Total Pageviews

Wednesday, November 19, 2014

Hoax Revealed

In the Early 1900’s the first skull fragments were discovered  and then later in 1912 publically announced as Piltdown Man to the Natural History Museum. This was accredited to Charles Dawson who invited Arthur Smith Woodward and Father Pierre Teilhard De Chardin to support his discovery. This was significant because Piltdown Man theorized that it was an evolutionary path that associated apes and humans closely together. Another member involved in the Arthur Keith an anatomist that once opposed the remains authentication, changed his opinion and fully supported Piltdown Man when it supported his theory that large brains came before walking upright in the human evolutionary path. The remaining fossils were uncovered four years after the public announcement and death of Charles Dawson. Within the decade of Piltdown Man last discovered remains ancient human fossils were found in Asia and Africa and less human looking in appearance some were discredited due to the fact that they did not follow the evolutionary path of Piltdown Man.

The reconstructed skull of Piltdown Man was one of male skull fragments and the altered lower jaw bone and tooth of a female orangutan. The jaw bone was purposely broken to remove the tell-tell sign that the jaw was not human and the back teeth were filed down to resemble human molders, the staining with potash gave the fossil the appearance of being older and the tooth also filed down was painted to resemble aged remains. Piltdown man was later proven to be a hoax due to cutting edge test however the hoax lasted for 40 years some of which were scientist were not allowed to conduct test even as new discoveries gave evidence to question the integrity of the remains (first and last remains were discovered by Charles Dawson and none were found after his death, 1975 the trunk belonging to Martin Hinton of artifacts with chemical staining and filing down proven similar to Piltdown Man). 
              
The human fault in this scenario or any scientific discovery is when artifacts are altered to prove theories and integrity of the discovery is not objective (egos and pride). The Piltdown Hoax was a discovery that temporally changed the beliefs our evolutionary path and discredited other discoveries because they were different from Piltdown Man. This error in history lasted 40 years until accurate test were developed and allowed to be administered on the remains of Piltdown Man. The falsification of Piltdown Man was a mystery that was questioned but never really remarked on at the time, even when older authentic remains surfaced in other parts of the world.

Positive aspects of science are that test can be improved with time. The test that confirmed the hoax of Piltdown Man were a drilling test that revealed the skull fragments were odorless clearing them to be older than the lower jaw bone. The lower jawbone contained a burning scent that only occurs with fossils that are younger (like fresh bones). This test disproved the assumption that the skull fragments and jaw bone are from the same specimen. Another test was the fluorine absorption test performed in 1949 by Dr. Kenneth Oakley (the longer remains are in ground the more fluorine they can absorb from the soil) results stated that the skull fragments were much younger than estimated (500,000 years old) and the jaw bone was younger than the skull and from a female orangutan. Test in 1959 (carbon-14 dating technique) confirmed by Joseph Weiner that the skull was 520-720 years old and jaw centuries younger. The Acid Test where hydrochloric acid applied to the fossils rubbed off the staining color caused by  potassium dichromate.

I’m not sure if it’s possible to take the human factor out of science completely, so that past errors like Piltdown Man won’t occur again but I think several precautions are in placed because of events like this. Scientists can keep detailed documentation, record all interpretations/speculation, review with specialist and re-check results several times but in the end we are all just human. It’s common nature to over-look things and change a thought during a discovery and have an ego. I’m on the fence about whether I would remove human factors from science as a whole because we may produce errors on occasion but we’re persistent about proving our findings true but without unbiased evidence and mindset errors are bound to happen.

This makes me want ten forms of confirmation that something is accurate. That amateur in the field should review  with established scholars or scientist on findings because this event can really open your eyes to bad/good research and methods. I have never really heard of this particular event in history perhaps due to the huge discredit it received. This assignment has made me cautious and curious of discoveries and how objective methods are key in the science process.      

Thursday, November 13, 2014

Comparative Primate Blog Post

Lemurs
Lemurs are a unique primate that is perfectly suited to live on the vast terrain of Madagascar. Just 250 miles off the east coast of Africa this environment is lush in tropical vegetation, marshlands, dry forest, deserts, and beautiful coral reef surrounding the island. With endemic plants that are rarely seen anywhere on earth like rare species of orchids, Didiereaceae (makes up the spiny forest) palms and baobabs. Lemurs and other animals along with vegetation have been able to flourish in this area because of its isolation for so long. Major predators are not native to the island and this allows smaller mammals like the lemurs to thrive and feed on the vegetation (herbivore).


The body size of the lemur is small (pygmy to average cat size) which works it perfectly since it’s arboreal in trait and rarely on ground level. The sexual dimorphism is low and males are slightly bigger here and there but not by much. A more noticeable distinction is the sexual dichromatic instead of an overall size difference (sexes are different as seen in their fur coloration) like in birds and insects. Lemurs are also not male dominant but a female dominant society. 


Spider Monkey
This unique monkey has several species that can be found in tropical jungles from South and Central America. Tall hardwood and softwood help provide housing for creatures like the spider monkey and local vegetation hides them from predator. For an arboreal animal living in the high canopy is best because food as well as water source is plentiful and other animals like small reptiles and insects complete the omnivorous diet of the spider monkey. Troops are the group name for spider monkeys and rather that a male searching for a new group to join, the female is the one seeking a new troop to look for a mate.
 Depending on the species, spider monkeys can reach vary in height and weight, but the sexual dimorphism seems to be low overall so both male and female seem similar in size and shape. Generally smaller primates are equal in size to their mate and tree dwellers while larger primates need the size difference to protect their mate from dangerous  predator that share the ground with them.


Baboon
Old World Monkeys or baboons have five species and can be found traveling in troops within the different regions provided by their habitats in Africa and Western Arabia.  Baboons are relatively adaptable as they can be in the dry savanna, woodlands and tropical rainforests. The different regions provide shelter and nourishment (Fruits baring trees, seeds, small animals and eggs) for the yellow, olive, guinea, chacma, and hamadryas baboons. Depending on the species the sexual dimorphism can vary but primarily the overall result is that males are larger than females in size and canine development. Males are the dominant of the sexes and can be 31in in length weighting 40-66lbs whereas the female 18in overall length weighting in 20-30lbs and tails add on 16-18ins to both male and female (example hamadryas baboons.)
The body size between the sexes is important because baboons live in hierarchical troops. Baboon harem consists of 4-6 females and young with a dominant male and larger troop of 50-200 with a mixture of females ranging in ages with dominant males as hunters and protectors. Baboons are terrestrial animals and larger males are needed to protect the females and young within their groups as they forage for food. 



















Gibbon

Gibbons are small ape species (small or large based on the genera) and like the baboons are omnivores (eat plant and animal matter). Gibbons can be found in tropical rainforest of Southeast Asia as well as neighboring countries like Thailand and Malaysia. The typical rainforest gibbons live in includes over 2,000 vine vegetation throughout the forest, moderate rainfall, and high canopies that let in a small percentage of sunlight. The majority vegetation overall in rainforest are 70% different trees like with hardwoods (), baobab, coconut, and even some of the tallest tree species tualangs. Diverse tree species are ideal for gibbons as they are arboreal in nature meaning they spend nearly their entire lives within the upper canopy and emergent of the forest. This provides them with shelter, nourishment, even protection from predators like leopards larger snakes, etc.

Slender bodies and elongated arms, no tails and smaller physique make them agile in tree tops. And with their sexual dimorphism low they are almost equal in height and weight. Gibbon troops consist of territorial male and female mates and their offspring which they equally care for until the young are able to start a family of their own. With fewer dangers to the Gibbons as they are high in the canopy the need for a large protector isn't as defined as in Baboons.



Chimpanzee
Chimpanzees are part of the Great Ape family (like humans and gorillas) and are intelligent for the use of tools from rocks/forest materials and cognitive thinking. Chimpanzees are omnivores because they eat both meat of smaller animals and vegetation. Chimpanzees can be found in dry savannas areas (with shrubs and isolated trees and open canopy), different forest terrain (evergreen, swamp) and dry woodlands of Central and Western Africa (equatorial forest “belt”). They are both terrestrial and arboreal in nature, generally on the ground however they built nest of vegetation in trees while they live in social communities.

The sexual dimorphism is minor as the males are slightly bigger than the females. Males can range from 90-115lbs whereas females are 57-110lbs and half a foot smaller than a height of 4-5 ft. (males). Chimpanzees live in multi-male and multi-female social groups, status can be solved with sexual dimorphism an alpha must be bigger and therefor stronger to protect and have the right to mate. And because they are primarily on the ground knuckle walking predators have a better advantage to attack then those of solely arboreal trait primates.







This assignment have been very interesting I'm sure I forgot things but hopefully I included things unique about these five primates and how they have adapted to their environment even with outside causing harm like deforestation, pollution, and hunting. Smaller primates were generally arboreal and didn't need a show of force because the areas they lived in secluded them more from predators. (Larger primates) because of their size, were more terrestrial and  males more dominant and larger to ensure the safety of group members as well as potential mates. I like that the primate groups socialize and make bonds as they groom, travel and live together as well.   


Friday, November 7, 2014

Analogy/Homology Examples

1)      Two species that contain homologous traits.
a)     Horses and Shrews (the different species with homologous traits)
b)     They even have the same bone structures in the forearms:   humerus, ulna, radius, carpals, metacarpals, and phalanges. The functions of these limbs are different; the horses use this for walking, galloping even sleeping upright. The Northern Short-tailed shrew uses these for crawling, grasping things and even defense.
c)      These animals both part of the mammalia (mammal) class, similar habitats like grasslands and forests. The shrew unlike the horse has many predators and another difference is the horses are herbivores and shrews are carnivorous.



Lastly two species that have Analogous Traits.
Human and octopus 
• Octopuses are Cephalopod and humans are Homo Sapien Sapien. Their eyes have the same eyelid, cornea, pupil, iris, ciliary muscle, lens, retina, optic nerve and optic ganglion. Both carnivorous animals and both part of the Animalia kingdom but unlike our eyes these creatures don’t have a blind spot and have heighten abilities like seeing in the dark to live whereas human eyes need light to observe and survive.