Human Race & Variation Blog

The stressor I chose was high levels of solar radiation. I think the growing prevalence of cancer, specifically skin cancer is probably why I chose this particular topic. It's our skin's ability or inability to catch up to the growing amount of solar radiation that we're being exposed to that negatively impacts the survival of humans. Primarily because those of us with ancestry that didn't require much protection initially, such as myself who is German and Danish (AKA northern European), has a very low to zero capability to create melanin in my skin as a response to the living closer to the equator as my ancestors. It's been reported that European Americans are 10x more likely to develop skin cancer than African Americans. 

There are four ways humans adapt to this stressor. They are:

1) Short Term: I would say that our body's ability to create sweat in order to deal with the over-exposure to heat is one. It's our first reaction when exposed to higher temperatures than what our body is capable of dealing with.

2) Facultative: This happens through the skin creating more melanin in the epidermis when being exposed to sunlight. This is also known as "tanning".  It's the body's way of creating a quick defense for the skin when being exposed to harmful UV rays. Even those with naturally dark skin will create more melanin to a certain level. 

3) Developmental: This is very similar to "tanning" or the facultative adaptation, however this one spans through generations because it's a trait one is born with as opposed to one that happens as an immediate reaction and then dissipates. Unlike tanning that will go away or return the skin to a homeostatic state in a matter of days, the skin color change that occurs through many generations of humans living in a particular geographic region has long lasting effects. Those humans that live closer to the equator have significantly darker skin with more melanin that those who live closer to the north and south poles. The many variations of skin color throughout the human race are developmental adaptions to the amount of heat and sun exposure those areas have provided throughout the process of evolution.

4) Cultural: We have all adapted to the heat and amount of sun exposure through cultural practices. It ranges from our housing units, umbrellas (or anything that produces shade), using SPF when outdoors, wearing hats to protect our faces and even our clothing. (The picture I posted of the umbrellas is from Taiwan, and it was not a rainy day. Taiwanese women protect their skin from the harsh rays during the summer through the extensive use of umbrellas.)

It's easy to describe the adaptations described above in terms of race because it can be generalized that all Africans are dark-skinned, Asians are medium toned, and Europeans are all light skinned, but that's a very incorrect and gross generalization. Especially today when so many countries are multi-cultural. 

I believe that understanding why we all have such various physical traits helps debunk the concept of "race" which is really nothing more than a sociological creation. There is a difference in the physical traits of one whose ancestors were native to India than one whose ancestors are from Korea yet they are both "Asians". Being able to break-down and understand how and why these physical adaptations manifested in the first place helps us better understand humanity as a whole. As we (humans) keep migrating throughout the world, these traits will continue to evolve and change through the years. I think that through our differences we obtain unity. 

Piltdown Man Hoax

The Piltdown Hoax was one of the largest frauds in the scientific community and began with the discovery of a supposed  human-like skull (which included a piece of a jaw with two teeth) and primitive stone tools in a gravel pit in Sussex, England on December 18, 1912. The discovery was made by amateur archaeologist Charles Dawson who then pulled in Arthur Smith Woodward of the British Museum of Natural History. Together they brought England into the spotlight because at that time there had never been any successful human remains found on the British Isles. Needless to say this discovery was a significant find for England and thrust it into the scientific spotlight immediately. The discovery was thought to have finally concluded Darwin's still-controversial theory of evolution.

It took the scientific community almost 40 years to discover that the remains were fake. There was much speculation along the way within the scientific community because other discoveries elsewhere in the world simply didn't connect to the Piltdown Man. Things such as a other skulls being discovered in Africa not having the ape-like jaw or large brain such as the Piltdown Man. Unfortunately nobody spoke up about their doubts because Arthur Smith Woodward was a very prestigious man and colleagues simply didn't feel comfortable challenging his finds. It wasn't until new technology came out around 1939, such as fluorine testing, that the scientific community truly had the basis to do conclusive tests. Finally the remains were formally tested and in 1953 authorities of the British Natural History Museum announced publicly that the remains were - in fact - a complete fraud. As a matter of fact, carbon testing late showed that the skull was less than 600 years old.

I think there are many human faults at play in this scenario. First of all, greed and a need for fame on the part of Dawson and Woodward are significant. Although it is believed that Dawson was actually the mastermind because of later discoveries of more fake fossils in his repertoire, I believe Woodward is just as much to blame because he jumped on the bandwagon immediately out of overexcitement and possibly a need to be attached to what was supposed to be the most significant human evolutionary discovery. 

Secondly, the fact that quite a few scientist had doubts and never spoke up out of fear or respect for Woodward prolonged the discovery of the fraud longer that it should have been. Although the fluorine testing didn't come around until dozens of years later, had someone said something sooner, more research could have been done and the fraud could have possibly been exposed sooner. The entire scientific community was thrown off for nearly 40 years.  That's a long time and a lot of money spent barking up the wrong tree. 

The positive aspects of the scientific process itself are the technologies and tests that can be done to keep from something like this happening again. The fluorine testing and even better, carbon-dating, were invaluable to exposing this fraud. 

I don't think it's possible to take the human element out of science, and I'm pretty sure I wouldn't want to. It is the human curiosity and the need to discover truth that leads scientists down there paths. It's the drive of passion. Without that, there would be no truly amazing and mind-boggling discoveries. I just believe we are now fortunate to be able to test such findings and discoveries through modern technology. Sometimes the most amazing things are found through mistakes.

As far as life lessons, it should teach everyone that not everything can be believed regardless of the source it's coming from. Especially in this day and age when so many people seem to believe everything they see and hear on the internet or television. The internet in particular has to be one of the largest pools of misinformation in our world today. I certainly will never share info again unless I triple check the source it 's coming from. 

Homologous vs. Analogous - Week 3

Homologous

I chose to compare Whales and Snakes for Homologous traits because they both came from early tetrapods (4-legged creatures). They are also completely polar opposites in size which I thought made a fun comparison. Admittedly these might too far apart to count because they don't currently possess the same trait, but they did at one point. 

While whales obviously do not have four limbs, research has shown that they actually DID at one time and eventually lost their two smaller hind legs adapting to life exclusively in water. Whales still technically have traces of a pelvis and at times (although rarely) are born with vestiges of hind legs. 

Snakes, on the other hand, have no legs but research suggests that some, if not all, actually did at one point. It is believed that they eventually stopped growing them because it potentially destroyed some form of movement such as burrowing into the earth.

Analogous

I chose Birds and Butterflies for this because by most esthetic and functioning purposes, they would seem to homologous because of their wings. While the wings have the same function, for mobility and flight, that's pretty much where the similarity ends. Bird wings are made of bones and are adaptations of what was formerly their front legs. Butterfly wings are completely separate appendages. Birds are believed to have evolved from theropods and insects evolved from arthropods - neither of which had wings.

I've tried to find the common ancestor of of these two groups and it's like going down a rabbit hole! I just can't seem to figure it out. :(

Protein Synthesis

Hi all! Here's my strand code:

GTTATACCAACCGAACGTCTGAACGCAAGGCTTGATCCACG

Peace out!

Historical Influences on Darwin

1. Select one of the five individuals listed above who you would argue had the most influence over Darwin’s development of his theory of Natural selection. This could be a positive or a negative influence.

Thomas Mathus and his book Essay on the Principle of Population


2. Briefly (but completely) describe the contribution this individual made to the scientific community. 

Thomas Malthus was interested in everything related to populations. He highlighted the interrelation of food supply and population in that food production increases arithmetically while population growth occurs naturally and at a faster rate. It is because of these things that poverty and famine were inevitable unless the population growth was controlled (such as birth control). He contended that there simply was not enough energy to maintain new births and creation.

He also contended that overpopulation was being battled naturally and historically through war and disease.

Source links: http://www.allaboutscience.org/malthus-faq.htm and  http://www.uwmc.uwc.edu/geography/demotrans/malbox.htm


3. Identify the point (or points) most directly affected by this individual’s work and thoroughly explain how this point was influenced by your selected individual.

There are a couple of points actually.

• Nature has the potential of reproducing at rapid rates
• Population growth only occurs as much as current resources allow and
• There are limited resources on the planet


4. Could Darwin have developed his theory of natural selection without the influence and ideas of this individual?  

Not in my opinion. He took an already existing theory and merely elaborated on it more than Malthus was either capable of or wanted to (given Malthus still attributed everything "divine institution".) Without ever having learned about the potential struggle for existence and the rapid pace of population in conjunction to available resources, he would not have had the foundation for Natural Selection.


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

At that time, the Church held massive power and Darwin was actually training to be an Anglican priest. At one point he described his fascination with nature as having been associated with his strong faith in God.

The attitudes of the Church or those that disputed the teachings of the church made him doubt his own science and delayed the publication of Origin in order to stay in good social standing.