Environmental Science 3300F/G Lecture Notes - Lecture 2: Geosphere, Decomposer, Cellular Respiration
12 Dec 2017
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Levels of organization in nature: realm of ecology, ecosphere, ecosystems, communities, populations, organisms. Scientists estimate 3. 6 million to 100 million species exist: right now, 2 million have been discovered, half of those are insects, the more conservative estimate sits around 10-14 million. What species rule the world: microorganisms are the key to life on earth, microbes for example (bacteria, fungi & yeast, help you digest food, clean water, act as natural pesticides, are essential for life. What is a population: populations are groups of organisms of the same species living in the same habitat, populations have genetic diversity, this sets the stage for natural selection. Same geographic area: does(cid:374)"t have to be a continent or a huge size, could be something like a group of bugs living on one tree. What is a community: populations of different species living and interacting in the same area, communities are always changing through succession, species composition changing through time.
