Lab 10 - Biofuel

     For this lab the class made a trip to Dr. Rood's lab located at the Mercer Law School. After touring around the lab and examining all the various equipment there, we spent the remainder of our time there discussing biofuels. Biofuels are becoming an increasingly common alternative to petroleum products, whether by themselves or in a mixture with gasoline. Specifically, the biofuel that has received the most attention is ethanol. Ethanol is an alcohol and, when produced by fermentation of organic matter, is termed bioethanol. This is the ethanol that is currently being used in mixtures with gasoline. The organic materials that are often fermented to produce bioethanol are corn and sugarcane, but most any organic substance that is high in sugar or starch can be used. The fermentation process uses enzymes to release the sugars, and then the sugars are fermented and distilled. Recently, the top producers of ethanol globally are the U.S. and Brazil.
     Even though bioethanol is an appealing alternative to gasoline, it has its own complications. Even though bioethanol is a renewable energy source, at this point it still requires energy from nonrenewable sources in order to be manufactured. And in many cases, the net energy gain is not as large as could be hoped. Another issue is that, while adding ethanol to gasoline makes the mixture more efficient, ethanol alone does not produce as much energy per volume as gasoline. This means that it would take more ethanol to produce the same amount of work.
     Perhaps more important than both of these is the issue of the material being used to make ethanol. In the U.S., the main ingredient used in the production of bioethanol fuel is corn. This use of corn for fuel instead of food has caused an increase in the price of corn in the U.S. and in the countries it exports corn to. Not only has corn increased but the prices of other crops have as well, as more farmers are choosing to plant corn over other crops. However, several different alternatives to corn are being studied and developed (such as switchgrass), some with hopefully higher and more efficient energy gains, that are fast growing non-food plants. Below is a flow chart that shows the production of bioethanol from sugarcane (in metric units!)

Mitochondrial Eve

     Mitochondrial Eve is the name given in genetics to the common ancestor all humans share on their mother's side. This is because mitochondrial DNA (mtDNA), which is different from normal, genetic DNA, is passed down completely to offspring through the mother without changes or recombination. This means that, theoretically, all humans today share the same mtDNA from their maternal lines. Mitochondrial Eve is said to have lived around 200,000 years ago in eastern Africa, the area where a number of scientists believe the modern human race began to develop and spread from.
     Even though all humans share this common ancestor and have nearly identical genetic DNA, anyone can see that there is a wide range of appearances among people. This is because as people began to migrate into different areas, they would begin to adapt to the regions they settled in. Certain characteristics became more prominent depending on the temperature, elevation, and other environmental factors, but the genetic DNA within the human race still remains very similar on a global scale. This means that this DNA carries the possibilities for all of the different variations in the human race, but that certain genes have become more expressed for one group of people, while the same gene may be recessive or not as expressed in another group, all depending on the environment in which they live.

Lab 9 - Dog Park

     For this lab the plan was for the class to visit a dog park relatively near campus, take some soil samples from the park, and then return to campus to analyze and discuss the samples. However, my section of the class was unfortunately not quite able to make it to park, due to inclement weather. Dr. Rood did bring the samples collected by the first lab section to a regular class period, so my section was able to view some soil samples and what was used to analyze them. Based on what was done, there was a noticeably higher amount of bacteria present in the samples from the dog park than what would normally be found in a randomly chosen area.
     Another component of the lab that we discussed was the importance of dog parks as relates to communities. Dog parks are important to communities for multiple reasons, and have the ability to improve any area that they are found in. They provide a designated place where people can take their dogs for exercise and interaction with other dogs. Inevitably, the owners of the dogs will also be able to interact, allowing for people with common interests to meet and develop relationships around a central location. This is a great help in creating and sustaining a sense of community in the areas where dog parks are located. Below are a few pictures of the dog park in Macon.

Lab 8 - Burgess Shale

     The Burgess Shale is a rock formation located in Western Canada in the Canadian Rocky Mountains, and was discovered in 1909. It is composed of black shale and has become famous for the various, large numbers of excellently preserved fossils that it contains. Below is a satellite image of the Burgess Shale.

      The fossils found in the Burgess Shale are from what is called the Cambrian Era and have been dated to about 505 million years old. These fossils are also part of what is called the "Cambrian explosion", which refers to the relatively sudden increase in the diversity and complexity of the fossils present without any apparent close predecessors. By the end of this event (which was first identified in the mid-19th century), fossil evidence shows that a large number of the phyla that exist today were represented then. Because of the rapid appearance of new, more complex types of organisms without any developmental history, this event was seen as one of the main bodies of evidence against the theory of evolution by its author Charles Darwin.
     To this day the Cambrian explosion continues to serve in that same capacity, having caused (and still causing) much debate within the scientific community, since the theory of evolution has been widely accepted as the explanation of life's origins on earth. However, there is much that remains uncertain about this even due to incomplete fossil records and other difficulties. Hopefully, continued work in the Burgess Shale and in similar formations around the world will continue to provide more details. Below, digital reconstructions of two organisms found fossilized in the Burgess Shale are shown: Opabinia (L) and Wiwaxia (R).

Amphioxus

     The creature amphioxus, also known as a lancelet, is a member of Phylum Chordata and is important to the evolutionary view of the development of vertebrates. It lives in the sands of shallow, temperate to tropical waters where it feeds on material in the water. Amphioxus is seen to be the most basic animal that possesses a nerve cord along the length of their back, a defining feature for vertebrates. They also have the same muscle grouping as vertebrates. However, the amphioxus has no true skeleton, brain, or comparable sensory organs; even though it has gills, they are not used for breathing at all but rather for eating (breathing is done through the skin). Though this small, semi-transparent creature also has many characteristics not common to other vertebrates (like its simpler notochord), current genetic work seems to show that the common ancestor of all chordates had a genetic code very similar to that of amphioxus. A labeled figure of amphioxus can be seen below.

Lab 7 - Hitchiti Experimtental Forest

     For this lab we visited Hitchiti Experimental Forest and did some hiking along the Ernst Brender Trail (the two names are also often reversed). A Google Earth image of the forest is shown below.

     The "experiments" that give the forest its name are done in certain parts of the forest, where periodic controlled burns are done so that the recovery of the ecosystem can be observed and studied. The rich organic soil that is found in much of the forest supports a large variety of trees, mosses, and plants. Two plants in particular that our group took notice of were wild ginger and sassafras. Wild ginger is a stringy, low-growing plant that prefers shady environments and thus thrived in the portions of the forest where there were many large trees (mainly oak and pine) towering over everything else. The leaves, when broken, have a distinct licorice-like smell. A picture of a representative wild ginger is below.

     The other plant that we found was actually a tree, sassafras. Although the specimens we examined were small, sassafras can actually grow to be a medium-sized tree. This tree has had multiple uses for many years, including being used for flavoring, fragrance, (even furniture) and its oil was used once used as a dental antiseptic and pain reliever. But what our group was most interested in was the plant's leaf structure. Up to three different leaf shapes can be commonly found on sassafras, and all three can even be found on the same specimen. The three common types are: an elliptical leaf, and two- and three-lobed leaves. Leaves with more than three lobes occur, but are rare. Pictures of the common leaf shapes can be seen below.

 

And here, all three leaf types can be seen growing on the same specimen:

Lab 6 - Jackson Springs Park

     For this lab the class made a trip to Jackson Springs Park, located in one of Macon's three oldest suburbs. The park was originally part of a larger tract of land (known as Baconsfield Park) that had once also contained a zoo, but much of the land was put up for commercial development. The main purpose of this trip was to be able to find and observe some common rocks and minerals. Items that we brought to aid in this were a magnifying lens and a rock hammer. The hammer was used to break open rocks so that the rocks and the minerals that composed them could be more easily identified. The lens was used to observe (to a degree) the individual mineral crystals and their structure. We were able to find several common rocks such as granite, slate, sandstone and gneiss; we were also able to look at quartz, mica, and hornblende crystals.