PDS APES 8th Period 2009-10

Natural selection + geographical isolation…on the way to new species when reproductive isolation happens. 3 minute video.

Alright, so #17 on our Chapter 6 study guide asked a question along the lines of “What happens when a population transitions from exponential to logistic growth?” The only thing that I could deduce from the reading was that the population “settles in” by fluctuating sinusodially around K. But the question in the study guide seems to imply there are greater implications. Do yall know of any from the reading or Isle Royale?

Hope studying is going well!

Hey Y’all!  So I was reviewing Chapter 6 and came across a section I don’t remember discussing in class (pg.107).  Our book discusses three different aspects of stability or sustainability (inertia, constancy, and resilience).  I’m just having a little bit of difficulty distinquishing between the three, mainly the difference between inetia and resilience.  From what I understand, inertia is kind of like the “before” — resist being disturbed — and resilience is kind of like the “after” — repairing damages after a disturbance.  Does this sound right?! Thanks, guys!  –Molly =)

We brushed over the topic of indicator species in class, but on the study guide D. Will. sent out, he said to know what they are and some examples. I know that indicator species are organisms that, when they are affected by seomthing in their habitat, will delineate, therefore tipping off to biologists that there’s something wrong in that habitat, but I’m wondering what are some examples of animals that were affected by temperature (global warming) or disease?

While I was reading this article I was a little confused about something. We read the article like the bass and all the other fish that the snakeheads would beat using the competitive exclusion principle. Why cant the bass and other native fish just find their realized niche? Is it even relevant here?

Okay, so this is a pretty famous video taken in Africa. I think it is a really great example of both predation and competition; both the aligators and the lions are preying on the water buffalo, while they both have to compete with each other for the same resources. Now, hopefully, I’ll be able to figure out how to attach the video…

http://www.youtube.com/watch?v=LU8DDYz68kM

Syd: Your link works, but I’m embedding the video. I’ll teach you how next semester. -Mr. W

Now i understand that Generalist species can easily “adapt” to a change in environment an the  food it eats, where specialist species focus more on one specific method of eating or have a specific need of one type of  food. Like a Panda bear is a specialist because it only eats bamboo shoots. But a Snakehead for example, i know as stated in the article that it is quick to “adapt” to a change in environment.  It will eat more than just one type of fish, however, it specializes in preying on fish. It has evolved a large mouth, and rows of sharp teeth to exclusively eat fish. does this make it a Specialist species, because it only preys on fish? or a Generalist species, because it can adapt to more than one environment?

Ok so i pretty much understand this concept, but i’m just wondering what exactly makes a secondary succession? Does this mean that there are still grasses and small plants, or does it wipe out all living organisms, and they must rely on germinating seeds to bring back their species?

I am slightly confused on the differences between Keystone and Engineer Species.  Are they completely different, or is there overlapping?  Can an Engineer species be a Keystone Species, like the elephant?  Or is an engineer species automatically considered a keystone?  If anyone has any distinctions, categorizations, or knowledge that could help me out i would appreciate a comment.  Ill check back later tonight.

I understand the definition of a keystone species, but couldn’t any animal be considered a keystone species?  If you remove a species from an ecosystem then it will affect the population in some way.  You are removing some animals food source which will change they way they feed and maybe the animal that feeds on them.  By taking away some species, you are bound to disrupt the food web.  So what makes a keystone species different from the rest?