Monday, November 3, 2014

Unit 4 Blog

Unit Vocabulary:


Species Richness - the number of different species







Species Evenness - comparison of the number of individuals in each species; how the magnitude of different species relate to each other





Microevolution - minor genetic changes within a population over time





Macroevolution - gives rise to a new species, phyla, genus, etc.







Evolution by Natural Selection - environment chooses which animals are most likely to survive and reproduce resulting in a change in genetic composition of the population over time





Evolution by Artificial Selection - humans select which individuals breed, normally with a preconceived set of desirable traits, resulting in a change in genetic composition over time





Allopatric Speciation - because there is a physical/geographic separation of the population





Sympatric Speciation - caused by something other than geographic separation of the population





Genetically Modified Organisms - produced by copying genes with a desirable trait and then inserting them





Fundamental Niche - ideal environmental conditions for a species







Exponential Growth Model - grow exponentially (greater than linear) resulting in a J-curve





Logistic Growth Model - grows quickly but plateaus at a constant rate (S-curve)



Carrying Capacity - maximum number of individuals that can be supported indefinitely in an environment





Keystone Species - has a disproportionately large effect on an ecosystem


Current Event- Instead of finding a current event for this unit, I'm sending you to a website. Go to Biodiversity HotSpots and review pages 144-147 in your textbook. Pick a hotspot on the website to discuss (when you click on one of the regions, a list of specific areas will come up, pick one of those.) Discuss the following points specific to your chosen hotspot. Be prepared to discuss this portion of your blog in class.

What is a biodiversity hotspot and why are they important? A biodiversity hotspot is a threatened area that has high levels of biodiversity; they are important because of their high levels of biodiversity which are key to the intrinsic and instrumental value of the ecosystem, most directly provisions and maintaining the ecosystem itself.
Where is your hotspot located and what type of ecosystem is present there (posting a map showing where your hotspot is located could help you here). My hotspot is located in the Philippines and contains many types of forest ranging from rainforest to seasonal forest as well as some savanna.

Describe at least one endemic plant species and animal species found here. Explain what it means to be an endemic species.

This is the blossom of the sacred garlic pear plant (Crateva religiosa) endemic to the Philippines.





This is the Philippine tarsier (Tarsius syrichta), a primate endemic specific islands in the Philippines.

An endemic species is one that is unique to a defined location.

Describe the human induced and/or natural reasons why biodiversity is decreasing in the area. The growing population of the Philippines coupled with lax resource conservation laws that are constitutive of a developing nation due to economic dependence on natural resources are the main reasons this hotspot is so endangered. Specifically, mining and land conversion have ravaged the natural ecosystems. Invasive species have also taken their toll.

Explain what is being done to protect the area. There are national parks and protected areas which are being pushed to be expanded every year. There is also work being done to ensure that the boundaries are clearly demarcated and enforced since that is not really happening right now.



Pick a Side- In a paragraph, using AT LEAST 5 of your vocabulary words (they don't have to be the ones listed above, just any words from chapter 5 or 6 in your book) describe the ideal conditions in which a species will either adapt to changes in it's ecosystem and evolve OR conditions that would lead to species extinction.

Ideally for a species to adapt, there must be a high level of genetic variation (many different genotypes) to ensure that there are many different phenotypes. Having different phenotypes makes it more likely that there will be at least some individuals that are adapted to whatever change occurs. A small population ensures that the beneficial adaptation can be quickly spread throughout the population to increase the fitness, or the ability to survive and reproduce, of all individuals. A small generation time also helps ensure that the beneficial mutation can be passed on quickly.


Big Picture Reflection- This is where you will make the four BIG PICTURE connections to the ENTIRE UNIT. Please tie in information you learned in your reading, from completing your labs and from your current event. There is not an exact length that I am expecting other than it should definitely be at least a paragraph for each section, should be thorough and show understanding of the topic.


Human Impact: Humans impact community ecology by affecting populations. Pesticides and herbicides may kill off a food source for another creature which would reduce the number of individuals of that species as well. Because the predator numbers have decreased, other the populations of other species they may have fed on would increase since there are no longer as many predators to consume the species. Biomagnification may also occur, where predators eat contaminated prey and are eventually poisoned because they have eaten so much contaminated prey. This happened in the case of DDT and bald eagles. The DDT ranoff into water sources and was taken up by the fish which were in turn eaten by the bald eagles. Humans may also introduce foreign species that crowd out endemic flora and fauna as in the case of zebra mussels and purple loosestrife. Finally, humans can genetically engineer organisms or artificially select for desirable traits and affect populations that way. Examples include genetically modified crops and bacteria as well as dogs respectively.


Environmental Impact: Populations impact their environment by interacting with one another and also with abiotic factors. For example, decomposers help break down dead organic matter into soil which is then used by other organisms as a habitat and for nourishment. A population decrease or increase can greatly affect other populations in the community, and thereby affect the carrying capacity for other species as well. This is especially true of keystone species who are disproportionately important to the ecosystem. Loss of a keystone species can have drastic effects on the community and ecosystem as a whole.


Economic Impact: Human-introduced invasive species are costly to manage and remove. Zebra mussels have been known to clog pipes and other plants can crowd out crops. Herbicides and genetically modified organisms have also become a very lucrative part of the economy. Figuring out how to insert an insulin-producing gene into bacteria or how to make wheat more drought-resistant is extremely marketable. GMOs along with chemical controls have also given rise to the organic food market which is a sizeable part of primary sector activities. Ecosystems have instrumental worth through provisions and regulating services that are economically valuable as well.


Government Legislation: The Environment Protection and Biodiversity Act 1999 is Australia's key piece of legislation that aims to protect habitats and preserve species. Other countries have similar acts. The United States has an entire department, the Environmental Protection Agency dedicated to preserving biodiversity and environments. It sets regulations on the amount of pollution generation, which areas may be developed, how they may be developed, and many other similar rules. The Federal Drug, Food, and Cosmetic Act allowed the EPA to set a maximum amount of pesticide residue that could exist in foods. There have also been many other non governmental organizations that work to preserve biodiversity hotspots and save endangered species like WWF, CEPF, and UNEP.

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