Tuesday, September 20, 2011

Week 5: Piltdown Hoax Blog Post


In 1912, Charles Dawson, an amateur archaeologist, was digging in a pit of gravel when he supposedly discovered remains of an ancient human skull. Dawson showed his find to Arthur Smith Woodward, who ran the geological department at the British Museum and also lived in the area. Woodward went with Dawson to the original site and together they found some more skull fragments as well as a jaw bone. In 1915, Dawson found a second set of remains that exactly matched the first ones recovered at Piltdown. The fossils were quite unusual. They had nearly human skulls with a large brain but the jaws had teeth arranged in a way that would have prevented speech. Piltdown man was often referred to as “the Missing Link” between man and apes. However, the validity of the fossils had been suspect all along. It wasn’t until 1953, some 40 years after it was first announced to the public that the fossils were officially declared to be frauds. The fossils were actually modern human skulls along with orangutan jaws with filed-down teeth. 

Human faults that come into play here in this scenario are their emotions. The British were very frustrated because they had not found any human fossil while the rest of Europe and Africa have found some. Even though there is no evidence who started this but the investigation combines their feelings and forging something like this to prove their evolutionary theories and to gain acceptance in the world of science. 

Fluorine absorption test are scientific process that were responsible for revealing the skull to be a fraud. The bones absorb fluoride depending on how long they have been buried. The greater amount of fluorine present, the older the bone. Piltdown jaw and skull contained trace amounts of fluoride; therefore, the fragments had been buried in recent times. The teeth had been filed down to disguise them and the canine tooth seemed to have been filed and colored with paint.

It is impossible to remove the human factor from science because human are big part of discovering histories. Humans are responsible for finding fossils and remains of ancient primates. With the proper procedure and thorough analysis, there would be less mistakes and a forgery could be prevented.

Life lesson I can take from this historical event is that any type of information always need to be analyze and verified. If they would have gone through a more scientific process to verify their findings from the beginning, the hoax wouldn’t have gone as long as it did. It’s always a good thing to do back up research of your own just to verify that information you are receiving from someone else is correct and acceptable.



               



Wednesday, September 14, 2011

Blog Post: Comparative Primate

Lemurs:     
 Lemurs are forest creatures. Many species live in Madagascar’s tropical rainforest, but some live in dry deciduous forests. The lemurs’’ strong hands and fingers help them to climb trees easily. Their muscular legs are adapted for jumping. When they need a change of scenery, they can hop to another branch. Brown lemurs and ring-tailed lemurs scamper along the forest floor on all fours but other lemur species find traveling on the ground to be a challenge. Lemur mainly eats grass, fruits, flowers, plant juices, leaves, seeds, seedpods, sometime insects and small lizards. It is very important to Madagascar because of the deforestation caused by humans; lemur can improve this situation by spreading the seeds from the fruits that they ate so the seed could grow into a tree which will help Madagascar’s environment. Lemurs are generally very small but they will vary in size depending on the species. They have noses that are long and pointed. They have opposable thumbs and they have nails but don’t have claws like many people believe. They have retina that are reflective and that makes them very shiny at night. Lemurs also have excellent vision which helps them with moving around at night. Lemurs do depend heavily on their sense of smell and this helps them to be able to recognize each other. They feature scent glands on the bottom of their paws and this allows them to leave a signature behind when they move. Lemurs don’t have a tail that enables them to hang from trees like so many people think. Instead, they rely on their tail for balance and to help them leave scent behind.  They are able to control their metabolism though and rely on very little food to survive. They have the ability to avoid breeding during times when food isn’t readily available. Their social groups vary in size from two to more than 20, and the females tend to dominate the males. The females also are responsible for defense of the group and usually bear a single off spring after a gestation period of about 18 weeks. The young lemur rides on its mother’s back for several months.

Spider Monkey:       
 Spider monkeys can be found in the forests of Mexico, Central America, and South America, but deforestation and hunting is damaging their habitat. They have prehensile tails that allow them to grip onto branches and the ground as they move. Spider monkeys have long, lanky arms and are very agile. They can be found in many popular zoos around the world. Spider monkeys have no thumbs but can still grip strongly onto branches with its other fingers and tail. They often gather together in groups of 20 to 30, but they sleep and forage for fruits, nuts, leaves, spiders, and bird eggs in smaller groups. They can be very noisy animals. Females typically give birth to one baby spider monkey at a time every two to five years. Baby spider monkeys usually stay under the care of their mothers for the first year of their lives. Their brains are less complex. Their thumbs are not opposable and their nostrils are further apart. These monkeys depend highly on their keen binocular vision and they have slender bodies and limbs with long narrow hands. Spider monkeys have a prehensile tail that is muscular and tactile and is used as an extra hand. The tail is sometimes longer than the body and both the underside and tip of the tail are used for climbing and grasping and so the spider monkey uses it like a fifth hand. When swinging by the tail, the hands are free to gather food. The spider monkey’s arms and legs are particularly long too. It has hooked-shaped hands because its thumbs are either absent or reduced to a stump. Hands are like hooks with long, narrow palms, long curved fingers, and no thumb. Thumbs are on the feet only. Male body length 38-48 cm, tail 63-82 cm, 9-10 kgs. Female body length 42-57 cm, tail 75-92 cm, 6-8 kgs. Males and females look the same. Their lifespan in the wild is about 27 years. Average 20 years in the wild, 33 years in captivity. Spider monkey is critically endangered, which means it is facing an extremely high risk of extinction in the wild in the immediate future. Considered good to eat and because of their large body size, spider monkeys have been severely hunted throughout their range. They are easy to locate because they are noisy and travel in big groups so they are often extinct in areas easily accessible to people. They are also affected by habitat destruction, particularly logging, which removes the tall trees that they depend upon. Spider monkeys are vulnerable because they have low maturation and reproduction rates.

Baboon:
 Baboons are the largest of the Old World monkeys. There are five distinct subspecies; each occupies a distinct portion of the total range of the species. Baboons travel across the dry savannahs and rocky terrain of the Arabian Peninsula, Africa south of the Sahara, and in the wooded savannahs of West Africa. Baboons live in well-organized troops, and the individual is only secure within his or her own troop. Large, dominant males rule the group and are responsible for keeping order among quarrelsome members and for protecting the group from predators. Baboons spend endless hours carefully grooming one another to remove insects and dead skin. They communicate in several ways, including posture, the way they hold their tails, screeches and yelps. Baboons walk on all four limbs, with their tails held in a characteristic arch. They eat plant matter, small animals and bird eggs. Some subspecies have rump patches of bright red or pink. Their faces have long, relatively hairless, dog-like muzzles. Male baboons weigh approximately 14 to 40 kg (30 to 90 lbs) depending on the subspecies. Females are about half the size of males. Their principal enemy is the leopard, but even leopards will avoid an encounter with the larger, adult male baboons, who are courageous and dangerous adversaries. Where leopards have been extirpated, humans and their dogs have replaced them as principal predators. Baboon mating behavior varies greatly depending on the social structure of the troop. The female initiates mating by presenting her swollen rump to the male. But “presenting” can also be used as a submissive gesture and is observed in males as well. Females typically give birth every other year, usually to a single infant, after a six month gestation. The young baboon weighs approximately one kilogram and has a black epidermis when born. The females tend to be the primary caretaker of the young, although several females will share the duties for all of their offspring. The young animals are weaned after one year. They reach sexual maturity in five to eight years. Baboon males leave their birth group, usually before they reach sexual maturity, whereas females are philopatric and stay in the same group their whole life.

Gibbon:
 
 Gibbons are found living in the tropical trees of Southeast Asia. Gibbons are rare, small, slender, long-armed, tree-dwelling apes. They spend most of their lives in trees. Because they are so dexterous while moving in the trees, almost no predators can catch them. Gibbons are social animals that are active during the day and they live in small, stable family groups consisting of a mated pair (a male and a female who mate for life) and their immature offspring (less than 7 years old). Female gibbons are pregnant for about 7 months and usually have a single baby at a time. Newborn gibbons are hairless except for a small cap of fur on the top of the head. Gibbons are physically independent at about three, mature at about six, and usually leave the family group at about eight, though they may spend up to ten years in their family groups. Gibbons are one of the few apes where the adult female is the dominant animal in the group. The hierarchy places her female offspring next followed by the male offspring and finally by the adult male. Gibbons typically weight about 15 lbs and stand about 13 feet tall. Most of their weight is in the upper part of the body, making them extremely good gymnasts. They can leap up to 30 feet in one jump. They eat fruit, leaves, and small animals.  Because of the rapid deforestation of their habitats, gibbons are an endangered species.
Chimpanzee:
Chimpanzees are our closest living relatives. They live in social communities of several dozen animals, and can habituate themselves to African rain forest, woodlands, and grasslands. Chimpanzees eat a wide variety of foods that include fruits, nuts, seeds, and insects. They occasionally hunt and eat meat. Chimps live in communities that are composed of family groups of three to six individuals, totaling about 50 animals. Hierarchies are formed by the adult males of the community, which is led by one alpha (the highest) male. Adolescent females may move freely between communities, although territory is strictly patrolled and conflicts can occur between neighbors. Standing approximately 4 feet high, males weigh between 90 and 120 pounds, while females weigh between 60 and 110 pounds. Chimpanzees rarely live past the age of 50 in the wild, but have been known to reach the age of 60 in captivity. Most mothers give birth to one young an average of every five to six years in the wild. Young chimps stay with their mothers for up to 10 years. Habitat destruction is the greatest threat of the chimpanzee. Large population decreases are also blamed on hunting and commercial exportation.
Summarize:
The level of influence the environment has on the expression of physical and behavioral traits is very high. If they don’t adapt to the environment, there will be less chance for them to survive. Post primates lived on the tress to avoid predators. They eat fruits, nuts, seeds, and insects to survive. Because of Deforestation, most primates are endangered of becoming extinct due to population decreases