Week 8

1.         Overexposure of solar radiation can cause the skin to burn and can also cause damage to DNA. High levels of solar radiation can lead to genetic mutations in skin cells which can lead to skin cancer and if left untreated can spread to other organs and cause death.

UV radiation also rapidly depletes serum foliate levels in light skinned individuals. This affects pregnant women and can cause spina bifida of babies. The breakdown in B vitamins can also cause anemia.

2. 

High Levels of Solar radiation: Short Term. We do not have a short term adaptation. When exposed to too much solar radiation, the skin burns.

 High Levels of Solar radiation: Facultative. An example of facultative adaption is tanning.  Tanning is an example of acclimatization because it is a temporary and rapid adjustment.  The tan is temporary and the skin will return back to its original skin tone after sun exposure has been reduced or stopped.

 



High Levels of Solar radiation: Developmental. Long term adaptations in humans include deeply pigmented skin. If individuals are born with dark skin it will not get lighter if they are never exposed to sunlight. Skin color is affected by melanin. Melanin is extremely important as it acts as a built in sunscreen because it absorbs potentially dangerous ultraviolet rays.  Melanin protects us from overexposure to UV radiation. Light skin produces small amounts of melanin.  Deeply pigmented skin produces maximum levels of melanin.  Individuals that have darker skin have higher exposure to solar radiation. They tend to live in warmer climates. Over time, they produce more melanin which protects them. Individuals that live in northern areas are usually colder so these individuals wear more clothing that helps block the UV exposure and protect their fair skin.

High Levels of Solar radiation: Cultural. There are numerous cultural adaptions to solar radiation.  Shelter, shade, clothing, and sunscreen provide protection from solar radiation.  Individuals can wear clothing with UV protection, hats, sunglasses, carry umbrellas and wear sunscreen.  Although sunscreen will not protect the skin for a long period of time or

protect it completely, it will let the individual spend more time outside in the sun to work or enjoy recreational activities without causing damage.

3.         The benefit of studying human variation across environmental clines is to see how humans adapt to environmental influences.  If we studied only one environment we would not be able to see the impacts of solar radiation.  We would only have data from one source instead of multiple clines. As an example, if we studied solar radiation and skin color for individuals living near the equator, we would get different data than if we studied individuals that live in Alaska. Those that live near the equator have darker skin and higher tolerance to solar radiation than those that live north and are light skinned.  Being able to study the variation across environmental clines helps us understand solar radiation affects.  There are positive and negative affects of solar radiation which include skin cancer or on the flip slide, the lack of solar radiation can cause lack of Vitamin D which can cause anemia, rickets disease and even osteoporosis.

4.         We could use race to help understand the variation of adaptions of solar radiation.    Characteristics of skin color, hair color, and eye color could help us understand the over or under exposure of the solar radiation.   It would be helpful to include the environmental influences as well and study how these individuals adapted to their environment.

Week 7 Language

            I found the experiment difficult as it was hard to hold a conversation with my daughter and husband when I was unable to speak but they could.  As they spoke to each other I disagreed with what they were saying.  Nodding my head “no” and adding hand gestures were not difficult, however, it was difficult for me to communicate what I wanted to say. At first they tried to figure out what I was trying to convey but after some time they seemed annoyed and mostly talked to each other.  I tried to jump in the conversation but their conversation moved quickly and I sat there trying to figure out how to gesture my input without using spoken words.

            My partners in the experiment said it was hard to communicate with me.  When I was gesturing, they did stop talking and looked at me.   Although they did try to figure out what I was saying I was not successful in getting my point across.  I could clearly understand their words but they had trouble understanding me.  I wanted my daughter to tell her dad about cheer practice and how they learned a new stunt.  It was pretty much impossible for me to communicate that as it was complex and beyond the simple gestures of “no”, “stop”, “eat”, “drink”, and “look”.

            The culture that uses symbolic language clearly has the advantage in explaining complex ideas.  They can quickly respond to each other with little effort unlike a culture that does not use symbolic language. I noticed that my partners became impatient with me as they could not understand what I was trying to convey.  They eventually kept their own conversation going and although I tried, I was unable to really be part of what they were saying.

             Individuals that have difficulty with communication could be individuals that know little English or English is not their first language.  Tourists and recent immigrants could have trouble communicating.  Although these individuals may know some English words they might use the wrong words or they may not pronounce the word correctly so it is hard to be understood.  I have some co-workers whose first language is not English.    I have a difficult time understanding them and they ask me to speak slowly when we are talking.  When speaking to them I also try to use basic words in hopes they understand what I am saying.  This takes patience on my part and on their part.

 

Part 2:

            We did the experiment for 15 minutes, however, I was not able to last the full 15 minutes without raising my eyebrow.  I apparently raise my eyebrow much more often than I ever thought.  My daughter really enjoyed watching me and waiting for me to move.  It was a challenge to keep my voice at an even tone and not make any facial movements, but at least I could join the conversation!  Holding a conversation and not being able to show any type of emotion or movement in relation to your conversation is difficult but less difficult than the first experiment. During the second experiment I was able to use words and ask my daughter about cheerleading. However, not using voice inflections was difficult when I responded to her.  I felt like a computer and sounded like Siri.

            My husband thought that listening to me speak in an even tone was like reading a text or email.  The conversation had no emotion. My daughter on the other hand completely enjoyed the experiment.

            Voice inflections, eye contact, and hand gestures play an important part in our communication.  Our society relies heavily on emails and text messages and often I see misunderstandings occur from this type of communication.  These emails and text messages can come across harsh. Without the human emotion and body language there are misunderstandings that occur.      

            Body language is very relevant to all aspects of our lives.  It plays an important part in our personal lives with our families and friends as well as business lives and careers. For example, my daughter may say “Okay” but she rolls her eyes when she says it. To me the word “okay” is an agreement that I was heard and she agrees to do what I asked, but when she rolls her eyes when she answers then it means she is annoyed and not being sincere.  Another example would be a face-to-face meeting versus a conference call at work.  A face-to-face meeting is always more beneficial than a conference call as the body language and facial expression can be seen. On a conference call the parties rely only on words and vocal tones and the parties cannot see the facial expressions of either excitement or disapproval.

            A scenario where I can imagine that body language would not be a benefit would be if you are doing a job interview and you are nervous. Instead of showing confidence you are showing that you are nervous and uncertain and do not make good eye contact.

In conclusion, body language is very important as it promotes clearer communication in our everyday lives.

Piltdown Hoax

            In 1912 near the village of Piltdown located in southeast England, an amateur geologist, Charles Dawson, discovered skull fragments that he believed was from a human ancestor.  Renowned English geologist Sir Arthur Smith Woodward from the Natural History Museum in London joined Dawson on his dig and hoped to discover more fossils during the summer dig.  They found Stone Age tools, animal fossils, and an ape-like jawbone with teeth similar to human teeth.  This was a huge discovery as it connected humans with apes which supported Charles Darwin’s theory. This discovery came at a time when British scientists were desperate to find evidence to support Charles Darwin’s theory of evolution.  Germany and France scientists had already discovered fossil ancestors and British scientists were eager to do the same. Sir Arthur Keith, England’s leading anatomist embraced this discovery as it validated his theory of human evolution. He believed that early humans developed big brains before they walked upright.  Scientists now know that the opposite is true. Humans developed big brains after walking upright.

            The Piltdown Man was believed to be about 1 million year old which made it the oldest human ancestor thus far discovered.  In December 1912 at the Royal Geological Society, Woodward made their first public announcement of their discovery.  Paleo-anthropologists worldwide were enthusiastic about this discovery.  The news of Piltdown Man spread around the world from Europe to America, Africa and even to Australia.  Some experts had their doubts that the jawbone and skull were from the same creature.  The articulation bone was broken off so there was no way to see if the jawbone was a true match to the skull.  Over the next couple years Dawson and Woodward made more discoveries including a canine tooth, skull pieces, and another molar tooth.  These findings silenced the skeptics, at least publically.

            During the 1920s and 1930s ancient remains were discovered but these fossils did not align with the Piltdown Man. In 1924, Raymond Dart discovered a skull of an ape-man but its brain was smaller in comparison to the Piltdown so British scientists were not convinced that it was a human ancestor.  

            In the 1940s new technology was developed for dating fossils and in 1949 the Piltdown fossils were tested using the fluorine analysis.  It was determined that the fossils were not 1 million years old but were about 100,000 years old.  In 1953, the Piltdown fossils were retested with better dating methods and a microscope and scientists proved that the jaw was from a female orangutan and was 100 years old.  It was also discovered the teeth were filed down and had been boiled and stained.

            The human faults that came into play during the Piltdown Hoax were the need and desperation of England to discover primitive humans in their country.  Other countries were making discoveries but England was not. This had a negative impact on the Piltdown process. In addition, the Natural History Museum allowed very few to examine the Piltdown fossils.  The fossils were not subjected to a wide study and had they been, I believe the hoax would have been exposed much earlier. 

 

            Today we have new processes for dating fossils which includes fluorine analysis and various chronometric techniques based on radioactive decay. Potassium-40 is widely used by paleoanthropologists to data fossils in the 1 to 5 million year range. Scientists today have numerous tools and tests available but the human factor is still used in the interruption of the tests results and the human factor is used to theorize.

             The fossils that were discovered that did not align with the Piltdown Man should have been examined more thoroughly. However, anything that contradicted the Piltdown fossils at that time were under high scrutiny and dismissed.  A lesson learned from this historical event is that the evidence should be examined by multiple sources even when the discovery is made by someone that is highly respected. The evidence should be studied and analyzed by a group of peers before being dismissed.

 

 

Week 4

Lemurs are found on the island of Madagascar and the Comoro Islands which are located about 250 miles off the Southeast coast of Africa in the Indian Ocean.  The climate of this area ranges from tropical to arid. Lemurs live in all areas of these islands and adapt to their environment but you can find more lemurs in the forests as more food is available.  They live in trees and eat a variety of food for survival.  They mostly eat nuts and fruit but they also eat flowers, sap, tree bark and flowers. Lemurs spend much of their time in the trees but do spend time on the ground as well. 

The dentition pattern of Lemurs is 2-1-3-3 (incisors, canine, premolars, molars). Their incisors and canines are procumbent (face forward) which provides a tool for grooming or feeding such as removing large seeds from fruits.  Their teeth can also cut through bark which enables them to eat the sap.  Their teeth have adapted to the current state so that they can crush seeds and cut through bark.

 

 Spider Monkey

Spider monkeys live in the rain forests of Central and South America and some also live in Mexico.  The spider monkeys look for areas that offer a protective canopy of trees.  Spider Monkeys play a very important role in their habitat as they spread seeds from fruits, plants and flowers which help new vegetation grow.  They forage for their food high in the trees (80 feet – 100 feet high) and they mainly eat fruits but will also eat nuts, bird eggs, spiders, and leaves which they find in the treetops.   

 

The dentition pattern of a spider monkey is 2-1-3-3.  Their sharp teeth help them bite through the hard seeds.

Baboon

Baboons live in Africa and Arabia.  Most of them live in semi-arid environments and tropical forests. They need to live near a water source and seek the protection of tall trees or the cliff faces.  They spend most of their time on the ground but do climb trees to eat and sheep.  They eat fruit, seeds, bark, grass, roots, birds, sheep and even antelopes.

They have very long canine teeth and strong jaws which allow them to be a predator and eat other animals such as sheep.  The dentition pattern of a baboon is 2-1-2-3.

 

 
Gibbon

Gibbons are found in the rain forests of southern Asia. They spend almost all of their lives in the treetops and rarely descend to the ground.  They mostly eat fruit but will eat leaves, insects, tree bark and flowers.  They will sometimes eat birds, bird eggs, tree frogs and insects.

The dentition pattern of a gibbon is 2-1-2-3. They large canine teeth help them rip bark from the trees.

 

Chimpanzee

Chimpanzees live mostly in rain forests but some live in wet savannas of Uganda and Tanzania. Chimpanzees spend their time in trees and on land. They sleep in trees and also scavenge for food in the trees.  The diet of chimpanzees consists of fruit, seeds, insects, and eggs and they will kill and eat birds and even antelope.    

The dentition pattern of a chimpanzee is 2-1-2-3.  Chimpanzees have 32 adult teeth which are the same number as humans.  The upper jaw of chimps is u-shaped.  Their canine teeth are large and pointed.  Chimpanzees don’t need the large canine teeth to eat fruit and leaves but these large teeth could also be used as a threat against enemies.

 

Summary:

Lemurs and spider monkeys share the same pattern of 2-1-3-3.  They have sharp canine teeth due to their diet of mostly bugs.  They are arboreal and over the course of evolution these primates have adapted their diet.

 

Baboons, gibbons, and chimpanzees share the pattern of 2-1-2-3. They eat a variety food including small animals so their large canines allow them to tear their food.  These large canines are very visible and could also be used for intimidation against predators and their prey.  These primates are Omnivore (an animal that eats both plants and animals).  Over the course of evolution this led to the change in their dentition.

Week3

Homologous traits are those that are inherited from a common ancestor. 

 

Berkshire pigs and bobcats share the homologous trait of having four legs.  Berkshire pigs have firm bodies with short legs.  Berkshire pigs are black with white on their legs, face and tail.  Their dark skin keeps them from being sunburned. The Berkshire pigs are medium sized animals and weigh around 600 lbs.

 

Berkshire pigs were brought to the United States in 1823.   These pigs produce high quality meat and are known for its texture, tenderness and juiciness. 

 

Bobcats grow up to be about 41 inches long and weigh about 25 lbs.  They live about 12 years.  Bobcats are carnivores and eat small animals such as squirrels, birds, mice, and rabbits. They hunt deer, sheep, and even young pigs.

 

The Berkshire pig uses his four legs to stand and walk.  Pigs often have structural unsoundness of their legs which include buckling of the knees, bowed legs, swollen joints and general lack of freedom in movement. The Berkshire pig moves slowly in comparison to the bobcat. Bobcats use their legs to stand, walk, run, and balance themselves.  They are agile and climb well. They are also excellent swimmers and hunters.   The legs of the bobcat are long and lean which give them power for jumping and running.  Bobcats hunt for their food in comparison to pigs which are raised on farms and fed fresh vegetables. 

 

              

 

 

Both bobcats and pigs are mammals. They both are warm blooded vertebrate animals. They breathe air with their lungs.  Pigs are part of the biological family of suidae (hogs and pigs) and bobcats are from the biological family of felidae (cat family).

 

 

 

PART 2

 

Birds and butterflies share the analogous trait of wings.  Birds have two wings and in comparison butterflies have 4 wings (2 large and 2 small).  Although they both have wings they are very different species.

 Butterflies are insects and have a head, thorax and abdomen.  They have 3 pairs of walking legs (6 jointed legs), an antennae, spherical compound eyes, and an exoskeleton. Each spherical compound eye comprise of 17,000 individual light receptors with their own microscopic lenses. Butterflies are anthropods.  Their exoskeleton is a shell-like skin to protect their internal organ but it does not grow.  Occasionally it must be shed.

 Birds on the other have two legs, a beak, and four color receptors in their eyes so they can see ultraviolet light.  The body of birds are covered with feathers. Birds have an internal skeleton with bones such as ribs, a skull, and femur.

The evolution of birds is thought to have begun during the Jurassic Period from a clade of theropoda and butterflies/insects appeared on Earth about 300 million years ago and evolved from Trichoptera.  It is thought that the butterfly and the bird’s common ancestor is a reptile which did not have wings.

 

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Darwin Assignment

1.          I feel that Thomas Malthus had the most positive influence over Darwin’s development of his theory of natural selection. Thomas Robert Malthus, was an 18^th century economist and a clergyman at the Church of England.  In 1798, Malthus published, Essay on the Principle of Population. The essay described that the human population will grow in areas that have plenty of food and resources and areas that have less resources will struggle to survive. Populations will outgrow food and resources available which will lead to starvation and poverty unless people exercise restraint.

After reading Malthus’ essay, Charles Darwin realized that much of his own research of nature resembled Malthus’ description of human population.  Darwin realized that the growth population or lack there of applied to not only humans but also to nature.  He saw competition between individual species.  For example, a bird with a sharper beak may have a better chance of survival or reproduction.  Therefore, the struggle to survive or the survival of the fittest as applied to nature helped Darwin shape his ideas for the Natural Selection.

2.    Thomas Malthus contributed to the scientific community by observing the growth in population and how it relates to hunger, disease, struggle and survival.  He also observed the population of animal and plants and studied how they produce offspring.  Malthus is best remembered for his influence and contribution to Charles Darwins theory of natural selection. http://evolution.berkeley.edu/evolibrary/article/history_07

 

3.       Thomas Malthus most directly affected the following point:    Resources are limited.

Malthus Essay on the Principle of Population focused on population growth, resources, and the natural outcome from these influences.  Without the proper resources there will be a struggle to survive.  These theories influenced Darwin’s work. In Darwin’s natural selection demonstrates that resources are limited.

4.       Could Darwin have developed his theory of natural selection without the influence of Thomas Malthus?

The following quote is from Charles Darwin’s autobiography (1876), “In October 1838, that is, fifteen months after I had begun my systematic inquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long- continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The results of this would be the formation of a new species. Here, then I had at last got a theory by which to work".

This quote clearly states that Malthus’ Essay on the Principle of Population (1798) was crucial  to Darwin’s theory of natural selection.  I do not believe he would have come up with his theory without this viewpoint from Malthus.

5.       How did the attitude of the church affect Darwin and his eventual publication of his book on the Origin of Species?

           Religion was very powerful in the early nineteenth century Britain.  The church was heavily connected politically and socially. Darwin was social and while living in London he rubbed shoulders with affluent and influential scientists.   Darwin attended church regularly and his wife was very religious.  His theory undermined the Christian belief and he knew it would get negative response. The church had a big influence on Darwin as he was very reluctant to publish his theory in fear of repercussions for himself and his family.  Darwin waited  20 years to publish his Origin of Species and he only decided to publish it after he received a paper from Alfred Wallace whose paper stated the same theory his own.  Darwin knew if he didn’t publish his book soon then he would receive credit.