Wednesday, February 16, 2011

Large Lake--Fierce Competitors

Lake Malawi holds many secrets in its deep crevasses that reach up to 700 meters. This lake was formed when the plates that make up the earth's crust tore apart in the eastern part of Africa. This tearing of the earth's crust forms areas called rift zones where land is pulled apart and stretches out much like a warm piece of taffy, leaving a thin crust and valley like area in the center with the ends remaining thick. Malawi is located in a particular rift valley called the Great African Rift Valley. It is the southern most lake in a chain of lakes with a surface area of 38,000 square kilometers. As the 8th largest lake in the world and the 2nd deepest lake in Africa, Malawi is home to many interesting and diverse creatures including the aggressive African cichlids that are often kept as pets in tropical fish tanks.

Over a period of a few million years, which is a short time in evolution years, over 22 cichlid species developed with up to 500 individuals in a 50 square mile area. The large amount of different species of the same fish was a result of a process called speciation. Normally, this process occurs when there is only one species of fish, or other animal, in an area where there are many different habitats that can be lived in. In order to reduce competition, or the fight between individuals to get foot or shelter, a member of the species might change their normal preference to fill a new habitat in order to lessen competition. This change occurs over millions of years and eventually the species can no longer mate with the individual that it changed from. Essentially, this is a new species. The cichlid species in Lake Malawi live in an area called the littoral zone which is characterized by a rocky bottom, plant life, and shallow water. The interactions between species, also called interspecific competition, is often studied in these waters in attempt to discover how they partition the habitat for maximum resources.

A process called niche partitioning is often accounted for as the main reason why the diversity of cichlid species has been maintained. Niche partitioning is when members of similar species inhabit different types of habitats in order to lessen competition. It has also been argued that the speciation event of this fish occurred so quickly that members of different cichlid species act as equal. In reality it has been observed male cichlids in Lake Malawi actively guard three different types of territories from different types of other cichlids. The first territory that is guarded by the male is the feeding territory which is characterized by areas where algae and microbes are attached to rocks. Males guard this territory against many fish of their species and not of their species that feed on similar foods. The second territory is the mating territory. A male will actively and aggressively guard this territory from males of the same species and attempt to attract females of the same species while allowing any species of cichlid to travel through this area as long as they have a different diet. The spawning territory is the third and final territory and it is also the smallest. The male will not allow any fish, whether it be a male or female from the same species, to enter this territory in fear that the area will be jeopardized for future spawning activity. All of this information on African cichlids is just a small piece of the story of and I challenge you to go out and research more!

Snottites are AWESOME!

Cueva de Villa Luz, an extremely interesting cave in Tabasco, Mexico, has piqued my interest in light of a short segment of Planet Earth that we watched in our Limnology class today. Before today I had never heard of this cave before. In actuality I had never heard of anything like the biology and ecology of this cave and the way it works. The water flowing through this cave is acidified by sulfuric acid produced by many different kinds of bacteria that form “snottites” throughout the cave.

After hearing the term “snottite,” I was very curious as to what type of bacteria could be forming these sulfuric acid producing snot-like things hanging from the ceiling of the cave. The snottites are stalactites made out of bacterial goo. Hydrogen sulfide, a very poisonous gas leaked up through oil deposits deep in the bottom of the cave, is utilized by these bacteria as an energy source. These bacteria produce the sulfuric acid as a waste product. (The types of bacteria that are found in these snottites are part of a group called the Eubacteria.)
The sulfuric acid then drips down from the snottites into the water below them which in turn acidifies the water. Because of the acid being leaked into the water, the cave is generally more acidic than most other cave environments.

So, besides acidifying the water flowing through the cave, what other uses do the snottites have? The snottites provide a food source for many fish and other insects that live in the cave. One insect in particular that uses the snottites as a food source is the midge that lives in the cave. The midges lay their eggs on the snottites so that the larva can use the bacteria as their main food source.
The acid produced by the snottites also helps to shape and reshape the cave, producing more habitat and changing the form of the cave bottom. So in looking at the bacteria in the snottites, there have been many discoveries about the functionality of these complex bacterial interactions with not only the rock but also with the organisms living in the cave.;col1

Tuesday, February 15, 2011

Agricultural Ants

     Imagine just for a second that someone dropped you in the middle of the rainforest with no directions, no food, nothing. How would you find your way out or even find something to eat? There might be some edible things nearby, but once you set off who knows when you'll find food again. Now imagine you were an ant on the rainforest floor. It would seem even bigger and be even harder to find food. There doesn’t appear to be many options; you could stay in one place and starve after you run out of food, you could set out and hope you stumble upon a new source of food, or you could…start a farm?
     Well, that’s what the ant species Atta cephalotes did. It may seem hard to believe but they actually beat humans to agriculture by about 50 million years. Just as the development of agriculture lead to a more stable food supply for humans, these ants ensure they will have something to eat by "farming" fungi. Agriculture allowed humans to stay in one place for a much longer period of time before their resources were exhausted and the same is true of these farming ants. Instead of spending huge quantities of time foraging for food (while under threat of predators), these ants spend time cultivating fungi to eat.
      I’ve given you the what and the why, so now for the how. While humans are sweating in the garden pulling weeds by hand or choking on pesticides, ants actually secret a substance which kills weed molds that have invaded their crops. Along with weeding, these ants also fertilize their fungi to increase their harvest. New research has also found that fungi-growing ants have updated their crops over time. DNA analysis has shown that one species of these ants dates back 12 million years while the fungus they grow is from just 2-3 million years ago. This evidence shows that these ants update their crops over time for maximum benefit, just as humans have done.

Wednesday, February 2, 2011

Is the Chesapeake doomed?

Do you have any idea how drastically different many states would be if the Chesapeake Bay did not exist or if it were completely destroyed? There are so many different types of organisms that only live in the Chesapeake and that depend on the world’s largest estuary as its sole environment to live in. (In case you don’t know what an estuary is, it’s where freshwater meets saline ocean water.) The Chesapeake also produces many ecosystem services for the area. It is a major breeding ground for many different species and is also home to many economically important species such as the blue crab.

Over the past few years, many different agencies and organizations, such as the Environmental Protection Administration and the National Fish and Wildlife Foundation, have been trying to do their best to educate the public about the importance of the Chesapeake Bay. They also have been trying to find new ways to take care of the bay and to bring the estuary back to a better state. The drainage basin of the Chesapeake Bay is so large and it would be hard to efficiently get the word out about the importance of its services. Wouldn’t it be terrible if we lost all of those tasty blue crabs that live in the Chesapeake Bay??

Is there anything we can do to fix the damage that we have done to this important ecosystem?? Recent studies funded by these various organizations have been trying to find different ways to clean up the bay and ways to help take some of the extra nutrients out of the system. One study was using oysters to try and filter out the nutrients from the water. They found that the larger oysters were very efficient at filtering out various nutrients that were overloading the water. They found that these oysters were capable of absorbing large quantities of nitrogen, phosphorous, and carbon from the water. With the help of these oysters, the Chesapeake Bay could possibly be on the right track to getting back to a more stable state.

I don’t think that these oysters have been introduced into the bay as of yet but the capabilities of the oysters have been studied in hopes that they will be able to have a positive effect in the system. I wonder what other organisms could be introduced into that system to help clean up the area…

I tried to use questions throughout the post to create a sort of hook and to get people thinking throughout. I also tried to use less technical language and explained the terms that I thought could possibly be confusing. I also tried to catch the reader’s attention by including some pictures that I hoped would not only break up the text but also give the reader something to look at. The pictures help the reader to relate to what I am talking about.

Tuesday, February 1, 2011

Why Do Penguins Have Wings if They Don't Fly?

     Although they can get some "air" when coming to shore or swimming at high speeds, penguins can't fly in the way we traditionally think of birds flying. But even though they can't soar through the air, they put their wings to good use when they're in the water. I think the author of the article in Science Now says it best: "Penguins can't fly, but don't feel sorry for them." They use their wings to propel themselves through the water, diving for up to 7 minutes and to depths of 300 meters!
     Paleontologists have been examining penguin fossils to determine what the ancestors of today's penguins looked like and how their swimming capabilities developed in a group of animals distinguished by flight. Julia Clarke and her team found a complete fossil dating back almost 36 million years ago. Clarke's team determined that this species of penguin (Inkayacu paracasensis) probably wasn't able to dive like modern penguins but that it was able to swim on the surface. Melanosomes, which are cells containing the naturally occurring pigment, melanin, are preserved in fossils. This allows researchers to determine the color of the animal in question. After examining the melanosomes from the fossil, the team determined this penguin most likely had gray or reddish-brown feathers. This may not seem like a big deal, but having black or dark brown wings is an advantage to penguins. The darker coloration occurs with higher concentrations of melanin which may also increase the strength and rigidity of penguin's wings. It appears as though having more melanin is at least one of the adaptations allowing penguins to become the skilled swimmers they are. However, one expert wonders why penguins aren't completely black if melanin is such an advantage. Another says that the black on white coloration provides camouflage. Perhaps this coloration gives penguins the "best of both worlds" so-to-speak; they have the strength of melanin as well as a white underbelly that is less distinguishable to predators in the depths. What do you think?

I tried not to use too much jargon or uncommon words to keep the flow of the article going and also to prevent readers from becoming frustrated or confused. I included pictures to break up the wall of text; I know that I am much more likely to read something if there is a picture. I tried to "arouse and fulfill" by having a question as the title of my post, in the hope that readers would then want to learn more about penguins and their wings. I also tried to stay in active voice and explain things with enough, but not too much detail.

Pokemon aren't the only creatures that Evolve

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Next time you think of germs or bacteria as being so simple, think again. For many years, scientist have believed that only complex organism have the capability of going through evolution. A blog titled "Gene Relocation is Key to Most Evolutionary Change in Bacteria" shows that this is not necessarily true. The author uses a new study, published by the University of Maryland and the Institut Pasteur to help prove her statement.

Environments are always changing and creatures have to learn adapt to these new environments otherwise they die out. What living organism can be found in almost any environment…BACTERIA. That’s right, run and hide….well wait you can’t hide. That’s because they are everywhere ranging from incredibly cold to extremely hot. Do you know what makes these little boogers be able to do this? If you said gene duplication within the same organism, your wrong; if you guessed evolution then you are correct. YAY!!!!!!!!!!!!!!

It is not the typical evolution though, bacteria help each other evolve and be resistant by passing on genes to each other. This is called horizontal gene transfer. You don’t believe that this is evolution? Well, how would you survive if humans never learned how to communicate with each other and taught each other how to deal with certain problems. Maybe humans are not as unique as what we like to think. Bacteria has learned to adapt to so many different environments by sharing information with each other and then passing that to their “offspring”. If the bacteria did not receive help from other bacteria then it died. This, in a sense, is a form of natural selection and natural selection is a part of evolution. So, you better be nice to those microbes under your foot and on your hands because who knows, maybe they will evolve and try spaying you with bleach.

As a reflection of this article, I caught the attention of the readers by first having that picture (which, in my opinion was funny). I then kept the readers involved by asking them questions and making them think. The use of the questions also helped to provide mental images for the readers. The sentence structure and paragraphs flowed pretty nicely, in my opinion and the blog as a whole seemed to keep flowing.