APES Chapter 4 Notes
Every living organisms have limited on where it can exist. Aquatic organisms have much smaller tolerance levels then other animals.
Organisms require different characteristics in their environment in order to survive. Examples include: temperature, moisture levels, nutrient supply, soil and water chemistry, or living space.
Our understanding of science has improved.
Factors determine where organisms can live, and it is determined by tolerance limits. One factor could determine more than any other factor the abundance and distribution of a species in a certain area.
Species (single organism) can go into an environment and acclimate by changing behavior.
Evolution requires many generations in a species for change. ***Natural selection***
Climate, humans, geology all contribute to evolution.
Natural selection is where certain genetic codes are favored over others.
Evolution acts on preexisting genetic diversity
Some of these changes are going to be advantages and others will be disadvantages. (Fluke gone right)
Physiological stress, predation, competition, and luck can cause selective pressure and influence fertility or survivorship.
Given enough geographic isolation or selective pressures, members of a population can become a whole different species.
Darwin studied finches at the Galapagos islands.
Natural selection is the natural situation in which one or a few individuals are given an advantage over others with certain characteristics.
Over time, populations can become separated through geographical isolation and make a new species (speciation) because they evolved differently. (Divergent evolution)
Unrelated species can evolve similarly if they have 100s of miles away because they occupy the same niche. (Convergent evolution) ex. Flying squirrel (Often confused with coevolution; very different things)
The place where an organisms lives and the condition of that place is a habitat
A niche is like an organisms occupation inside that habitat (What role they play in that habitat)
Every species has a set of chemical and physical characteristics in which they exist.
Niches can evolve with physical characteristics of an organisms.
Law of competitive exclusion: no two species can occupy the same niche and compete for the same resources in the same habitat and survive. Also called Gauseās principal. They partition off the resources they use, occupying the same habitat, but using different parts of it (resource partitioning).
Species interact with each other (Community dynamics) ex. Moose eating grass, Lion eating hyena
Any type of organism that eats another organisms (Predation)
- Parasites (weaken the host)
- Pathogens (viruses)
Predation is heathy on an ecosystem level, keeping the balance. Typically the animals eaten are either sick or weak or old
Sometimes within the same species, they also partition resources (ex. Baby butterfly eating leaves, adult eating nectar)
Species interactions can also be predator and prey relationships and it also gives better genes to the offspring
Coevolution is the process where species exert specific pressure on each other. The species may both evolve to better suit their needs. \n Keystone species-Species or set of species whose impact on its community or ecosystem is much larger and more influential than would be expected from mere abundanceĀ
By removing one organism, an ecosystem can become unbalanced, that one organisms that has a large impact is a keystone species.Ā
Reintroducing animals back into an ecosystem can also help an ecosystem- also a keystone species.
Flagship species-species that gets protected because it is cute to humans.
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