[Vivskies]

Yeah, I'm having some difficulty with these questions:

1) What makes succession different from evolution?

2) What does the phrase, "Mother nature always wins" mean? How does it apply to the concept of succession?

3) What are the steps in a secondary succession?

[asianpanthers]

succession (in an ecosystem) is usually described as a directional change in the types of things that inhabit it. typically going from less complex to more complex. like grass and weeds to bushes and shrubs, then different kinds of trees. this usually takes a long long time to occur. this usually goes on until the ecosystem becomes terminal and the cycle will "reset" like a forest will burn, redistribute the nutrients to the depleted soil so this cycle can repeat itself.

evolution is kind of tough to explain because there are two different theories on how it actually occurs. like one theory is that there are many mutations that occur in a set amount over a given amount of time. the other is of course that mutations occur randomly, which is the one that is most accepted. these mutations are selected for by evolutionary pressures like immigration/emigration, predation, competition, bottle neck effects/genetic drift, etc.
-basically, evolution occurs when a new species that can't interbreed and produce a viable offspring with the parent population occurs. (inviable offspring example: donkey mixed with a horse - makes a mule which can't make more mules due to chromosome incompatability)
-the other thing to understand is that evolution takes a LONG LONG time. and by the commonly accepted theory of mutation rates, may not happen at all.
-another thing to understand is that most mutations are deleterious (that occur on functional dna and actually change the amino acid that it will code for) so...that's another set back. i'm sorry if this wasn't a good explanation. there's so much to explain about evolution in order to actually explain it, but this is basically what it is.

the difference here, is the level at which it acts. succession is on an ecosystem while evolution acts on a population.


mother nature always wins? i have no idea? i didn't think this was a win or lose scenario. hahaha but i guess maybe that the ecosystem is gradually becoming more and more complex? and the cycle can repeat itself by itself? by means of succession...? maybe? i dont know.

secondary succession is kind of like invasive behavior in a plant...like one type of foreign tree growing in an existing forest. what is usually observed in this setting is the decline of the existing species and the increase of the new species.




i'm sorry if my explanations aren't very good. my mind is tired. i'm trying to type a lab report right now...
but i hope this helped.

[esm90]

1. I don't know if there's one obvious answer, but a succession is a change in communities (replacement of one community by another over time). Evolution is a change in species.

2. Lives go away, but life itself doesn't go away. Even if a forest fire destroys all lives in the forest ecosystem, eventually there will be a new ecosystem starting there (secondary succession). The whole idea of secondary, tertiary, etc successions is one ecosystem replacing another.

3. Try reading this: http://www.cbu.edu/~seisen/Succession/sld001.htm (I think there are different things you can say for different ecosystems)

edit: nvm, the answer above is probably better

[Vivskies]

;o Yeah. Thanks guys!


blah, 20 minimum req