Earth Day

Well, Earth day was a week ago, so I figured I'd talk about the changes happening on and to the Earth.

Carbon is one of the most abundant elements on the planet.  It is found in everything including animals, plants, rocks, and gas, but it also plays a part in global climate change.  The carbon cycle is a naturally occurring cycle on Eart
h, but humans are throwing the carbon cycle off course by adding more carbon into the atmosphere than it is being removed, causing what is called the "Greenhouse effect".  Humans add carbon dioxide to the atmosphere because of deforestation, causing the carbon to stay in the air because it is not removed by the trees, and also burning fossil fuels adds tons of carbon into the air.  Humans alone add nearly 10 Pgs (1 Pg = 1 billion metric tons) of carbon dioxide into the atmosphere, with no natural cycle to remove it.

Carbon dioxide is a greenhouse gas, which is a gas that absorbs thermal radiation (heat from the Earth) and reflects the heat back to the Earth.  With an excess of carbon dioxide, there is more to reflect back to the Earth, which will heat it.  Through the centuries, there have been several natural fluctuations in the average temperature, but this is the first time it is occurring unnaturally, all because of humans.  Ever since the Industrial Revolution in the 1800's, the average temperature has slowly been climbing.

The Earth is changing because of the increase in temperature, which is causing a huge change in animal life, mainly in the poles because they are experiencing the greatest change.  Many native animals to the poles are becoming extinct, and ice bergs are slowly melting, causing a slight rise in sea level, which can eventually cause flooding.

All the changes happening on Earth seem minuscule to us now, but without changes in our lifestyle, there can be horrible consequences.

Deforestation

Deforestationhas been dramatically altering the Earth for years.  It is one of the leading causes of global climate change and it is drastically changing the natural course of evolution or all organisms.  Humans have all taken part, both directly and indirectly, in destroying forests all over the world. We use the wood from the trees for fuel and building materials and the cleared land can then be used for either agricultural or business purposes, such as constructing unneeded strip malls on all major roads.  Because of deforestation, hundreds on species of plants and animals have either become extinct or critically endangered.  The animals and plants that have neither become extinct nor endangered have been adapted to suit their new lives in there new habitat.  Without the trees and other plants of the forest, the Earth is slowly becoming depleted of much needed oxygen.

                There was once a bird in the family of parrots, the Carolina Parakeet that was native to the eastern coast of the United States, including New Jersey.  It became extinct in 1918 due to the mass deforestation to make room for farms for the new European immigrants.  Because of the loss of their forest habitat, the parakeets turned to eating the crops of farmers, who thought of them as pests and killed them, finishing off the last of the Carolina Parakeet.  

The Greatest Scientific Hoax of the Century.

A missing link to the human evolutionary tree has been discovered.  It was a revolutionary discovery that completely changed the way we look at our phylogenetic tree.  The new creature has been named and placed on the tree where scientists can agree where it belongs,  but it took years to complete because there was so much controversy over the new species discovered, like whether it was real or not.  The human ancestor has caused complete uproar because it was discovered in a highly religious age, creating tension between scientists and religious leaders.  The primitive creature has been determined to exist around 500,000 years ago, long before humans existed and was named Eoanthropus dawsoni, and was given the nickname “Piltdown man”.  It immediately became a worldwide phenomenon. 

Piltdown man was an extremely well thought out hoax, but the mastermind behind it is still unknown. In a quiet town in England in the early 1900s, Charles Dawson, an amateur naturalist, strolled by a quarry and discovered a skull.  He began his research and gained many followers in the scientific community because of this skull and also a few jaw bones and teeth discovered in a nearby area.  Many could not believe Piltdown man was real, so research was constantly being conducted to unveil the hoax, but Dawson became a rich and famous man from his discovery.  Eventually, long after Dawson's death, from the use of modern dating techniques, Piltdown man was named a hoax: the greatest scientific hoax of the century.  

Human Evolution

            The fact that humans once came from “lesser” and simpler animals has baffled many and caused uproar in the scientific and general community alike.  It was once thought that humans evolved in a linear fashion, starting with monkeys, then going to apes, and ending with humans.  But with much research among anthropologists, within the past few decades, it has been decided that we did not come to be so easily.  Humans came from a long line of hominid, or animals more related to humans than chimpanzees are, that struggled to survive and became extinct, leaving humans, one of the only animals to live and be able to flourish on every continent, to virtually take over the entire world.  Everything had to be perfect to create humans as we are today, as one of the only animals with complex social structures and the ability to speak.  

            Along with all these traits that evolved over many, many generations, came the ability to speak, a trait unique to only humans.  Nearly all animals communicate through different ways such as body language, snarling, and high frequency noises like dolphins and whales.  But the development and teaching others of language, and the ability to understand speech through symbols we call letters is extraordinary   

http://humanorigins.si.edu/resources/intro-human-evolution

Piltdown Man

For the Book Review assignment I have been reading "Piltdown Man and Other Hoaxes" by Jonathan Maxwell.  The main hoax discussed is Piltdown man, which was once thought to be a missing link in the evolutionary lineage of humans.

A skull was found in the English county if Sussex in 1908.  It appeared to be closely related to a human's, but the jaw appeared to be very ape-like, and its discoverer, Charle Dawson, hurried home with his find and began some research.  Over the years, Dawson gained many followers who strongly believed Piltdown man was a missing ancestor of humans.  But of course with followers comes those who deny it.  The people against Dawson ranged from the religious community to his fellow scientists who believed this discovery was too good to be true.

Many of his followers were world renowned scientists, so the oppositions against  Piltdown man began to slim, except for the Americans.  American scientists refused to believe that there was the possibility of human ancestors in Europe, but none in America.  At the time, no one knew where humans actually originated (which was in Africa), so there was much dispute among different countries because they all wanted the origin of humans to be from their homeland.  Americans believed humans originated in America, so therefore Piltdown man had to have been a hoax.

Years later, in 1953, long after Charles Dawson passed away, Piltdown man was indeed discovered to be a fraud.  It turns out, the skull of the creature was a human skull and the jaw of an orangutan that were both artificially aged.  They were dropped near each other into a gravel pit left to be discovered.

To this day, the mastermind behind this hoax remains unknown, but many believe it was the discoverer of Piltdown man, Charles Dawson, that forged this "scientific breakthrough".

Hind Feathers and Flight of Early Birds

It is an extremely unknown fact that many dinosaurs and other reptiles possessed feathers to regulate their body temperature because they were all cold-blooded.  However, recent discoveries show that early birds had large legs similar to an ostrich, but their legs did not have tiny feathers, rather they were covered in long feathers that appeared to have been used for flight.  “A bizzare hind wing formed by a large pennaceous feathers (feathers with stiff vanes) along with the metasaurs is known in several non-avian dinosaurs and may have played an important role in the evolution of flight on the line to birds" (Zheng). 

 

Fossils of early birds with strange feathered hindlimbs were discovered and point to the fact that early birds may have had a similar body structure to a biplane, an airplane with two sets of wings, and upper and a lower.  Then, as evolution proceeded, the hindlimbs of birds shrank and lost their feathers.  And their forelimbs grew larder and grew longer and more efficient feathers.  Now the only feathers on the hindlimbs of modern birds are tiny and fluffy and used only for insulation purposes.  

The use of hindlimbs during flight was most likely much easier to accomplish than flying like today's birds.  Without the use of their hindlimbs, it it likely that birds never would have been able to leave the ground.  

            

http://www.sciencemag.org.proxy.libraries.rutgers.edu/content/339/6125/1309.full

Origin of Venom

             Venom is a widely used trait among the animal kingdom.  It has gone through convergent evolution throughout the animal kingdom.  Convergent evolution is when the same trait evolves for the same reasons, but in completely different lineages.
             Many animals use venom either to hunt or to protect themselves from predators.  "Venom is the mark of a special club, a select subset of the animal kingdom. It includes vipers, jellyfish, spiders, scorpions, centipedes, bees, cone snails, newts, platypus, and even a primate" (Zimmer).  Venom is made up of molecules specifically designed to harm another animal.  There are two types of venom, neurotoxins and  hemotoxins.  A neurotoxin is designed to break down the nervous system and the brain, causing a swift death in many animals.  A hemotoxin is designed to break down blood cells and organs, causing a slow and painful death.

 

            All the animals containing venom evolved this unique trait completely separate, but only for two main reasons.  They all evolved venom to either hunt prey or defend from predators.  Snakes, scorpions, and spiders developed venom to both hunt and defend themselves.  The black widow spider has one of the most potent venoms in the animal kingdom, but it cannot inject larger animals (such as humans) with enough venom to cause immediate fatality.  Many other animals like poison dart frogs, puffer-fish, and even some mammals developed venom to protect themselves from predators.  The poison dart frog has a unique, bright colored pattern to warn predators that its skin is highly toxic.

            Venom is a highly unique trait, but it is extremely advantageous to many different animals all throughout the animal kingdom. 

http://phenomena.nationalgeographic.com/2013/01/09/on-the-origin-of-venom/