A Spring Without the Songs of Birds

Rachel Louise Carson was born May 20, 1907 in Springdale, Pennsylvania. Throughout her life, she became known as a writer, biologist, and ecologist. After earning her Master's degree in zoology from Johns Hopkins University in 1932, she wrote pamphlets on conservation and natural resources and edited scientific articles, but her real passion was in writing about nature and the living word. After working for the U.S. Bureau of Fisheries for 15 years, she quit to pursue her writing career. She wrote books designed to teach people about the wonder and beauty of the living world, but later disturbed by the overuse of synthetic pesticides in WWII, she changed her focus to warning the public about long-term effects of this misuse. She published Silent Spring in 1962 alerting readers to the horrible potential effects of using DDT before dying after a long fight with breast cancer in 1964. Her legacy in her books continues to inspire us about the world and all its beautiful creatures.

Silent Spring opened new doors in environmental thinking. The negative effects of synthetic chemical pesticide overuse was not a commonly discussed topic in the scientific community. Even though Rachel Carson was criticized as an alarmist for presenting such an extreme outcome, her ideas aren't really that out there since she just took individual problems from many places and put them together in a worst case scenario. People thought that if chemistry can make it and it makes their lives easier, all is good! What Carson described is that even if chemistry can invent a solution, it's not always the best option. Production of DDT killed insects and did not have immediate health effects, but look at what happened 20 years down the road!

Carson spreads negativism about the use of DDT and other harmful pesticides, but what does that mean for other countries who need it just to stay alive? Africa has an abhorrent problem with malaria. If Carson convinces enough people and these pesticides get banned, does that make her (posthumously) a genocidal maniac? Her ideas would technically be the cause of the deaths of almost 2 million Africans that could have been saved by pesticide use (it would just kill them later...).
 

What is Life??

When posed with a difficult question, I do as pretty much every other kid with internet access does: I google it. Since we're also talking about life with respect to viruses and prions, I stuck that in the Google bar as well.

So here's what I found. Viruses are non-cellular infectious particles that consist of DNA or RNA wrapped in a protein shell. Since viruses cannot grow or replicate on their own, they are considered to be "obligate intracellular parasites" and thus, not alive, even though they possess characteristics of both living and non-living things.

Prions, a term coined by Stanley Prusiner to describe a "proteinaceous infectious particle," is like a virus, but it's just the protein shell without the inner DNA/RNA. Essentially, prions can affect animals by attaching their protein parts to replicating cells and taking advantage of them by using their parts to make copies of themselves. Prions have been related in research and characteristics to diseases such as Scrapie in sheep, Bovine Spongiform Encephalopathy (Mad Cow Disease), Kuru (which existed in a tribe of Fore Highlanders in Papua New Guinea because of ritual cannibalism), Creutzfeld-Jacob Disease in humans, and vCJD (a variant of Creutzfeld-Jacob Disease that seems to have come from eating BSE infected cattle in Britain).

But are they considered life?

If we define life by the ability to replicate on one's own, then no. But if some characteristics of living organisms qualify them to be considered "alive," then they are. More important than defining viruses and prions as alive or dead though, is doing research in these fields to determine what impact these organisms have on daily life and what threat they could potentially cause in the future.

3 Diets for 3 Blood Types

Three blood types exist in humans: A, B and O. O is the absence of the antigens that make up A or B blood (or AB blood that contains both types). A blood type diet is a nutrition plan based around one's blood type. Peter D'Adamo advocates this diet and asserts that it can assist with allergy and infection resistance in addition to weight loss and overall good health.

People with Type O blood should stay low-carbohydrate, high in protein and low in dairy products. Also, avocados, brazil nuts and oranges should be avoided. Type O people should engage in lots of exercise.

People with type A blood should avoid red meat and keep a low dairy intake while eating plenty of fish and vegetables. These people should only lightly exercise.

Blood type B people should avoid chicken and bacon while eating plenty of meat and dairy. Some fish and plenty of fruit and vegetables are also recommended.

People with blood type AB should follow guidelines for blood types A and B.

Aside from dietary suggestions, the blood type diet places people in other categories. Type O is the hunter, the earliest human blood group. Type A is called the cultivator which dates back to the beginning of an agricultural society. Type B is the nomad and is characterized by a strong immune system and a flexible digestive system. Type AB is the most recently evolved type and these people are called the enigma.
         

Mitochondrial Eve

This woman, Mitochondrial Eve, is the oldest maternal ancestor of all living humans. Mitochondrial DNA is passed from mother to children and is an exact copy of only the mother's code. Since the fathers never factor in to this genetic aspect, the mitochondrial DNA is purely maternal. For this reason, we can trace our roots back exactly on the mother's side.
 
Mitochondrial Eve is estimated to have lived around 200,000 years ago in East Africa (Mesopotamia). Even with this connection that links all people, because people migrated all over the world so long ago, diversity shows this. There's a difference between how people look. For example, Native Africans have a darker skin tone from pigmentation than Scandinavian dwellers like Swedes. While they are both descendent from the same Mitochondrial Eve, this variation shows how populations can evolve over time to have the best genetic advantage for the region in which they live. Here is an artist's rendering of Mitochondrial Eve:
 
And this shows how people migrated after her origins:

Extremophiles!!

Not every life on this planet lives the same way. Certain species thrive in alternative environments. These species are called extremophiles. A few examples follow:

Halophiles: organisms that require at least 0.2 M concentration of salt (NaCl) for growth

Acidophiles: organisms that grow optimally at a pH of 3 or below



Xerophile: an organism that can grow in extremely dry, dessicating conditions

 

Normally, organisms cannot live much less thrive in these arid, acidic or salty environments, but these special extremophiles show that life can survive in these extreme conditions. Because these particular organisms have evolved to survive extremes, almost anything is possible with life!

Inductive vs. Deductive Reasoning

Inductive and deductive reasoning are both forms of logic used to establish hypotheses, but the methods are different. Deductive reasoning uses generalizations to make a specific conclusion. Inductive reasoning takes specific events and draws a generalization from those.

Deductive reasoning is shown in processes like the scientific method. You can phrase a hypothesis in an "If, then" statement, describe the result following "but" and draw a conclusion with a "therefore." If we mix two chemicals and a precipitate forms, then the chemicals are at least partly soluble in one another, but no precipitate formed when we mixed the chemicals, therefore the chemicals are not soluble in one another.

Inductive reasoning is the opposite of deductive reasoning. You take a bunch of different situations and examine the commonality of them in order to generalize a main rule for them all. Draw 4 different triangles. If you examine them all, you find that the angles of each triangle add up to 180 degress. From these separate instances, we draw one conclusive generalization that for any triangle, the angles will add up to 180 degrees.

How Awesome This Class Is

Paper footballs and Jacob's ladder during class? And yes, there's things to learn from both. But it's not all fun and games. Simple things like sex, salad bars and antelope turn into discussions about such deep topics as bioterrorism! Things that might otherwise be put into a boring lecture are made interesting and engaging at 11 am. The things I'd heard about other Scientific Inquiry classes made me less than enthusiastic about taking this required course, but Dr. Rood finds a way to hook us in for the lesson. I don't even check my watch until he says class is over! It's a class I'm actually excited to get to because science is always interesting and fun!