Human Variation & Race Blog

The environmental stress that I chose is high altitudes. High altitudes disturb our homeostasis in several ways including:

• ·         Respiratory conditions (i.e. hyperventilation, and respiratory alkalosis)
• ·         Increase in Pulmonary Artery Disease (due to strain on the heart as it pumps harder in an effort to oxygenate the blood
• ·         Intense UV Radiation

Some additional long-term effects of living at high altitudes vary based on gender and include the following:

• ·         Lower birth weight in infants
• ·         Delayed menstruation in women
• ·         Sterility in men

The major factor in the physiological changes resulting from living at high altitudes has to do with the lack of oxygen available. The body generally adapts to oxygenation levels at low altitudes and undergoes significant changes when forced to adapt to abnormal levels. Some of the complications that result from a severe lack of oxygen (known as hypoxia) include: fatigue, dizziness, headaches, body pain, ear-ringing, swelling and blistering of the hands and feet. More serious conditions include: swelling of the brain, fluid build in the lungs, and in some cases heart attack and stroke.

In cases where the body is required to adapt to these conditions in the short-term the changes it undergoes are not easy to detect and happen internally. Some of these changes include increased breathing, increased heart rates and blood pressure as the body attempts to compensate for the lack of oxygen by increasing the breathing rate in an attempt to take in more oxygen and by pumping more oxygenated blood through the body. Some of the other changes include a suppression of certain body systems such as the digestive system in order to conserve energy needed to increase production in the circulatory system. Some of the more visible changes that might appear include sleeping longer, dilated veins, fatigue, headaches, and in some cases repeat hyperventilation.

As mentioned earlier some of the facultative changes include the suppression of certain body systems as compensation for the increase in function of the circulatory system which allows for more oxygenated blood to circulate through the body. As the body becomes accustomed to the increased function of certain systems it will become accustomed to utilizing other systems such as the digestive systems at lower levels than individuals who live at lower levels.

From a developmental standpoint the body actually changes depending on gender. As mentioned earlier the reproductive systems of both males and females are impacted. The average age for a female to start menstruating is 13 in the U.S. In the Himalayas the average age is 17. Males can become sterile at young ages making reproductive rates relatively low in comparison to other areas. Women who do give birth run the risk of having children born with low birth rates increasing the chances of infant mortality.

Culturally the high altitude lifestyle garners as level of unity among its members and a relatively “calm” lifestyle in comparison to the fast paced style of the U.S. For example Nepal is a fairly large society that hosts a variety of people. Due to the increased level of UV exposure, almost all Nepalese people have a darker pigmented skin color and dark hair color. Both height and weight can vary but individuals who live at these altitudes generally practice a diet that includes heavily spiced foods and lots of grains to help with digestion. According to www.nepallink.com, about 80% of the populations are Hindu and they adhere to the traditional practices of Hinduism which adds to the feeling of togetherness among the people.

I think it’s important to study human variation across environmental lines because it helps us to understand our differences from an elemental level. It’s easy to look at someone and recognize the differences between us but it’s another to actually look at what causes the differences from an environmental and physiological stand point. For example when I began researching the people in Nepal I was aware that there would be significant differences between our lifestyles but I wasn’t aware of the challenges that they face and the differences that their bodies undergo in order to sustain itself in such high altitudes. It makes me have a better appreciation for people who face those types of challenges as I recognize the difficulty that I would have living in such an environment and it also makes me wonder about the amazing ability that our bodies have to adapt in order to survive. It gives the phrase “survival of the fittest” a whole new meaning. We can use this information to gain a better appreciation of people from different backgrounds.

When we look at individuals living in these altitudes it’s pretty easy to lump them into the same category of “race” because of the physical similarities that I’d listed earlier. But I think that what makes people living at high altitudes different is not specific to their “race” it has more to do with the body functions that have contributed to their level of activity and as a result; their way of life. In reality I don’t think “race” explains anything from a developmental standpoint. In a sense, everything starts with how we are made and the only way that we can really understand a person is by understanding how our environment has shaped our development. You can’t tell who a person is just by looking at them no matter how many people of the same color or race you’ve seen. Everyone develops differently at some point, there are different influences on each and every one of us all of our lives. Whether it’s the area where we grew up, the type of home we grew up in, our family and friends, socio-economic status, or the number of feet that we reside above sea-level, we have to consider all of the factors of our development as we work towards understanding each other. I think that as we expand our efforts towards understanding each other from a less superficial level we have a better chance at living together in relative peace.

http://www.bio.davidson.edu/Courses/anphys/1999/Yusi/adaptation.html

http://anthro.palomar.edu/adapt/adapt_3.htm

http://facstaff.unca.edu/cnicolay/BIO338/338-34-altitude.pdf

http://nepallink.com/nepal/culture-religion.html

The Piltdown Hoax

The Piltdown hoax was an event in which it is believed that three respected scientists conspired to get the public to believe that fossils of an ancient human skull were found in the small village of Piltdown in Sussex, England. This was an extraordinary find because prior to this supposed discovery, remains of ancient species had been found in many rival countries such as Germany and France but until that point only stone age tools had been found in Britain. Britain, believing that it was the greatest empire on earth, had never found remains of the “ancient man” and was eager to prove that it was the birthplace of the human race. This find could make this lofty goal a reality for Britain. This event started with a man named Charles Dawson who was an amateur geologist who had been given the remains of a skull by a laborer that was digging in a dirt pit. The remains were fragments of an oddly shaped jawbone that was difficult to identify due to the fact that it did not follow the structure of early humans or animals. Dawson took the remains to a well-known geologist Sir Arthur Smith Woodward with the Natural History Museum who helped him formulate his theory that the fossil was a portion of a human skull.  Later that summer Dawson, Woodward, and a French Paleontologists Father Pierre Teilhard, after more excavation they unearthed several additional items including: prehistoric animals, stone-age tools, and finally an ape-like jawbone with human-like teeth that seemed to link it to the skull that Dawson had from the laborer. On December 18, 1912 Dawson and Woodward presented the “Piltdown Man” to the world. It was nicknamed “the earliest Englishman”. This find had a significant effect on the scientific community and impacted not only archaeologists, geologists, naturalists, paleontologists, and even anatomists because this find was perceived to be the “missing link” in Darwin’s theory that gave physical proof of humans’ connection with apes and helped to explain our place in nature. It gained wide support through the endorsement of high profile individuals like Arthur Keith who was England’s leading anatomist. His and Woodward’s endorsement of the find dispelled any questions of validity. The popular acceptance of this find went on for some time without question.

In the 1920’s scientists began to discover ancient human fossils in Asia and Africa that were hundreds of thousands of years after the Piltdown find. Curiously enough these fossils were less human instead of more human. This anomaly led to a rise in the questions that had been in the minds of the scientific community members but who had been previously reluctant to voice their concerns out of fear of upsetting the more prominent and established members. But the seeds of doubt had been reinforced and resulted in a more thorough study of the Piltdown finds.

After WWII a new technology was developed whereby scientists would measure the fluorine content in fossils which allowed them to be dated. Chemical testing became a primary method of testing artifacts. In 1949 this type of fluorine test was conducted on the Piltdown fossils. Finally in 1953 a full scale investigation was conducted using these advanced dating methods. Chemical testing also revealed that the apparent staining on the fossils was not as old as previously thought and improved microscopic tools allowed scientists to determine that the teeth in the jawbone were actually filed down but allowing them to see the jagged scratches that were not visible to the naked eye. This combination of validation methods revealed that the Piltdown finds previously thought to have been the oldest found at the time were actually only about a hundred thousand years old. A massive hoax had been committed that would lead to questions for years to come.

Pride, self-interest, and greed were the major faults that led to this hoax. In general the desire for Britain to be able to compete with rival countries like Germany and France in this field was a major coup considering that it had previously been an area in which Britain had no standing. Additionally there is no doubt that this find gave standing, notoriety, and respect to the scientists involved at a level that was previously unknown. Arthur Keith used the find to bolster his own theories regarding the evolution of man and the fact that Woodward’s involvement removed any question of the validity of the find is proof that once a person had attained a certain level of respect their findings were unquestionable. Unfortunately this practice casts a dark cloud of the scientific process and makes me question all early finds in view of what was later proven. How many other prior discoveries were accepted on the basis of someone’s standing without true empirical proof of its validity? We may never know because the likelihood of anyone going back and validating all of that early data is unrealistic. This causes me to question current theories that were based on this early information. How much do we really know and how much did we assume based on who told us?

Unfortunately science like every other discipline is impacted by the “human factor” meaning that it cannot exist without human involvement. This fact alone ensures that science will never be “full proof” as some people tend to think. Unfortunately this hoax proves that as long as there is an opportunity for personal gain there will always be the possibility of data manipulation. 

Personally not only do I think it is not possible to remove the human factor I wouldn't want to. Our instinctive curiosity and wonder has led to some of the most amazing and magnificent discoveries. Also, our ability to think “outside the box” has enabled us to figure out solutions to abnormal and complex situations that computers and mechanics do not have the ability to discern. I think we went wrong in that we failed to do the very thing that the scientific method is known for namely validation and replication. The scientific community at this point in time accepted the findings based on the endorsement by certain individuals who were thought to be above reproach. I find this particularly funny because it’s no different that someone who believes in a religious theory told to them by their priest and doesn't question it because they believe that their priest is above reproach. 

The most important thing that I've learned from this hoax is that everyone has motives, some innocent, some malicious, and many based on pure greed. I know that I will not be a person who questions everything that I’m told because some things have to be taken on faith but I do know that when it comes to the important issues and questions about who we are and where we come from I have to do my own verifying and make a conscious decision about what I am going to accept on faith.  

Analogy/Homology Blog Post

a.     Briefly describe the two different species that possess the homologous trait. (5 pts)

For this assignment I chose the front limbs of human beings and fruit bats as the homologous structures that I will discuss. 

b.     Describe the homologus trait of each species, focusing on the differences in structure and function of the trait.  Why do these homologus traits exhibit differences between the two species?  Make sure your explanation is clear and complete. (10 pts)

The bones of a human's front limb are homologous to the bones of a bat's front limb. Both limbs contain the same type of bones, end in five digits, and have the same overall structure despite the differences in size. The two limbs have changed over time due to the uses performed by each species. Humans use their front limbs for eating, working, handling objects, etc. The front limbs of bats are actually covered by skin-like structure covered in hair that is used to as a part of the wing span that the bat uses to fly. In humans the finger-like bones do not extend very far because the uses for these structures has been used primarily for grasping and poking whereas the finger-like structures in the bat have elongated over time to form webbed wings which have adapted to their continued need to fly and remain airborne. The stretch of the bones allowed the length and width of the bat wing to extend in order to meet these needs which accounts for the difference in the way each limb looks today.

c.     

Who was (generally, not specifically) the common ancestor of these two species and how do you know that ancestor possessed this homologus trait?  (5 pts)

According to Wildclassroom.com there are some scientists who have theorized that fruit-eating bats may have evolved from the Primates making this the common ancestor between them and humans. It’s obvious based on their scientific classifications that they are linked. For example, both humans and bats share the following classifications:

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Although many species fall into these categories this is reason enough to suggest that they come from a common ancestor. Additionally the classification system developed by Linnaeus is based on common ancestors so the fact that both species share common classification groups is indicative of the fact that they share an ancestor. According to www.pbs.org, naturalist Karl Ernst von Baer observed that vertebrate animals, during the early stages of their embryological development, seem to have a common design, whereas the adult forms show difference. Arm buds from different species, are virtually indistinguishable when they first form on the embryo, yet they may develop into a wing, an arm, or a flipper.

d.     Provide an image of each species in this comparison.  (5 pts)

2. For your analogous traits provide the following information (25 pts):

a. Briefly describe the two different species that possess the analogous trait.  (5 pts)

Fish and Penguins.

b. Describe the analogous trait of each species, focusing on the similarities in structure and function of the trait.  Clearly explain why these analogous traits exhibit similarities between the two species.  (10 pts)

Penguins and fish are analogous based upon their similar “flipper” or fin-like structures. Both structures have different uses for each but they both originate from a need to navigate in the water. Fish use their fins to navigate through only water as fish are not land animals. Penguins on the other hand are both land and sea animals. According to www.livescience.com some scientists believe that penguins were originally only “land” animals but over a period of time evolved to spend prolonged periods of time under water in order to forage for fish and to survive by using water to escape from other animals that would hunt them for food such as polar bears.

Both penguins and fish use their fins “flippers” for navigation as well as for balance. Both types of fin exhibit similarities in structure. The humerus, radius, ulna, and phalanges are present in the structures for both animals. Despite being arranged differently it is clear, based on the similarities in structure, that the fins of these two animals show the ways in which each species has adapted over time.  

c. All pairs of organisms share some common ancestor if you go back far enough in time.  Did the common ancestor of these two species possess this analogous trait?  Why or why not?  (5 pts)

According to LiveScience.com there is evidence that the common ancestor of these two species is some type of sea turtle that evolved from another type of fish called an ichthyosaur to a leatherback sea turtle which are now extinct and over time into the penguin. Both of these species had fins that allowed them to navigate through the water so yes they did share this analogous trait.

e.     Provide an image of each species in this comparison.  (5 pts) A dolphin's flipper, bird's wing, cat's leg, and the human arm are considered homologous structures

http://phenomena.nationalgeographic.com/2013/02/07/meet-the-ancestor-of-every-human-bat-cat-whale-and-mouse/

http://www.nku.edu/~whitsonma/Bio120LSite/Bio120LReviews/Bio120LHomologyRev.html

http://askabiologist.asu.edu/human-bird-and-bat-bone-comparison

https://www.pbs.org/wgbh/evolution/library/04/2/pdf/l_042_03.pdf

http://www.thewildclassroom.com/bats/evolution.html

http://www.livescience.com/27434-penguin-facts.html

Protein Synthesis Blog

Here is my strand:

TCCGUAUGGUGAUUCUCGCCGGUCGGUUGGCGAGAUCAGCAGGUCGUAACUAGGUCCA

The Impact of Charles Lyell's Research on Charles Darwin

In my opinion Charles Lyell’s research and published works had the most significant influence over Charles Darwin and his theory of Natural Selection. In order to prove this let me start by providing a little history about Charles Darwin. Darwin was born in 1809, the son a reputable doctor and grandson of a physician, and scientist. As a result, there were high expectations for Darwin to follow in the illustrious footsteps of his father and grandfather who were respected physicians and intellectuals in their own right. Charles soon found that he couldn't stand the sight of blood and refused to participate in amputations, which were required in order to complete his studies. As a result moved out of the area of medicine and took an interest in the clergy. He quickly found that he was more interested in collecting scientific specimens more than reciting scriptures.  As a result of this determination he immersed himself in the study of organisms. He became fully acquainted with his grandfather’s research in the area of Zoology and that of the French Naturalist Jean-Baptiste Lamarck. Through his studies he met several people that would influence his growing interests in this type of study and dedicated himself to becoming a self-trained Naturalist.

 In 1831 Darwin was offered the opportunity to go on sea voyage that was to last for 2 years and cover the entire world. Darwin enthusiastically agreed and relished the idea of exploring new places and species. Darwin was first introduced to the work completed by Lyell on this voyage when he was given a copy of Lyell’s most famous work “Principles of Geology” that was given to him by the ship’s Captain Robert Fitzroy.

Charles Lyell was a geologist and a lawyer. His research focused on geological variations in the earth based on his evaluation of geological records and his observations regarding the structure of land masses and other materials. Lyell was a strict Unitarian who believed that “the present is the key to the past”. He argued that the formation of Earth's crust took place through countless small changes occurring over vast periods of time, all according to known natural laws. He believed that geological processes acting in the past were much the same as those we see today. This is the principle of Uniformitarianism. 

Lyell’s theory was very controversial because up to this time the popular belief was that the world was only about 4000 years old. This belief originated based on the biblical dating of the earth performed by Archbishop James Ussher and was the only accepted theory at this point in time. Ussher used a chronology based on the genealogy in the bible. He used a method that included the summation of ages of the 21 generations of people listed in the Old Testament. Ultimately he concluded that the creation of the earth occurred on October 4, 4004 B.C. this dating was accepted by the Church of England and was the only sanctioned theory regarding the date of creation.  Lyell’s theories about geological changes occurring of millions of years allowed Darwin the opportunity to expand his ideas about evolution of species by considering the possible changes that occur slowly over very long periods of time. Darwin delayed publishing his theory for over 20 years. There are several theories that discuss the possible reasons for this which include the belief that he needed the time to collect the necessary specimens and complete the remaining research needed to support his theory, his fear that his theory would be proven invalid by other contemporaries with more experience and expertise in the field, that he required the services of other correspondents and associates to validate his work, and finally his fear that his work would have a seriously adverse impact on society. It’s this last theory that holds the most weight in my opinion.  Unfortunately for Darwin the power and influence of the Church of England had grown exponentially and was considered profound and absolute during this period of time. Any dissenting ideas or opinions were met with strict punishment which could include banishment, imprisonment, and in even execution. With the church supporting Ussher’s theories Darwin’s views could be viewed as a deliberate attempt to derail the teaching of the church and make him subject to its wrath.  Howard Gruber, in his “Darwin on Man”, states that  “Darwin  sensed that some would  object to seeing rudiments of human mentality in animals;  while  others  would recoil  at  the  idea  of  remnants  of  animality  in  man.’’ Darwin’s delay in publishing his works may have been a deliberate attempt to lessen the social impact that he knew his work would have. Darwin was well aware of the firm foundation that Christianity had in the scientific community and he had no desire to be the front-runner for its demise.

Michael Ruse, in his recent book The Darwinian Revolution, sets some previous accounts within a sociological framework.  He argues:  The true answer [for his delay] has to be sought in Darwin’s professionalism.  . . . Darwin was not an amateur outsider like Chambers.  He was part of  the scientific network,  a product  of Cambridge and  a close friend of Lyell, and he knew well the  dread  and the hatred  most  of  the  network had  for evolutionism. . . . When telling  Hooker  of his  evolutionism,  Darwin confessed  that  it was  like  admitting  to  a murder.  It   was  a murder-the  purported murder  of  Christianity,  and  Darwin was not  keen  to  be  cast  in   this role.” 

While Ruse argues that it was Darwin’s professionalism that held him back from publishing his work, I contend that in addition to this his fear of the outcome of his work was the primary reason for the delay in his publishing it.

Ultimately I think Lyell’s research had the most profound impact on Darwin’s work. I do not believe that Darwin would've been able to develop his ideas regarding evolutionary changes without Lyell’s research because Darwin’s beliefs regarding natural selection are dependent on changes to the species occurring over millions of years. This would not have been possible if Lyell had not successfully dispelled the accepted age of the earth as determined by Ussher. In this respect I think that we owe a significant debt to Charles Lyell and Charles Darwin for taking the risk to develop such controversial theories that went against the prominent and accepted beliefs of the times to the ground-breaking work that paved the way for the development of evolutionary theory.

http://evolution.berkeley.edu/evolibrary/article/history_12

http://darwinday.org/learn-more/about-darwins-life/#college

http://home.uchicago.edu/~rjr6/articles/Why%20Darwin%20Delayed.pdf

http://www.pbs.org/wgbh/evolution/library/02/4/l_024_01.html

http://www.egs.edu/library/charles-darwin/biography/