Trip to National Museum of Natural History:David H. Koch Hall of Human Origins

For my second field trip for the Science and Global Change Scholars program at UMD, I visited the National Museum of Natural History. I visited the Museum located in Washington, D.C on March 28, 2010 with a large number of other Scholars students. The Museum had received a new exhibit called the David H. Koch Hall of Human Origins on a few weeks before on March 17th which became the focus of our field trip. We also visited two other Paleontology halls called Early Life and Fossil mammals. The early life exhibit discussed the origins of life and a majority of the Earth's History. The fossil mammals exhibit displayed North American mammals specifically those in the West during the Cenozoic era.

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Coming in from the Oceans Hall we came to find the fossil of "Lucy" in the Hall of Human origins. The 3.2 million year old human like skeleton of Australopithecus afarensis was located in modern Ethiopia. In this site in Ethiopia Called "Hadar", Lucy's skeleton was found. Lucy was thought to climb trees and walk upright in a grasslands environment along with shrublands and forests. The climate she lived in was cool and wet with evidence coming from Fossil Pollen and animals. The fossil pollen showed evidence of cat tails which are found in wet environments and Juniper trees which are found in cold humid forests. The fossil of animals analyzed in the Hadar site showed jaws of wildabeests relatives and extinct monkeys. The wildabeest jaws had many teeth designed to chew grass let you know that Lucy lived in an forest or an area with lots of grasslands. The monkey jaw with its teeth let people know that there were monkeys eating leaves in trees meaning the area had trees with sufficient foliage to sustain monkeys. The changes over time that were represent showed that around 2.95 million years ago there were woodlands that turned into dry grasslands and then back to woodlands about 3.2-3.28 million years ago. Then 3.35 million years again it switched to a forest and then became a wetter environment 3.4 million years ago. The evidence is seen in dating the fossil remains of the animals and plants in the excavation site in Hadar.

Physical changes in Hominid evolution morphed the human body into what it is today. Becoming bipedal changed many parts of our body. The sahelanthropus species is the earliest known to have walked bipedally about 6-7 million years ago. Becoming bipedal led to evolution of heads in the body where the spinal cord entered the skull closer to the center become more balance on the body. Leg support was also brought on evolution making the bridge from the thigh to the hip stronger allow them to support their body weight better as seen in the Orrorin tugenensis fossil dated to 6 million years old. The knees in hominids also became wider below the area of the early human's knee joint allowing stress on the knee to be handle in greater quantity. A curved spine emerged about 2.5 million years ago in Australopithecus africanus allowing that species to greater absorb the shock of walking. Changes in hip structure came after a curved spine with changes to the size and broad shape of the hip demonstrating a change from climbing to walking. Longer legs were the last step that occurred about 1.89 million years ago when femurs become longer to allow greater stride lengths to walk and run faster. Becoming fully bipedal allowed hominids to travel greater distances and run faster giving them an advantage of smaller prey. They could now travel greater distance to find food and chase down faster animals for meat.

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During this portion of the hall I focused on the "New Tools, New Foods display" showing the changes in technology that led to changes in diet. The display showed that the control of fire led to many advantages for early hominids focusing on their diet. With the advantage of fire they had improved digestion through cooked meat and could now remove poisons and nutrients by cooking their foods. Other new technologies in the form of new tools expanded the diet of early hominids as well. They could now use spear throwers and harpoons to hunt previously a greater variety of animals from ancient catfish to large mammals from their bone and arrow head tipped spears with throwers. The lures and hooks used today would pale in comparison to large bony and barbed spears and hooks used by early hominids. These new technologies allow humans to hunt animals that could feed many people a day and get quick energy. However the costs of hunting for meat came from the danger of hunting dangerous animals and the fact that meat spoils quickly.

In the section describing the Anthropecene Event of the Changing the World section I first looked at transformation of Earth's natural landscapes. Humans began to control growth of certain plants and animals changing the natural process of vegetation and animal growth. Crops began to cover a fourth of the earth surface and farms began to emerge. Animal populations exploded from farms growing cattle, pig, sheep and goats. The exhibit designers showed this through a timeline graph showing when certain plants came to be used as major food sources along with cases showing the number of animal populations with animal figures in cases to show the population of animals. They also had a graph showing the human population increasing next to the crop growth chart to parallel certain factors. I then moved to a displaying showing the rise of earths CO2 levels. The displayed showed that the earth's Temperature and CO2 levels fluctuated together associating higher CO2 levels to higher Temperatures. Rising sea levels and melting glaciers are the product of the temperature changes. The display showed evidence of past CO2 levels by showing the drill cores from Antarctica where the CO2 air bubbles became trapped in Ice. The display also pointed out that today's CO2 levels are the highest its ever been and in the next century the project increase is double of what its been in the past 6 million years. The third display I looked at was the unintended consequences display. The designer had a display case with glass models of many different types of bacteria and viruses. The displayed showed the numbers of people dying from cholera and flu each year. It also went on to add that a child dies from malaria every 30 second and 40% of the world's population is at risk. The display explained that the population growth led to closer living quarter leading to increased numbers of disease in the human population.

The gallery on early life discussed the origins of life and the first 80% of Earth's history where humans were nowhere to be found. The early atmosphere had only small amounts of oxygen because plants were not as common which could produce oxygen through photosynthesis. The gallery showed that photosynthesis transformed the earth atmosphere at it took the CO2 from the atmosphere and converted it to oxygen. The Early Earth's atmosphere was also rich in CO2 levels making it great for plant growth as plants require CO2 and sunlight to grow. The gallery displayed info suggesting that meteorites brought components necessary for life to form on earth that was not present in the atmosphere. The Stromatolite formations composed of algae and bacteria shows that oxygen was present and forming as the algae and bacteria created oxygen.

The fossil mammal hall showed different mammals of the Cenozoic area in Western North America. The environmental changes that occurred during this time came from the climate continually cooling and becoming dry. Grasslands spread and covered Western North America that led to changes in mammal life. The Miocene animals changed to eat more grease and move with more speed to cover the vast grasslands. This can be seen through the changes in Horses biological systems. The bacteria called "Runnon" allowed mammals to digest cellulose more efficiently and extract more nutrients from plants. Another example of evidence is seen in the longer limbs of mammals. The longer limbs allow horses to travel open grasslands with greater speed and ease.

The hall of human origins had many great displays, but the ones that really struck me were the New Tools New Food, the Biological adaptations, and the exhibit on Lucy. The New Tools, New Food exhibit had all the early weaponry and tools that early hominids used like the harpoons and spears throwing tools. They also had tools that monkeys would use to extract ants and stab bush babies. It was an interesting comparison to see how early hominids used tools and the primates of today. The tools we use today have come a long way in that we can kill animals from a mile away and stay out of harm. Also the display focused on fire and how it allowed us to cook food and remove poisons from certain plants. The video playing in the exhibit showed how arrowheads and tools were made from flint stones. .The tools portrayed the idea that the new tools allow hominids to vastly improve and expand their diet. They could now hunt animals that other hominids could have never done. The primitive tools were effective in showing this concept as it also informed us on how the animals hunted like giant catfish could feed many people in a village allowing for things like specialization to occur. The biological adaptation exhibit went through different adaptations that hominids went through. They dealt with the evolution to a bipedal mammal. I had originally thought that a few hominids had started to walk on two legs and eventually our muscles came to support the added stress. It was a large step and took millions of years of become fully bipedal. We started standing upright which changed our skull shape then our spine, hips, and legs making us fully bipedal. This displayed show that evolution takes a large amount of time and comes in small steps. The display was effective in doing so as it showed all of the steps to become fully bipedal mammals showing that it was not simple as standing up on two legs. The display on Lucy showed an example of her skeleton and then a display of what she would have looked like her natural environment in a display case. The display showed evidence of how they came to find about the environment she lived in with fossil remains. The display of what she would have looked like put her in a forest like environment and put hair on a small 3 foot human like body. The whole display was demonstrated all the evidence that was found in Hadar and demonstrated how they came up with a depiction of Lucy. The exhibit showed how scientists came up with the info on Lucy and did it quite effectively. It displayed all the evidence and then put it together with a display of Lucy in her natural environment.

Bibliography:

Edwards, Lin. "New Species of Early Hominid Found." PHYSORG, 6 Apr. 2010. Web. 6 Apr. 2010. http://www.physorg.com/news189771175.html

This article discusses a new hominid species that was found in South Africa. This species is about 2 million years and could possibly be see another transitional species between hominids and human ancestors. The species is thought to be the one in which stone tools were emerging and climbing trees was no longer the norm. The findings of this study are to be revealed tomorrow. This is similar to the hall of human origins exhibits displays as it shows a skeleton like Lucy's and goes on to describe what kind of life this species lived.

Vullo, Roman, Emmanuel Gheerbrant, Christian Muizon, and Didier Neraudeau. "The oldest modern therian mammal from Europe and its bearing on stem marsupial paleobiogeography." PNAS. Ed. RichardCifelli.6,Nov.2009.Web.6Apr.2010.http://www.pnas.org/content/106/47/19910.short

This article discussed the discovery of mammalian teeth in Southwestern France that is a new marsupial like species. It shows a resemblance to many of the North American marsupials showing that marsupial forms existed in ancient Europe a place once thought to have no marsupial forms. This relates to some of mammal species we saw in the fossil mammals exhibit in that there were marsupials that crossed continents and existed in two different hemispheres and were quite similar.

Submitted on April 6, 2010