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 Equilibrium in Natural Systems

When pressures and temperatures become unbalanced in Earth’s atmosphere, it can produce some dramatic effects as the system tries to rebalance itself or re-equilibrate (reach equilibrium). Many of these changes are things that are witnessed every day on a small scale in the form of weather, such as wind, rain, snow, fog, etc.

Sometimes, however, Earth’s atmosphere experiences very large imbalances which can cause massive and very disruptive change. The extreme weather events of the past decade are good examples of extreme changes that required re-balancing (equilibration). Not only did they have environmental impacts, but also disastrous consequences for the hundreds and thousands of people in their wake.

Review the  Discussion resources .

Then, during the week, discuss with your classmates:

1. What kinds of natural imbalances might affect your region? What makes your region particularly vulnerable to these imbalances?

2. Provide a specific example of a weather incident/natural disaster that occurred in your area in the past and discuss how the incident was handled by local residents and town/state officials.

3. What can people in your area do to prepare for a similar incident? Consider what can be done prior to, during, and after the disaster (be sure to include specific details using information from the CDC and/or FEMA).

4. Compare your area to that of a classmate. What environmental features do you have in common to produce similar natural disasters OR what features vary, leading to completely different disasters? Would rescue efforts differ as well?

5. What predictions are being made for how climate change will impact either the frequency or intensity of future natural disasters in your area? (Hint: refer to the extreme weather and hurricane resources provided above to find information to support your ideas).

 Endangered Species

Although humans; like all other living creatures, have had to make changes, adjustments, and adapt to survive and thrive, it is humankind that has also had a profound impact on the lives of other creatures on Earth. Sometimes this has been a beneficial impact, but in many cases, it has been a disaster for other creatures.

Review the  Discussion resources

Endangered Species

Using the Internet, your textbook or the Library, conduct some research on your own on an endangered species (plant or animal) of your choice. Consider the biological, ethical, and economic aspects that have led not only to its endangerment, but also the role humans have taken in protecting the species. Then, during the week, be sure to address the following:

· In a short paragraph (5–7 sentences) describe the species that you chose to learn more about and the basic reasons for its endangerment.

· What characteristics make some species more vulnerable to extinction, while others seem to thrive despite changes in their surroundings?

· How do the extinctions of other creatures affect humans directly and indirectly?

· Why are decisions about recovery and preservation of these creatures so complicated?

· What, if any, ethical responsibilities do humans have to other creatures on the planet?

· What sorts of trade-offs would you be willing to make in order to help protect an endangered species? Would you make the same trade-offs for all types of species (plants, insects, amphibians, etc.) in addition to those more popular species many people tend to be fonder of, like whales, tigers, and pandas?

· Later in the week, compare your chosen organism to some described by your classmates. Do they share any common features? For example, are they endangered for the same reasons? Do they share similar habitats or behaviors?

 Genetic Inheritance and Mutation

Mutations are changes that occur within the genes of an organism. Sometimes these mutations impact a single gene, while other mutations impact the number or structure of entire chromosomes. Since many mutations change just one tiny piece of information in one single piece of DNA, they usually do not cause any problems. For example, imagine if someone sent you a long email and accidentally misspelled the word "friend" as "freind." You would still understand the email and would probably still even catch the original meaning - this is a good analogy for what happens with a point mutation, where just one part of a gene is changed.

However, sometimes a single mistake can make a big difference. Imagine if, while composing a long email, you accidentally select and delete an entire paragraph or perhaps auto-correct changes a critical word. You can imagine (and perhaps have even experienced) how such a mistake might cause great confusion and miscommunication.

Many genetic disorders are caused by changes to a single gene in the form of a point mutation or due to a chromosomal abnormality like a chromosome disorder. Sometimes these mutations are passed from one generation to the next, just like other harmless traits like eye color and blood type. These mutations may cause specific disorders, or they may predispose a person to a common disease like cancer or heart disease.

Review the  Discussion resources  to learn more about genetics and the implications of our genetic knowledge:

During the week, discuss the following with your classmates. Be sure to use the provided course materials and feel free to share additional information you find in the PG Library or through your own research.

Imagine that you have a particular genetic trait and that you have four children. Two of the four children also possess this trait. Meanwhile, the other biological parent of your children does not possess the trait.

· Explain why you think the trait in the scenario is dominant or recessive.

· Based upon your response, describe why it would or would not be possible for the trait in the scenario to “skip” a generation.

· Patterns of inheritance within organisms like pea plants, fruit flies, mice, and others are somewhat easy to determine since their mating practices can easily be controlled. Apart from controlling who mates with whom, what other characteristics make species like these ideal for studying genetics?

· Select and describe a health problem that you believe has a genetic component at least partially inherited. If you do not identify an inherited health condition within your family, choose a disease that interests you or impacts a friend or other family member.

· Would you be interested in having genetic testing to determine whether you carry a genetic mutation for a particular disorder or a genetic predisposition for a disease? Why/why not? What are the advantages and disadvantages of determining your predisposition?

· Explore the current state of research for the health problem you selected. Focus on one of the following to discuss as they relate to the genetics of the disease:

· Cause

· Testing/Screening/Prevention

· Treatments/Therapies/Cures

· Throughout the week, discuss similarities and differences between the diseases you and your classmates describe.