, a native of Asia, was in a race with its own kind. When forced to survive in extreme conditions, the tree with the defensive adaptations survived where as the only thing left of the other variety of tree is a mere fossil. Evolution is the process to adapt to the conditions provided. The difference between evolution and "survival of the fittest" is that "survival of the fittest" is when one species is competing with itself with different varieties. Evolution is when one species is constantly changing to better survive in their environment.
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Why do we have opposable thumbs

Posted by James Seward in Science and Society - Best on Friday, November 12, 2010 at 12:49 pm

thumbs_up






For generations, humans have had the competitive edge over other species on this earth because of one amazing feature we have that other creatures don’t.  Our opposable thumbs.  We have these amazing appendages and we use them to do things most other creatures couldn’t even begin understand.  For those of you who don’t know, “an opposable thumb is a physical adaptation. An adaptation is a feature that helps a plant or animal survive in its habitat. Adaptations can either be physical (a part of the body) or a behavior an organism has developed.” Thumbs have helped us with things we normally could never do.  They let us hold things, make tools to work and work those tools.  They even let us give thumbs up.  They do so much for us that we sometimes even forget how important they are.  Years of evolution have let us go this far with thumbs and they will not stop now. 

 

 

Sources

http://www3.nsta.org/main/news/stories/science_and_children.php?news_story_ID=49036

http://www.wordiq.com/definition/Opposable_thumb

 

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