Share
Explore BrainMass

Speciation and Extinction

Speciation and extinction have shaped the biodiversity we observe on Earth today. Organism and populations are constantly evolving and changing in response to their environment.

1) Discuss small populations and extinction vortices.

2) Discuss reasons why plant and animal populations may differ in their susceptibility to extinction

3) discuss three reasons that exotic species are often able to drive native species to extinction.

Solution Preview

Question:
Speciation and Extinction
Speciation and extinction have shaped the biodiversity we observe on Earth today. Organism and populations are constantly evolving and changing in response to their environment.

1) Discuss small populations and extinction vortices.

2) Discuss reasons why plant and animal populations may differ in their susceptibility to extinction

3) discuss three reasons that exotic species are often able to drive native species to extinction.
Response:
1) In order to address this question you need you first understand extinction vortices and then apply them to small populations to come up with a series of reasons why small populations are often more susceptible then larger populations to extinction.
Extinction Vortices: You likely have a definition in your notes or classroom text, but essentially vortices are just models that scientists use to categorize extinctions based on their likely causes. There are four different vortices:
R Vortex - describes an environmental disturbance event which decreases the population size and skews the population dynamic, for example a disturbance which skews the sex ratio.
D Vortex - describes an environmental ...

Solution Summary

In this solution I discuss these topics:

1) Discuss small populations and extinction vortices. Answer summary: In order to address this question you need you first understand extinction vortices and then apply them to small populations to come up with a series of reasons why small populations are often more susceptible then larger populations to extinction.

2) Discuss reasons why plant and animal populations may differ in their susceptibility to extinction Answer summary: To answer this question you need to first brainstorm a list of probable causes for extinction, then consider how a plant vs an animal population could respond. Some causes (this is just a quick brainstorm of mine; please don't consider this list complete and I encourage you to come up with some other causes):

3) discuss three reasons that exotic species are often able to drive native species to extinction. Answer summary: To answer this question you need to think not only of the exotic/introduced species and the species that it may drive to extinction, but additionally the entire food web and community complex. Introduced species: When an introduced species arrives in a new environment, it's a bit like starting with a clean slate, it gets to leave a whole bunch of baggage behind, for example diseases, parasites, predators, and competitors.

$2.19