Human Variation & Race

Cold temperature is an environmental stress that could disrupt the regulation of the internal processes of humans and lower a chance of survival. In very cold climates, there is a chance that the body could experience hypothermia, where the core temperature of the body drops to a dangerous level. 98.6 degrees fahrenheit is average for the core temperature of the body, and at 94 degrees, we will see hypothermia set in.

Humans have many responses to the cold which we use to keep warm. Some provide short-term relief, while others are more long term solutions. Our text book states shivering and metabolic increases as two of our short-term reliefs (p.422). Shivering and exercise increase the blood flow and the core temperature of our bodies. The cost is the use of energy that we must use to make these things happen. To provide the energy we must make sure we increase the amount of nutrients we intake. Carbs and fats are necessary to maintain a level of energy to keep warm in the short-term. Another short term response in humans is vasoconstriction, in which the blood flow is restricted through the veins, slowing the heart rate and keeping the heat inside the body. In the long term, humans have built fires and  layers of fat under the skin to keep warm. 

   

The largest benefit of studying humans in this manner is that we get to see how they have adapted to their own environment. We can see how different people from different backgrounds are able to individually adapt. For example, if we study the development of sickle cell in certain populations and how they build up immunities, we can use this information to help prevent or treat sickle cell in other populations. 

Race is not an effective way of studying human variation because we see immigration and migration world wide. Studying a general population based on environmental factors is a more effective way of determining what will happen to people who are born into or move into the same types of environments. We can compare results with other similar environments in other parts of the world. 

The Piltdown Man Hoax

It was 1912 in a small town named Piltdown, England when ammature archeaologist Charles Dawson claimed to discover a piece of an ancient human skull. Dawson soon called on the help of Arthur Smith Woodward and Father Pierre Teilhard de Chardin, and the three of them found several more bones that belonged to the same skull. The bones found were ape-like and human-like and they were the first of their kind to be found in England. It was a link that tied humans and apes, the findings were named Piltdown Man. This was big news for scientists and it was likely to answer a lot of questions for the ancestry of human and apes. The thought was that these bones belonged to the oldest of all human ancestors. Those in the community who did not believe in the findings of Dawson did not have much room at all to speak out against him, for Dawson and his work were prestigious and not to be challenged.  After the death of Dawson in 1916, the findings stopped and findings in other parts of the world were looking like Dawson’s findings may have been a hoax. In the end, it was only a distraction that led researchers and scientists down a dead end road.

Between the excitement of the find and the fear of questioning the legitimacy, the bones were not challenged, but they were idolized. Instead of thinking critically and using the scientific process, the people of this time and place accepted the idea that Dawson had just discovered this ancestor of humankind.

After WWII, scientists were able to measure the fluorine content of fossils and get a better idea of how old they were. In 1949, the Piltdown bones were tested and found to be much younger than originally estimated. In 1953, even more advanced methods of dating were used to find that the bones were less than 100 years old and that the staining was artificial. Testing also found the cuts of the bones to be made with metal tools.

As long as humans are “doing science”, there is no way to remove the human from the research. This means human emotion, error, opinion, and fault. Though it is the human factor in science that drives new ideas and new discoveries. All we can do to avoid future mistakes is learn from past mistakes and remain critical and open-minded of all scientific discoveries. The scientific method is an important process!

Life Lesson: This story probably has little to no effect on most people reading it, but we can take away something from it. It is important to question everything and form your own opinions. Do your own research and never follow blindly. When the research is above our heads, we must know who to go to for reliable advice and information. We have so many resources at our fingertips today!

Homology and Anology

I have always found humans and dolphins to be very similar. From the way they interact with each other to the way they express themselves (the extent of expression in dolphin is less noticeable of course). This extends to the way they become friendly, socialize, and care for their young.

The human and the dolphin, though very different species, hold a homogeneous trait. The human hand and the dolphin fin are similar in structure and function. It is not obvious from first sight, but once you hold the two bone structures side by side you can see the similarities. This homogeneous trait tells us that the two mammals come from the same ancestor some time ago.

It is said the land mammal and sea mammal split from a land mammal some 60 million years ago after the dinosaurs became excint. The mammal were able to split, grow, and become more diverse to live and survive in different parts of the land. 

The following is an interesting clip on dolphins: https://youtu.be/Cqzd0aKTWlY

   

When we look at the butterfly and bat we see two very different creatures. The butterfly is known to have bright colors, while the bat is grey or brown and hides out in dark places. Visually the two are opposites, but we do notice one very obvious similarity.

Both the butterfly and the bat have wings which are used for the same purpose, but nothing else about them are the same. Functionally the wings the same, but structurally they are very different. Bat wings have bones under skin, while the butterfly wings are made of membranes and tiny scales.

Unable to find a common ancestor between the two we can say that the two are evidence of convergent evolution, in which the each developed similar cultural adaptations as a result of environmental conditions. The wings of the butterfly and the wings of the bat developed independently.

DNA Decode

T T T A C A T T T C A G G G A A C G G A A C C C G G T A A A T C T T

Darwin and Malthus

1. Thomas Malthus had a tremendous influence over Charles Darwin. Though Malthus was not a scientist, he understood and studied the growth and decline of populations. Darwin studied the same field and found it to be important in explaining the theory of evolution and what he called "survival of the fittest".

2. Malthus was best known for his work and theories on population growth. A professor of history and political economy, Malthus wrote his most popular piece titled “An Essay on the Principle of Population” in 1798. He had recognized that it was possible for a population to outgrow its resources. If this was the case, the population was then exposed to starvation and disease among other struggles. The only way for the population to avoid such circumstances would be to control the growth of the population.

http://www.bbc.co.uk/history/historic_figures/malthus_thomas.shtml

3. The bullet point titled “Resources are limited” is an idea that strings together the theory of Malthus and the theory of Darwin. Malthus was known for recognizing that the resources of any population were limited, and it was up to the population to keep itself small enough to not outgrow the resources. Darwin was able to take this idea and build off of it into “survival of the fittest” in which those populations that are not controlled, only the strong survive. This is the theory of natural selection.

4. Darwin may not have developed his theory without reading the work of Malthus. Darwin has said himself that it was the influence of Malthus that got him thinking about many of the theories of evolution.

5. Darwin had the courage to bring to light the ideas that went against the beliefs of that time. The church was very powerful during this time and often times those who spoke out against the word of god were ostracized, threatened, imprisoned, or killed (Such as Lucilio Vanini in 1616 who was burned at the stake for questioning the existence of god)

http://www.executedtoday.com/2010/02/09/1619-lucilio-vanini-aka-giulio-cesare/

If I were stranded on a desert island...

If I were stranded on a desert island, I would bring a big sharp knife and a big healthy cow. The knife has many uses and the cow would be a good companion/source of milk. Hopefully I could keep both of us alive!