Tuesday, September 23, 2014

Piltdown Man

1.      The Piltdown hoax occurred in1912 in the village of Piltdown where Charles Dawson claimed to have found a piece of an ancient human skull while digging in a gravel pit. He then invited England’s leading geologist Arthur Smith Woodward and French paleontologist Fr. Pierre Teilhard de Chardin and they spent a summer discovering fossils that put together the skull of the later named Piltdown man, but the biggest finding was the jawbone that looked like the jaw of an ape but had the teeth of a human. This was significant because it showed a common ancestor shared by humans and apes that was possibly, what they both had evolved from, an addition to the evolution tree. It also showed that theory of England’s leading anatomist Arthur Keith that humans developed big brains before they walked upright was correct, which is the contrary of what scientist have discovered up to this day that upright walking was developed before big brains. In the1920s new remains were discovered around the world that did not match up with that of Piltdown, the new finds were from thousands of years after Piltdown man but the skulls were less human like. In 1949 scientist performed a fluorine test on the skull and discovered that it was only a few hundred thousand years old instead of millions. Then in 1953, there was a full-scale analysis and it was uncovered that the skull was fake. In the jaw, they found that the teeth had been filed down and the jawbone was only a few hundred years old, the jawbone was from a female orangutan.  It become obvious that the fossil had been manmade, scientists were stunned on why someone would do this. It has since been found that Dawson forged this and other founding’s.
2.      There are a few human faults that came into play in this hoax. One fault is that of all the English scientist wanted to have a fossil found in their home England that they didn’t seem to care to investigate the person who had found this fossil and took complete faith in this amateur jus to get what they wanted. Another fault was that of scientist like Keith who benefited from the finding that supported just because it proved his theory.  Also another fault that many were guilty of was the fear to challenge the hierarchy of scientist, nobody came forward to challenge the finding.
3.      After World War 2 scientist found that by measuring the fluorine content in fossils they could roughly tell how old they are. In 1949 as previously stated they performed this fluorine test and found that the skull was not as old as had previously thought. In 1953 they found that the staining on the bones had been superficial and artifacts had been stained, material that had been cut was cut when it was already fossil using a steel knife. When under the microscope the found scratch marks that showed that the teeth had been filed down. Pieces had been removed from the jawbone so that it would not show that the bones did not match.
4.      I don’t think it would be possible to remove the human factor of science, I think that this factor is not completely bad although it did allow for this hoax to happen it was also the reason the hoax was uncovered. The human factor contributes a lot to scientific discoveries good and bad but I would not remove this factor from science because I think that is needed to keep scientist improving in order to prove which theories really are correct and find further information or create new methods to disprove other theories or hoax.

5.      The lesson to be learned is to always double check your resources and make sure they are reliable before crediting their work or you might end up being falsely informed like Woodward.

Wednesday, September 17, 2014

Sociality and Mating patterns

LEMURS
Lemurs can only be found on the island of Madagascar and the nearby Comoro Islands, but it is thought that the first lemurs on the Comoro Islands were brought by humans so the focus will be on those of Madagascar. Madagascar is 250 miles away from Africa creating an isolated environment for lemurs.
Lemurs are basically only active at night and make eerie noises. Lemurs are very sociable with one another and form groups that average around 15 individuals.Most lemurs spend their time in trees although some do spend time on the ground. Lemurs also participate in social grooming almost as if to feel closer as a group. In the lemurs society the females generally dominate the males in interactions. Mating season usually last less than 3 weeks per year, as the females only stay estrus for a couple days. Although if food supplies are low they will avoid breeding. When its time to mate the males leave the group and look for other females, as for the females they stick together. 
Although the Lemurs are now on isolated islands their traits show that they once lived around many predators. Roaming at night would be a way to get around while bigger predators are sleeping. Staying in groups also gives them a slight advantage of power in numbers or at least a small intimidation factor towards smaller predators. Clearly spending their time in the tress is a way to avoid predators as well. Since the Lemurs body size makes them easy targets for predators so they don't have much time to spend mating thus the shortened mating period. As for the lemur who do walk on the ground now is because they are adapting to their environment and no longer have the large number of predators hunting them on their isolated environment.




SPIDER MONKEY
Spider monkeys live in tropical forest environment found in central and south America as well as mexico. Spider monkeys inhabit trees thriving in upper the upper canopy without the competition of other primates. The vast forrest supplies a plentiful amount of food for these omnivores. Spider monkeys are very social and live in medium sized groups. There are a few individual monkeys who dwell by themselves but in close range to their group. They have been known to live in large groups but only when seeds; a major component in their diet; are in abundance. In their society females have a more leading role than that of their male counter parts. as females are often the ones that are better at finding more varied food routes. Spider monkeys are awake during the day and sleep at night. It is difficult to tell the difference between males and females although males are slightly larger. Females also sexually mature before males at the age of four, males are sexually mature at the age of five. Spider monkeys breed all year long as their is no regular breeding season. With offspring born one at a time and babies are born black and are carried by the mother hanging by the ventrum until five months of age which they are than carried on the mothers back and nursed until the age of two.
Spider monkeys have no need to compete for food which contributes to their social ways. Due to their smaller size and social behavior being in medium sized groups helps them find safety in numbers. The forest has large tall trees and that gives spider monkeys the advantage of sleeping far from predators and also the ability to defend themselves by throwing objects from branches since most predators cant reach them although they preferably rather run than fight. Since there is wide variety of food for them to eat in the rain forest this allows them to breed all year long.
BABOON
All five species of baboons can be found in either Africa or Arabia. Most baboons can be found in savannas and other semiarid habitats but a few also live in tropical forest. Which are also home to cheetah lions and hyenas to name a few predators.
Baboons stay in groups of 30 to over 200 members depending on the availability of food. The female baboons remain with the same group into which they're born their entire life, while males leave and join new groups when they mature. Females thus form strong and maintain strong social bonds with their female kin. Males on the other hand do not form strong social bond with other males they leave their group also known as troops around puberty and join a new troop to reproduce. The females show their strong social bonds through grooming one another and through these strong bonds there is greater infant survival and greater longevity. While males interactions are more likely to be agnostic because males have a dominance relationship. Males compete over the highest positions in the troops dominance hierarchy, where the alpha male gets first access to ovulating females. 
With the wide variety of predators found in the baboons environment it is best for survival if they stay in larger numbers, as staying in these number also increases the survival of the offspring. Having such large groups it is necessary to have a strong social bond between the females in order to keep peace within the troops. Also it is considerable that due to the number of predators it is beneficial to have the strongest or alpha male leading.
GIBBONS
Gibbons can be found in the dense forest of southeast Asia. The vast amount of trees make a formidable habitat for these branch swingers.
There are also predators like tigers living on the ground of these forests.  
Gibbons are monogamous and live in family groups consisting of adult pairs and their offspring. They stake out territory and defend it as a family. Gibbons unlike the other small primates do not find strength in numbers but instead feel it easier to move around with just their family. Since the forest provides vast trees the gibbons do not spend time on the ground since they have the availability to swing around.Since they spend time in just family packs they are territorial to defend the space of their family as well as to claim the nearby food.


CHIMPANZE
Chimpanzees live in Africa more precisely in forest and neighboring savannas. The chimps diet is ninety percent vegetarian, although males are known to eat meat more likely than females. Chimps in general have pleasant behaviors as there are very intelligent, although makes are known to be more aggressive than smaller females.Chimps live in societies between 10 to 50 individuals without monogamous mating bonds. Females are constantly moving from communities looking for new mates, these females mate all year long. On the otherside males stick together in their natal community acting as a group defending their resources (food) territories from other chimp communities. Males also perform grooming to each other. Due to their environment and being intelligent chimp males stick together to defend their food and territory from not only predators but also other chimp communities.



Summary
In all the environment of each primate has played a large role in not only survival but also sociology and mating habits. Isolated environments have made major contributions to survival of smaller primates that would no longer be around if they were still living with other apes. Also depending on the type of environment mating patterns have changed to keep the species alive from isolation savannas and rain forest. For the smaller species the environment has given them survival help through large tress in which to spend their time.














Thursday, September 11, 2014

Analogy/Homology

1.     Both whales and kangaroos are mammals and share the homolog of hind legs. Hind legs are the rear limbs of quadrupeds.
 Kangaroos hind legs have developed into quite strong features as they use them to hop around at speeds up to 40mph. Kangaroos hind legs are very large in size and structure. As for Whales, their hind legs are no longer visible but when looking at the skeleton the bones and pelvic girdle are still there, showing that at one time whales walked on hind legs but have evolved into no longer needing them as they spend their life in oceans. Despite the whales not having visible hind legs and the kangaroos have powerful large legs their bone structure still shows similarities to the trait.

Generally the common ancestor of kangaroos and whales was a mammal, as all mammals show to still have hind legs or history of them the ancestor must have also had this trait. Even if you look further down the ancestors, you find that reptiles, which share a commons ancestor with mammals and have species with hind legs and species like snakes that have evolved into not needing their hind legs.








ANALOGY
1.      Sharks and whales both have pectoral fins and some whales also have dorsal fins but these traits are analogous.     

These fins help them maneuver through water with more agility. The shapes while being slightly different in exact outlines still look very similar and work in the same way as the pectoral fins share the same movement.

 For the size of a whale were it not for the pectoral fins it would be extremely slow and as for the shark being a predator it needs to be as agile as possible to catch it prey. If you do go far back enough I do believe that the common ancestor would it be a ocean living specie would have had this trait. The traits are not genetically related because whales are mammal and the pectoral fin is full of bones similar to that of a hand. As for the shark, it does not have a real bone structure as its body is mostly cartilage Whales also being mammals are warm blooded. Marine mammals evolved from being on land to water mammals and in this evolution in order to survive grew fins to better fit into the environment through convergent evolution.









Thursday, September 4, 2014