PDS APES 5th Period 2009-10

GO TO BED. I AM. BRAIN RULE #7: SLEEP WELL, THINK WELL.

Ok, here is one of those, “its really late and my brain is dying so this might sound stupid” questions. I was looking over the trophic levels and the way they are labelled. I understand why the producers are trophic level 1, primary consumers are level 2, etc. However, totally forgot the point of the other labelling system, which begins with primary consumers and looks like a 1 followed by a degree mark. If anyone could explain the point of this, that would be fabulous. And thanks to everyone for the help about the soil!

James, thought this might at least give you a laugh, if not some inspiration:

Okay, so I’m studying chapter six right now and I came across the vocab word “biotic potential.”  I have always had a hard time understanding this.  This definition in this book says it is a species capacity for growth.  Is this related to this species carrying capacity??  But it also says in the book, “together biotic potential and environmental resistance determine carrying capacity.”  I don’t really get this in a real life scenario… any help?

and jessica and james- yall should appreciate this post because we could not figure out this before this test and then it was a question!

Hey guys, two quick questions.  On test number 4, question 31 (which was a short paragraph about two fruit-eating pigeons.  They live among the same species of trees, the larger pigeon eats the larger fruits and uses the stronger branches to perch while the smaller species of pigeons eats small fruits from weaker branches)  The question asks what this is an example of.  The correct answer for this question was competitive exclusion which we have defined as- If two species within the same niche coexist in the same ecosystem then one will be excluded from the community due to intense competition (both suffer, losers migrate or die etc.)  I really don’t see how this question fits this definition.  If the pigeons are perfectly happy eating the same fruits at different tree branch levels, what is the big deal?  I don’t see how one of them would have to move or how both suffer. I put mutualism because I thought it seemed as if both benefited?  If someone could help me out or share their ideas that would be great!

Also, feeling kind of stupid, but this math thing is killing me.  Like on the last test, if a problem says their is 1.2 billion people, how does the decimal effect the number of zeros you put on the number?

On the last test I was confused as to whether pre-industrial or post-industrial had lower growth rates. I understand that pre-industrial countries have Zero Population Growth because their birth and death rates are practically the same. But where does that leave post-industrial countries, whose death rates exceed their birth rates?  Does that mean that now post-industrial countries have negative growth rates? I understand the social/economic/scientific reasoning behind the patterns within each individual stage, I just get confused when it comes down to contrasting the Stage 1 and Stage 4 in terms of overall growth, moreover which one experiences less of it.

Ok so on Test 4, number 9…”long-term, large-scale evolutionary changes between groups of species is…” the answer is Macroevolution or Speciation. I guess I am just getting all of these terms confused but could somebody help me easily distinguish between coevolution (which i thought it was), macroevolution, and convergent evolution–These are the ones I mix up and I’m still a little puzzled from the book definitions.

I’m still confused on winds.  I was looking over my chapter 5 test, and question number 4 describes winds that produce arid climatic regions called deserts.  The answer is Hadley cells, but I am confused because I thought the difference between Hadley and Ferrel winds were that Hadley cells governed the tropics and Ferrel cells governed temperate regions.  Maybe I was wrong about that, but I’m pretty sure it’s right…. Maybe I am just not really understanding these winds.  Any help?

Can anyone explain the difference between a stewardship worldview and an environmental world view? They seem too similar to distinguish between the two. Which one would apply where in the environmental history of the United States?