Tuesday, September 23, 2014

Piltdown Hoax

The Piltdown hoax occurred in 1912 in Piltdown, England, when amateur archaeologist Charles Dawson was digging in a gravel pit. He then supposedly discovered a piece of ancient human skull. The top of the skull looked like a modern human’s, but the jaw was very similar to an apes. He then invited Arthur Woodward to Piltdown, and since Woodward was a well-established and respected archaeologist, the finding was deemed revolutionary to the theory of human evolution. The people of England were enthusiastic and thrilled that their country too had ancient human fossils. It supported the idea that many scientists believed that human evolution began with the brain, and upright walking came later. We now know this is incorrect, as upright walking came first, then the larger brain. For forty years the hoax went undiscovered and scientists went on following this model of human evolution. However, new skulls were then being found in Asia and Africa which appeared to look more like apes, and less like humans. These fossils were much older than the Piltdown findings, and this conflicted greatly with the timeline of human evolution. Then, scientists began testing the fluorine content of fossils to calculate their age. It was learned that the fossils Dawson found were not more than 100,000 years old. Additionally, closer analysis showed intentional staining of the fossils and filing down of the teeth to make them look more human. The hoax setback our understanding of human evolution, but it also taught scientists to test evidence more thoroughly.
            Many human faults came into play with the Piltdown hoax. The biggest issue was the egos involved in the fake discovery. Regardless of who committed the falsification, one of the men involved let their pride takeover and wanted to achieve success without having to work for it. He wanted to receive notoriety for his discovery so he could feel important in his field. Furthermore, nationality and patriotism comes into play, since many people of England believed this information at face value simply because they wanted their country to have ancient human fossils like Asia, Africa, and other European countries. Furthermore, at the time, these Piltdown fossils were thought to be the oldest yet, once again inflating the pride of English scientists.
            By measuring the fluorine content of the fossils, scientists were able to determine the approximate age of the ancient skulls. They could also see that a steel knife was used to cut the remains, along with artificial staining. When they examined the remains under a microscope, they could see scratch marks on the teeth, indicating the teeth had been filed down.
            I do not think it is possible to remove the human factor from science. We can take as many steps as possible to reduce its presence in science, but it can never be wholly eliminated. We are human beings with flaws and emotions, and we can never be completely objective. However, I do not always think this is a bad thing because it can lead to improvements in evidence testing (as it did with the Piltdown hoax), and it leads to new innovations and opinions every day in science.

            In all aspects of life, but especially when it comes to scientific information, I think it is extremely important to research and test evidence in order to verify its validity. If we simply accept what is told to us without questioning it, then we will miss out on the truth of many situations. We need to question and doubt in order to learn new ideas. 

Wednesday, September 17, 2014

Comparative Primate Traits

Lemurs are found only on the island of Madagascar and in some close by islands on the east coast of Africa. Madagascar is an extreme ecological niche for these lemurs to live in, as they have a rain forest in the east and the west is very dry. They also experience severe droughts followed by flooding, which causes very little plant growth. Most lemurs are very social and live in groups of 10-15, comprised of males and females of all ages. Only nocturnal lemurs are solitary. Lemurs are seasonal breeders and usually only breed for three weeks every year. They must time their breeding to deal with the food availability and harsh weather of Madagascar. They use vocal pitches to communicate with one another. Since lemurs are the only nonhuman primate living on Madagascar, they have no competition from other primates to threaten them. Therefore, they have been free to develop many different social groups, some solitary, some paired, and some larger groups. However, the island’s extremities have caused them to alter when they will mate, which only gives them a small window of time to reproduce.

Spider monkeys live in the tropical rain forests of Central and South America. They are arboreal, meaning they live in trees, and they deal with high temperatures and high amounts of rainfall. Spider monkeys are very social and live in groups of two to three dozen. During the day, they split into smaller groups to forage, and they do the same at night when they sleep. They can communicate with another through gestures and different calls and screeches. When a female is ready to reproduce she chooses her male and they sniff one another to make sure they are ready for copulation. A female spider monkey usually has one baby every three to four years. Since spider monkeys live in tropical rainforests, they are threatened by many predators, including snakes, leopards, and tigers. As a result, spider monkeys adapted to their environment by forming such large social groups. In this way, they provide support from one another and are able to communicate with each other in order to avoid danger.

Baboons live throughout sub-Saharan Africa and live in many types of regions, including savannas, mountains, tropical forests, and deserts. Baboons are terrestrial and spend most of their time on the ground. Their group sizes can range from 10-200, which is primarily due to which type of environment they live in. Baboons that live in savannas have much larger groups, as opposed to desert baboons. Females start reproduction by putting her swollen butt toward a male baboon. After six months, the baboon gives birth to one baboon. Baboons adapted to their environment by grouping together as much as they can to find food and water supplies, especially those that live in the desert.

Gibbons live in Southeast Asia, islands, and China and live in tropical rainforests. Gibbons are arboreal and are the fastest at swinging from tree branches. Their social groups usually include a male, a female, and their offspring. Most gibbons are monogamous and extremely territorial. They protect their territory by singing every morning as a warning to predators and other gibbons. They have adapted to their environment by doing so, since there are many predators that face the gibbons.     


Chimpanzees live in central Africa in tropical rainforests. However, with deforestation, many chimpanzees are now forced to find new areas to live. Chimps live in large communities ranging from 10-100, and often the males of the group form a close bond. Together, they protect and defend their territory. This is especially important because of deforestation. Chimps are now even more vulnerable to attack, since they spend most of their time in trees sleeping and eating. Chimpanzees do not have seasons of mating; they mate throughout the year when the female is receptive. Chimps have adapted to their environment by forming large groups that protect one another and forage together. 

Ultimately, I have found the environment that a primate lives in has a huge affect on their behaviors. I also noticed that it had a very similar effect on primates, with most primates forming large groups in order to protect one another from predators and other threats. Additionally, I discovered that mating for some primates was dependent on food supplies and overall conditions. 

Thursday, September 11, 2014

Homology and Analogy

Analogous Traits
a) Sharks are cartilaginous fish and typically live in very deep waters of the ocean. They have gills and breathe by extracting oxygen from the water. They are carnivorous hunters and spend most of their time searching for food. Dolphins are marine mammals and generally live in shallow waters. They have lungs and nurse their young, and they are also carnivores.
b) Sharks and dolphins both possess the analogous trait of dorsal fins and pectoral fins. They need these fins in order to maintain stability while swimming with agility. Dorsal fins sit on top of both of the animals and help keep them upright. Pectoral fins are located on the sides and help them turn and stop. Both the animals had to develop these fins because they needed them in order to swiftly swim, not because their ancestors shared this common trait.
c) No, the common ancestor of sharks and dolphins could not have shared this trait. We know this because sharks are fish, whereas dolphins are descended from mammals. As a result, their common ancestor could not have had this trait.





Homologous Traits
a) Crocodiles are aquatic reptiles that are carnivorous and are adept swimmers. They have a streamlined body and four limbs. Mice are small rodents with tiny ears and long tails. They have four limbs and an extremely good sense of hearing.
b) The homologous trait these two share in common is four limbs. The same bones support both animals, but they are differently shaped. Crocodiles implement a "high walk" where they lift their entire body trunk and at least the anterior half of their tail clear of the ground. Crocodiles also use their limbs to help them swim. Mice use all four limbs to walk and run. They stand on their hind legs a lot more than crocodiles do, mainly to eat. Ultimately, even though they share the same limbs, they use them for differently and they are shaped differently.
c) The ancestor of crocodile and mice are tetrapods, which are animals that are vertebrates. We know that tetrapods developed limbs because we can see these in fossil records.