Zeke Moisey
Mrs. DeMarco
Honors Environmental Science
27 November 2012
Chapter 4 Test Questions

1.(5pts) Why are large animals that we tend to value (bison, whales, etc.) more likely to go extinct than smaller ones that are nuisances (mosquito’s, mice)?

Larger mammals, on the other hand, must endure the hard times when there’s little food or extreme weather. Their large size constrains them from digging burrows or lowering their metabolic rates for extended time periods. In a sense, larger mammals face the elements head-on like a fearless adventurer who might not make it through alive, and is forever changed by the experience. On an individual level, large mammals tend to live significantly longer than smaller ones. For example, elephants can live up to 70 years, while shrews are lucky to reach two. Because of their faster generation times, small mammals should evolve faster, and small mammal species and genera should appear and go extinct faster – but this is not the case. But overall, small mammals’ ability to hibernate or enter a state of torpor seems to give them the largest benefit for prolonging their species duration. And the small mammals that didn’t hibernate had relatively faster evolution rates, as they were forced to cope with the elements. The longest living genera in the study were a mole, two gliding squirrels, and two dormice, which lasted about 16 million years, and all had the ability to burrow or hibernate. The tapir was the only large mammal that evolved at a slow rate more akin to the smaller mammals. Most large mammals that didn’t hibernate evolved into a new species or went extinct in just a few million years.

2.(5pts) Draw J and S shaped curves of population growth. Label both axes. Describe situations in nature in which you would expect to see each of these curves. YOU NEED TO JUST DRAW A J CURVE AND S CURVE ONCE YOU PRINT IT OUT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Do not forget!!! Valuable Points. haha

The J-curve represents population growth under optimal conditions, with no restraints. The S-curve shows a population equilibrium. Notice how the J-curve spikes well above and then crashes below the carrying capacity whereas the S-curve rises up to the carrying capacity and then oscillates between slightly above and slightly below it. The J-curve is when the biotic potential grows exponentially and then when the species exhausts all resources it will die off. On the other hand the S-curve is when the species functions in a climax community where all inhabitants work in unity and equilibrium.

3.(5pts) Describe some (5) selective pressures on other species that result from the human species. Pollution
Pollution severely affects the health and well being of both animals and humans. These causes the animals to not only fight for their life but at the same time try to adapt to this pressure and avoid extinction. This could cause birds to change their flight courses.
Deforestation
Due to industrialization, the world's forests are beginning to disappear. Not only are they homes to a great deal of plant and animal life, but the roots of the plants hold the soil together and prevent soil erosion, which is an important part of the water cycle. With the destruction of forests it is causing animal species to adapt and change their habitats to cope with the deforestation.
Global Warming
The release of gases such as carbon dioxide and methane into the environment, particularly from vehicles and industries, contributes to global warming by causing the average temperature around the world to rise. Then when the temperatures rise this then causes animals such as polar bears to adapt to warmer weather and then possibly they will have to relocate or go extinct.
Acid Rains
Which are caused by sulfur dioxide emitted by factories mixed with haze. And the acid rain water, if got mixed up with the rivers' or lakes' water will kill the aquatic and marine life like fishes. And if the fish do not want to die off or go extinct they are forced to adapt to the acid rain and figure out a new way to cope with this factor.
Industrialization
This is the building of roads and buildings, and when this is done most of the time we are taking away land from animals and destroying their habitats. And when this occurs they are forced to adapt to the city life or relocate into an area where either way they will have to adapt and cope with the new factors.

4.(5pts) Describe some (5) indications that the human population is facing environmental resistance.

Human population is subject to environmental resistance. Human society has overcome some natural resistance, such as availability of food, by things like farming and such. Eventually, there will always be environmental resistance, like new diseases that ravage the population due to overpopulation, or global warming, or many other things. We can push how much resistance there is at each point, but there is always going to be resistance, just at different points or in different ways. Antibiotics, disinfectants and bacteria resistant to them have been detected in environmental compartments such as wastewater, surface water, ground water, sediments and soils. Antibiotics are released into the environment after their use in medicine, veterinary medicine and their employment as growth promoters in animal husbandry, fish farming and other fields. There is increasing concern about the growing resistance of pathogenic bacteria in the environment, and their eco-toxic effects. Increasingly, antibiotic resistance is seen as an ecological problem. This includes both the ecology of resistance genes and that of the resistant bacteria themselves. Little is known about the effects of sub inhibitory concentrations of antibiotics and disinfectants on environmental bacteria, especially with respect to resistance. According to the present state of our knowledge, the impact on the frequency of resistance transfer by anti-bacterial present in the environment is questionable. The input of resistant bacteria into the environment seems to be an important source of resistance in the environment. The possible impact of resistant bacteria on the environment is not yet known.