Heat

Heat as an environmental stress on a person negatively impacts the survival of humans by disturbing homeostasis. It does so by making it harder for the body to lose excess body heat. With the addition of high humidity, it becomes even harder for the body to cool itself because the sweat does not evaporate as quickly. Heat can cause heat strokes which can result in death when severe enough.

A short term way humans have adapted to heat is by sweating.  Sweating is the body’s way of releasing excess heat to prevent the body from overheating.

A facultative way that humans have adapted to heat is by tanning. By tanning, a person's skin tone becomes temporarily darker making it so that the surface of the body absorbs more of the heat from the sun. 

A developmental way that humans have adapted to heat is by hair loss. Humans have adapted to being less hairy in order to better regulate heat. We lack a lot of body hair that most other animals have. 

A cultural way that humans have adapted to heat is by their choice of clothing. When it’s hotter, people often choose to wear clothing such as shorts and tank tops. They also choose to wear clothes that are lighter in color and lighter in terms of material. People may also wear hats to shade themselves from the heat from the sun.

Piltdown Hoax

The Piltdown hoax was a situation in which someone forged fossils that seemed like they were a lot older than they actually were and of a different species than the original bones.  The fossils were found at a site in Piltdown in the England in 1912 by geologist Charles Dawson. At that time the fossils were significant because they suggested that humans developed a large brain before they walked upright. This discovery caused different effects on the scientific community because the fossils were thought to be the oldest human fossil remains. These fossils could be used as evidence of Darwin’s theory.

            The biggest human fault that came into play was self-interest. The scientists involved in the finding of these fossils were very focused on how the findings benefited them. Because their focus was on self rather than science, objectivity no longer was a factor in the evaluation of the fossils. Like the video states, any evidence that may have disputed one of the scientist’s theory could have been thrown out. They accepted evidence that supported their theories. Their lack of objectivity greatly impacts the scientific process because they choose what lines up with their ideas rather than what is true and proven.

            A positive aspect of the scientific method that was responsible for revealing the skull to be a fraud was further investigation using more advanced tools. Scientists that were not involved in the finding of the fossils and therefore more objective, ran chemical tests that proved that the fossils were not as old as first imagined. They also looked at the teeth under a microscope which proved that the teeth were filed down to the size that they were indicating that the fossils may have been forged.

            I don’t think that it is possible to remove the “human factor” from science to reduce the chance of errors like this happening again. Everyone has their own agendas and often hears what they want to hear so to speak. I wouldn’t want to remove the human factor from science because it is that human factor that leads the way to new discoveries and innovations based on different scientists’ passions and biases. I think it is just important to make sure that things are cross-checked and the scientific method is used properly.

            The most important life lesson to take away from this historical event is to always get the facts straight. It is important when doing any type of research to cross check things and make sure that sources are reputable. It is important to not believe everything that is told to you without proper verification. It is also important to be skeptical about things in order to make sure that what you’re accepting as fact truly is factual and not based on opinion or biased research. 

Homologous and Analogous Traits

Homologous Traits:

            If two species have homologous traits or structures, they are considered to share a common ancestor. Two species that have homologous structures are the frog and rabbit. Frogs are amphibians that live both on land and in fresh water. There exists thousands of different species of frogs, but all have similar anatomies which include lack of tail, long hind legs with webbed toes, large eyes, and smooth or warty skin. Rabbits are mammals that mainly live in North America along with some places in Europe, Southeast Asia, Africa and South America. Rabbits have long ears and large hind legs. Their paws lack pads, but have strong nails that are useful for digging.

            The forelimbs of the frog and rabbit are homologous structures. Frogs mainly use their forelimbs to balance themselves and for movement. Anatomically, it has about 15 different bones. It looks like an “L” with 4 fingers at the end. Like frogs, rabbits also use their forelimbs for balance and movement. Unlike frogs, they also use their forelimbs to grasp things. The forelimbs of both rabbits and frogs are shorter than their hind legs. Although their forelimbs are structurally similar, there are a few differences. Frogs have less space between the ulna and radius bones. The angle between the Humerus and Ulna and Radius is more obtuse than that of the rabbit’s. There exists these differences between the species because of the anatomy of the rest of their bodies. The wider angle allows the frog to balance at a wider stance.

            The common ancestor of frogs and rabbits is the Eusthenopteron which is a genus of lobe-finned fish that lived over 385 million years ago, but are now extinct. It is debated whether or not these fish lived strictly in the water or also spent time on land. Fossils from transitional species like these suggest similar structures in their fins to a humerus, ulna and radius. It is these similar structures that suggest that it is the common ancestor to both frogs and rabbits.

           

Analogous Traits:

            An analogous trait is the result of two species having similar environmental pressure that caused them to develop similar structures, rather than having a common ancestor that produced the similar structures. Two species that share an analogous trait are dolphins and sharks. Dolphins are aquatic mammals. Although they are found in oceans worldwide, they are descendants of land mammals. Sharks are fish that have over 465 different known species. The earliest known shark dates back over 420 million years ago. 

            The fins and flippers of dolphins and sharks are analogous structures. Even though these structures are anatomically different, they serve similar functions to each animal. Both the shark and dolphin's dorsal fin serves to balance the animal and keep it upright. The tail fin helps to propel them forward. The pectoral fins both help to balance them and help them turn.
            Although these structures are not a result of having a common ancestor that possessed these traits and passed them down, the common ancestor of the dolphin and shark which is an aquatic vertebrate most likely possessed a similar body shape, fin and flippers. Even though the common ancestor possessed these structures, the traits are still analogous because they were acquired due to environmental stressors rather than heredity. Because the dolphin evolved from a land mammal, it didn't acquire its fin and flippers until it entered the water.

Protein Synthesis

GCTCTACCACGAGCTTAGTGGGAACGTCCCGTTAATCACGT

Jean Baptiste Lamarck was one of the first scientists who proposed an idea of evolution. He was considered a naturalist and argued for the inheritance of acquired characters. He is known for his work on classifying invertebrates, a term he coined himself. Source: http://evolution.berkeley.edu/evolibrary/article/history_09

Two of the bullet points that most directly relate to Lamarck's work are:

• If the environment changes, the traits that are helpful or adaptive to that environment will be different.
• In order for traits to evolve and change, they must be heritable.

Lamarck recognized that the environment plays a huge role in evolution. He acknowledges that species adapt to their environment. Darwin came to similar conclusions about the environment's role in evolution. His theory about the inheritance of acquired traits influenced Darwin's theory of evolution because in introduced the idea of heredity in evolution.  

One bullet point that doesn't agree with Lamarck is:

• Individuals do not evolve. Populations do.

Lamarck hypothesized that individuals change and adapt to their environment which in turn leads them to pass on those traits to their offspring. According to Lamarck's ideas, evolution could therefore occur within generations which goes against Darwin's reasoning that evolution happens between generations.

I don't think that Darwin could have developed his theory of natural selection without the influence and ideas of Lamarck. Lamarck was a naturalist before Darwin and was one of the first to propose the idea of evolution through the inheritance of acquired traits. Darwin's theory is influenced by Lamarck's proposal that species inherit traits from their parents, although Darwin rejected the inheritance of traits as proposed by Lamarck.

Because the church supported the Biblical account of creation, Darwin faced challenges in publishing On the Origin of Species which proposed an alternative theory to creation than that proposed in the Bible. The church was definitely not supportive of Darwin's theory of evolution and rejected it, making Darwin reluctant to publish his book.

Stranded on an Island

If I were stranded on a desert island I would bring a very large, warm, water-resistant blanket as well as a solar powered flashlight. I need the blanket because I feel very comforted by large fuzzy blankets. It would keep me warm and dry for the cold nights. The flashlight is an absolute necessity because I get very anxious in the wild at night when I can't see my surroundings. The flashlight would also make it so that I could make myself visible to any plane that might fly overhead during the night.