Extreme Biology

by Ali

In Biology we recently did a dissection on the Dogfish shark. This lab was one of the most interesting because we were paired in groups of about four people and we would get our own shark to dissect and observe. In doing so we observed multiple things such as the incredibly large liver compared to the shark’s size. As we were dissecting we learned that the liver in fact provides buoyancy to the shark to help it not sink in the water. In this website it shows a diagram of a shark and explains in detail the structure and functions of the following: skeleton, muscles, digestive tract, circulatory system, gill and respiration, and the liver. An interesting fact as I was researching the dogfish shark was provided on this website and it stated that it was in fact the most common shark found especially in the North Atlantic Ocean.
 
What did you learn from this lab that you were not initially aware of about sharks? What other adaptations in structure did you find on the shark?  Did you discover any other interesting facts on sharks as you were researching?

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by Connor

For years movies like Jurassic Park have fascinated us all. The idea of bringing back a dead or extinct species is fantastic. But the real question still remains: Can it be done? According to scientists it can be done, thanks to a new found mammoth carcass. In today’s world, scientists are trying to clone or reproduce live wooly mammoths. One organization in Japan has been working on this since 2005, and recently a documentary has been shown on this very subject. It’s as real as it’s going to get.

But to clone a Mammoth you must first go through a very rigorous process. First you must get the egg of an elephant (this would be the easiest way). Then you must fertilize the egg by either using a mammoth sperm, or by getting full mammoth DNA. It’s very complicated and if you would like to learn more visit this website.

Here are some facts about mammoths. Mammoths, African, and Asian elephants evolved from the same ancestor. The woolly mammoth was only about 11’ tall, whereas its predecessor, the Columbian mammoth was 13’ tall. Mastodons did not evolve from the same ancestors, but rather branched off immediately after the first elephant-like species died off. To learn more about the mammoths visit this site.

All in all I think it’s pretty cool what they’re doing with these mammoths. I hope that they can someday clone extinct animals, because it could help in studying animals on earth today. Here are some questions you might want to ask yourselves on the subject:  Would you like to have a woolly mammoth in your zoo? Would it be safe?  Would you like to have one as a pet? Would you think it would be dangerous?  From a religious and/or scientific view, is it right to clone dead or extinct animals?

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by Sydni

A simple fungus, that quickly deteriorated the fibers in WWII tents and uniforms, has now been discovered to be very efficient and cost effective in the creation of ethanol, a fuel alternative to gasoline.  Ethanol is created from fermented simple sugars that are found in natural substances such as corn and switchgrass.  Recently ethanol has been criticized by many to be an expensive and inefficient fuel alternative. The fungus, Tricoderma reesei, on an industrial scale, could revolutionize the process of producing ethanol.

T. reesei breaks down human-indigestible planet fibers through enzymes to create monosaccharide, the simplest sugar form, which it uses as food.  When researchers tried to figure out why it was so efficient at processing plant cells, they discovered a way it could help revolutionize the ethanol production process.  The discovery stemmed from mapping the genome of T. reesei.  They found, while there were large quantities of enzymes, there were fewer variations in the types of enzymes produced.  Scientists concluded that the system must be extremely efficient in releasing the proteins which create simple sugar plant fibers.

By adding purified T. reesei enzymes to a mixture of cellulose pulp and other materials, sugar is produced, which can then, with yeast, be fermented into ethanol. “The sequencing of the Trichoderma reesei genome is a major step towards using renewable feedstocks for the production of fuels and chemicals,” said Joel Cherry, director of research activities in second-generation biofuels for Novozymes, a collaborating institution in the study.

“The information contained in its genome will allow us to better understand how this organism degrades cellulose so efficiently and to understand how it produces the required enzymes so prodigiously. Using this information, it may be possible to improve both of these properties, decreasing the cost of converting cellulosic biomass to fuels and chemicals.”

This fungus can revolutionize the way America produces an earth-friendly fuel alternative, more efficiently and more cost effectively than gasoline.

Do you think it important to find alternative fuel sources for a better future?  Do you think this fungus could be one step toward creating an effective and efficient alternative to gasoline? Why?

by Lauren (AP Biology)

Evolution is arguably the most central theme in biology because it ties all other major themes together. Evolution is defined as a change in alleles in a population over time. In each level of life, there is proof of evolution on a population through natural selection on individuals. Darwin, credited as the founder of evolutionary theory, made four main points in his book that described how it works:

1. Each species produces more offspring than can survive.
2. These offspring must compete with each other for limited resources required to survive.
3. Organisms in all populations vary in alleles and are different.
4. The individuals with the most favorable traits or variations are the most likely to survive and therefore produce more offspring.

Molecular
Genes are the units that help code for proteins within an organism. Evolution has seen the selection of specific genes that code for specific proteins over less desirable genes. For instance, the gene that codes for blindness in the blind cavefish is chosen over the gene for eyesight. The reason for this is that one of the two genes involved in senses of the fish must be traded for the others. In easier terms, the eyesight of the fish must be sacrificed so that the jaw and taste buds can develop. In this case, the pleitrophy gene that controls this development is slightly inhibited by another gene. The only reason the inhibiting gene is selected is because while it inhibits eyesight, the fish can rely on its other sensory organs, which proves to be successful.

Cellular

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On a cellular level, eukaryotic cells are complex in comparison to prokaryotic cells. According to the endosymbiotic theory, the evolution of organelles originated from a prokaryotic cell that joined with separate prokaryotic cells. The organelles in the cell proved to be exceptionally helpful, such as the mitochondria, which supplied it with energy. The earliest mitochondrion is believed to have begun as a very primitive bacterium. With a source of internal energy, the eukaryotic cell was more favorable and through natural selection, became more frequent.

Organismal

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The kidneys are responsible for filtering the wastes of the blood and reabsorbing nutrients during the process. Some animals have evolved to have excretory systems to compliment the environment that they live in. For instance, in dry and arid environments, many animals have an extra complex collecting duct, where the most water is reabsorbed during excretion, to maximize the amount of water conserved. Those organisms that have the systems to do this can survive longer and are favorable to the environment because of their success in retaining water, which is a necessity in their environment.

Population

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One of the easiest examples to observe since it reproduces so quickly, bacteria helps explain genetic drift in populations. If you were to put a culture of bacteria in a nutrient rich environment, they would reproduce. But if you added an antibiotic into the environment that killed most of the bacteria, only the bacteria that had alleles that made them resistant to the antibiotic would survive. Since the bacteria that died did not have a high fitness, they were not able to continue contributing their genes to the pool. Only the surviving bacteria will be able to pass on their genes, which include resistance. This, in time, will lead to a whole generation of antibiotic resistant bacteria that has evolved from the original population to one made of resistant genes.

Community

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The predators and prey evolve together, the prey trying to stay one step ahead of the predator, and the predator trying to catch up. In the case of wolves and rabbits, wolves evolve mechanisms to help them survive by obtaining food such as speed, stealth, camouflage, and excellent sensory senses. Likewise, the prey, rabbits, develop similar mechanisms to aid in avoidance and escape of a predator. Any trait such as long legs to run or hop faster will enable the prey to escape its predator, and pass its genes to its offspring. Those that are eaten obviously were not fit to their environment and their genes, which did not help them, will not be passed on.

Biosphere

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The globe is made up of many different climates and geographic features, each factors of a specific biome. With in a biome, an ecosystem of organisms exists which specifically suit that particular biome. Producers within the biome have evolved features that give them high evolutionary fitness. The consumers that feed off of these producers are also well suited to their biome, as discussed in population. With the combination of all of the organisms well suited to their environment in one biome, there is an ecosystem that is specifically designed to survive there. If you were to take a kangaroo and place it in the arctic, the kangaroo would not be able to find the resources it needs to survive. The food that it lives off of, the habitat it is used to and the mates it needs to reproduce are not there. That is why each biome is made up of biotic and abiotic factors that specially suit the surrounding ecosystem.

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by Alex

Do sharks really attack humans on purpose or is it because of other reasons. There are different opinions on the subject, but what do you think? Answer that question before you read the rest of this post. Shark attacks do happen and people need to be aware of it, but not as humans make it out to be. Bees, wasps, and snakes are responsible for far more deaths each year than sharks (source).

There are three major kinds of unprovoked shark attacks. The most common are “hit and run” attacks. These occur in zones where there are many swimmers. The shark mistakes the human for something else and usually only bites once and then realizes it was wrong and does not return. Splashing, colored swimsuits, jewelry, and soles of the feet mixed with break surf and strong currents make it hard for the shark to realize what they are attacking. A shark must make quick decisions and quick movements to capture food. Most of the time the shark just mistakes the human for its normal prey. These attacks are seldom life threatening.

The next kind of attack is a “bump and bite” and “sneak” attacks. These are less common, and result in greater injuries and most deaths. This occurs in deeper waters usually and the shark circles the human to see what it is and bumps the victim before the attack. Repeated attacks are not uncommon, but this is a rare attack case. This is usually the result of feeding or antagonistic behaviors instead of mistaken identities (source).

Even though this is unlikely to occur here is a list of some safety precautions to take when going to the beach. Always stay in groups because sharks attack individuals more often, avoid being in the water during darkness, do not enter the water if bleeding, do not weary shiny jewelry because the reflected light looks like scales of a fish, and avoid constant splashing. There are just some of the safety precautions when in the water (source).

After seeing that video in class where they put the man into the clear tank and waited to see if a shark attacked and it didn’t that changed my view of sharks. Did that change your view on sharks and the commonness of them attacking humans? Why and when do you think sharks got this image of being human eating animals?

Check out this cool clip of sharks and human interactions. There are over 400 different types of sharks and most of them are not vicious.  The video (#4 located on the sidebar) shows the interaction between humans and sharks.

by Stevie (AP Biology) 

Ha! I Don’t Need You!… Or Do I?

How does life exist on our planet without everything else? Is it possible for any living thing to survive without using the energy from or bi-products of another organism? This raises an even more extreme question- can any organism survive completely by itself, without any other matter at all? Of course not! Any and every living organism on this planet needs not only extra matter, but also other organisms to survive! This dependence that every living thing has on other organisms and other a-biotic factors in their habitats, or even the biosphere, is referred to as the “Interdependency of Nature.” The interdependency of nature exists on all different levels life in the biosphere! Let’s take a closer look at this concept in the following examples:

Molecular 

On a molecular level, every living thing depends on several key elements to survive. Some of these include oxygen, hydrogen, carbon, and nitrogen. All four elements make up numerous molecules and compounds that make up an organisms body or complex! (Of course there are others, but these are the main four). One simple, yet vitally essential, of these molecules is water.

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All organisms, no matter what species, have to meet a required amount of this substance of they will become desiccated, or dried up, and die. However, organisms must re-circulate water right? If there was only so much water on earth, all of it would have been used up a long time ago and we would never have even existed! All organisms, in many ways depend on water for survival. Many organisms actually break up the elements on water (hydrogen and oxygen) to use for their own ends, mostly in basic cell functions. But if so, won’t they just need more water to replace what they’ve already broken down to use? No! All organisms recycle water! In some way, all organisms resynthesize the hydrogen and oxygen molecules and return the water to nature to be used by other organisms! So we see here that even at the smallest level of existence all parts of nature depend on one another, living and Abiotic!

Cellular

When dealing with individual cells, there are millions upon billions of ways that all things in nature are interdependent upon one another. Take, for example, a nerve cell and the action potential of a nerve cell needed to send a message to another part of the body.What occurs in a nerve to send a message is really quite fascinating! First, a stimulus is picked up on by the dendrites of the cell. The stimulus causes a truly amazing reaction to occur in the cell! First, sodium ions rush into the cell through protein channels on the axon membrane, creating a positive charge inside the cell and a negative charge outside the cell called depolarization. Then, potassium ions rush out of the cell through protein channels on the axon membrane, thus creating a positive charge outside the cell again and a negative charge inside the cell (as it was at its resting potential). This process is called an action potential! The action potential then codes for the synaptic terminals at the end of the axon to expel molecules called neurotransmitters that continue the message throughout the body. This example serves to show that without the sodium and potassium ions, the nerve cell could not function to carry the message on to other parts of the body and the brain would never receive those signals! Thus, it shows us that without the sodium and potassium ions the nervous system could not properly function and meaning that we are dependent on sodium and potassium to survive! In turn, someday our bodies will decease and we can give back that when our bodies decompose, or even through the simple act of sweating!

Another example of the way cells are dependent on matter in nature is in the process of cellular respiration. Cellular respiration is the process by which cells break down glucose and oxygen into ATP (the cells main source of energy), water, and carbon dioxide using the mitochondrion organelles in the cell.

This proves that, like all consumers in the biosphere, we need outside sources to get our energy. Here we use the glucose that we get from consuming food by turning it into a compound called pyruvate and progressing through the three stages of cell respiration to come up with the end result of ATP. Our cells use the energy stored in ATP to perform almost all the cellular functions we need to have carried out in our bodies for them to function correctly. Once again, we depend on other things in nature obtain that energy we need to carry out the essential processes of life and survive! In turn, other organisms in nature, like decomposers, depend on all organisms to give back when they die and use the dead organisms as food for them to create ATP and carry out their own cell functions!

Organismal 

In the bodies of all colemate animals there are organs and organ systems in which those organs function. Not only do the organs within the organ systems depend on one another, but the organ systems themselves depend on one another! Take, for example, the circulation and respiratory systems in humans.

In a healthy human cardio-respiratory system, blood carries oxygen from the lungs to the rest of the body and excretes carbon dioxide from the rest of the body through the lungs. In basic terms, what occurs is the heart pumps blood into blood vessels in the lungs for gas exchange to occur. As you breathe in, you take a lot of oxygen into your lungs. As blood flows through, carbon dioxide on red blood cells is diffused through the membranes of the alveoli (shown above) and oxygen is diffused back across to attach to empty red blood cells and be carried to the rest of the body. Here, the heart is depending on the lungs to get rid of the carbon dioxide and replace it with oxygen and the lungs are inversely depending on the heart to displace and transport the oxygen that they have taken in and supply carbon dioxide for them to expel from the body! Both systems depend on one another to carry out their specific functions.

Population 

In a population members of the same species must depend on one another to reproduce to continue the population of their species. Take giraffes for example.

Each giraffe is an individual in a population that needs to look out for itself and even compete with other members of the same population to survive on the available resources (that is, if the resources should become scarce.) However, one of the two main purposes of life in biological terms is to survive and reproduce! Now, many organisms can reproduce through asexual methods without need of a mate or even another member of the population. But for those who cannot, they must have a member of the opposite sex in the population to mate with and produce fertile offspring and continue the survival of their own species. Hence these giraffes depend upon one another to mate and produce an offspring that will, in good faith, someday survive to reach maturity and find a mate of its own and do the same!

Community 

In a community several different species share the same general environment and must therefore compete with one another for resources. One resource that a species needs is in almost constant need of is food! And though Mother Nature is sometimes cruel, many species do indeed consume members of other species for food and, there-in, energy. Take for example the Great White Shark and the sea-lion.

Great White sharks live in virtually all oceans of the world, and spend a liberal amount of time near islands where their prey, sea lions, lives. The sharks of course consume the sea lions and depend upon them for the rich energy they provide. However, believe it or not, but the sea lions (as a population) benefit from this relationship as well. An ecosystem can only support so many members of a population until the population has reached its carrying capacity. Once this is reached, the ecosystem no longer has the resources to support the numbers of the members of the population, and therefore those not best fit to survive will die off and let those that are live on and reproduce to pass those best-fit traits on to their offspring. Well, in many cases, the sharks will have the same effect! The sharks will wait and pick a target that seems slower, weaker, or most vulnerable to take as prey. So they are also picking out those best fit to survive in the population and encouraging the shift towards higher percentages of those genes in the population from generation. Here we do see that the sharks depend on sea lions for food and energy, but the sea lions as a population depend on the sharks to enforce natural selection and encourage the evolution of the species!

Biosphere 

In the same way that different populations are dependent on one another in a community, so are all communities and the ecosystems they reside in. In the biosphere, all living things exist and carry out the functions that they need to survive. In any ecosystem and even the whole biosphere, plants and algae perform photosynthesis and all the leftover oxygen that they do not use for respiration is put back into the air or water. Well, who else uses that oxygen but consumers? They breathe (or filter) oxygen out of the air or water to use in respiration. The consumers, in turn, produce carbon dioxide as a bi-product of respiration that the plants can use to make their own food in photosynthesis! Here we see again dependency once more! But how does this apply to the biosphere? The neat about oxygen is that it is, in most forms, a gas and can therefore move very quickly and over great distances before it is ever used! An algae in the Gulf of Mexico could be supplying oxygen to a kangaroo in Australia, and a penguin in Antarctica could be providing carbon dioxide for a tree Central Park! Clearly we can see here that all aspects and parts of nature really do depend on one another, whether living or not!

Is there anything in nature that doesn’t depend on some other aspect of nature?  Should abiotic factors be observed as part of nature? Why or why not?  What other examples can you think of?

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by Grant W

Now, you may know that the earth we live on today is highly polluted. One of the worst forms of pollution that we inflict, whether purposely or because of some accident, is an oil spill. Oil spills can be very dangerous to the populations of the specific ecosystem where the oil was spilled. Luckily, oil spills are able to be cleaned which saves the lives of many animals. However, it is incredibly hard to monitor the health of the ecosystem affected by the oil spill after the clean up has been made. Scientists may have found a way to monitor these ecosystems.

Blood tests that were conducted by many scientists at different universities and other institutions have shown that the pollutants left over from the oil spill, long after the clean up, can be extracted from the blood of yellow-legged seagulls. This study, Monitoring PAH pollution in the marine environment after the Prestige oil-spill by means of seabird blood analysis, has helped to show some of the long term affects that the pollutants from oil spills have on the different animals living in the affected ecosystem after it had been cleaned.

“This study highlights the delayed effects of oil spills that we know very little about,” said Stuart Bearhop, a conservation biologist at the University of Exeter in England who was not involved in the study. “It’s very easy to see what happens right after an oil spill: everything dies. But there are probably a lot of later effects we’ve overlooked.”

The seagulls that eat some of the oil from the spills form chemicals in their bodies that are known as polycyclic aromatic hydrocarbons(PAHs), which are compounds that have been connected with cancer in humans. The PAH levels are tested by capturing live birds, taking a small blood sample from them, and then releasing them into the wild. The tests showed that birds that lived near the Prestige oil spill had twice as much PAH as birds that are unaffected by oil spills.

Below are two graphs that show the levels of PAH in yellow-legged gulls from colonies exposed to oil and some not exposed to oil (graph A) and from gulls that were fed vegetable oil and Prestige oil (graph B). In the groups not exposed to oil (unshaded) it is evident that PAH levels are much lower than when the gull is exposed to oil (shaded). In the supplemented oil study, gulls exposed to oil had PAH levels around 85 total PAHs while gulls unexposed to the oil had around 60-65 PAHs.

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The tests used in this study were only being done to animals that were already dead or they were done by taking a blood sample from a living gull, which does not hurt it. This study could possibly be a huge step forward in learning some of the long-term effects of oil spills so that animals that are in areas where these spills happened can be better watched over and taken care of (Source).

Snail Shell, Photo source

by Anna

In biology class, structure determines function is repeated over and over to stress its importance to the balance of life. The inner ear is no exception. The Cochlea is a fluid filled spiral shaped tube in the inner ear vital to hearing. The cochlea turns sound waves into nerve impulses so they can be read by the brain. It acts as a mini translator for the brain.

According to a recent study, examining the structure of the cochlea could help scientist’s further study the hearing of extinct mammals and the damaged hearing of current non-testable animals due to their inability to stay still. The more plate-like cochlea limit the span of octaves, the tone on the eighth degree from any given tone, that the animal can hear. If the cochlea is tightly coiled, the animal usually has more ranges of hearing.

The cochlea’s walls get smaller as it curls inward, so as the walls get smaller the waves get stronger because they are in a smaller area. If the cochlea is not tightly curled, the animal’s hearing is not as ranging because the waves do not get any stronger within the inner ear.

Mammals usually have tightly curled cochleas and birds and reptiles usually have plate-like cochleas. Animals with tightly curled cochleas may need to hear better in order to survive in their habitat. Maybe they have prey that makes strange and quiet sounds or they need to get away from predators. Animals with plate-like cochleas may not need to have better hearing in order to survive. Maybe they can hear predators and prey easily without having extreme hearing.

What are some animals with cochlea that are tightly curled?  What are some animals with plate like cochlea?  What are some advantages to having a bigger range of hearing?

H. Fearnbach, NMML, NMFS permit 782-1719, Picture Source

by Katie

“Cool! An albino whale!” was the first thing I thought when I saw this picture. Who wouldn’t stop to look after seeing the picture? However, it turns out this whale isn’t albino. “It still has signs of darker pigmented areas on its body” (Source). Another clue would have been if the individual’s eye is pink, but no one actually got to see the eye. It’s possible that this whale has Chediak-Higashi Syndrome.

Chediak-Higashi Syndrome is an inherited immune and nervous disease. It is an autosomal recessive disease that is VERY rare. In humans, there have been only 200 cases recorded. Besides humans and killer whales, it (or something very similar) has been observed in mice, Hereford cattle, blue smoke Persian cats, and mink. (Source)

“Other symptoms associated with the disease include enlargement of the liver and spleen,…and depressed activity of other cells, called natural killer cells, that are involved in defending the body against infection” (Source). The coloration isn’t the main problem; although, if the whale was being hunted, it could be.

One thing that really caught my attention was that although this individual is obviously different from the others and may be carrying diseases that are harmful to the pod (a “pack” of orcas), the individual is still submerged in the pod. Humans tend to shun those that are different or sickly. Maybe we should learn something from these whales.

For more information on this whale, go to this site or this site. For more information on Chediak-Higashi Syndrome, go to this site or this site.

What other ways could Chediak-Higashi Syndrome affect the individual? What are some other causes for albinism, or partial albinism? Hypothesize why the pod has accepted the individual, while other species would have not.

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by Connor

Who do you think would win this death match? If you guessed shark, you’re wrong. An octopus in the Seattle aquarium was put in a bigger tank full of sharks and other big fish. The marine biologists thought that the octopus would be fine with its camouflage, and if the sharks attacked, then the octopus could handle it. But, a little while after they put the octopus in the tank, dead bodies of sharks kept appearing in the tank. The biologists were puzzled, and decided to investigate, but what they found amazed them. They caught this footage of the octopus attacking the shark! After seeing that video, I’m not as scared of sharks anymore. But octopi are another story entirely.

The Octopus is really an amazing animal. According to one source they are strong enough to rip the tail off a shark (that is what was wrong with all the dead sharks- their tails were ripped off and their insides were gone)! Also, they are able to open jars and solve mazes and puzzles (and they taste good to boot!). If you want to know more then read here.

According to one article, the octopus has the most complicated brain of all the invertebrates. The octopus brain is estimated to have 300,000,000 neurons. These neurons are arranged in lobes and tracts that are more specialized than simple ganglia. An octopus has a “good” memory and can also learn (source). On the other hand, the shark’s nervous systems consist of a simple brain, spinal column and a network of nerves (source). Before researching this, I had no idea that octopi were this complex, but now I know the truth. It’s pretty amazing that these creatures are that smart, but you learn something new everyday. It makes me wonder what other animals are that smart. Only time will tell.

Do you think there are other animals out there with this level of intelligence?  Do you think it is possible for an animal’s intelligence to evolve to a point where it can learn and understand our language?  Would that be a good thing? Bad thing?

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by Emily R

Cancer is a serious disease that affects millions of people around the world. It ha