Quiz 2 study guide

Below is a general outline of the information covered on quiz 2

• Principle of Evolution #2 - Animals of different types form populations (this happens by different methods of Isolation)
• Prezygotic - which includes Allopatric (geographical), and most Sympatric (same location) Isolation
• Allopatric Isolation- (already covered on quiz 1) *remember these populations live in different areas so this is a very effective way of preventing a zygote
• long distance dispersal - colonization
• barrier formation - vicariance - caused by geographical barriers
• population fragmentation - caused by environmental changes
• Sympatric Isolation - these populations (not individuals) live in the same area but are isolated in different ways listed below:
• Ecological Isolation - also called Niche Partitioning (Segregation)
• Random Selection - this is the idea that the characteristics of a populations niche can be random
• Competition - don't get this confused with Predation - competition occurs between two populations when resources overlap (competition for a resource)
• Convince - close inexpensive resources allow a low energy, safe lifestyle where mates are readily available
• Symbiotic - relationships between neighboring populations that are not harmful to either population
• Mutualism - both populations benefit from relationship
• Commensalism - one population benefits and the other is not affected by the relationship
• Exploitation - relationships between neighboring populations that always create a winner and a looser
• Herbivory
• Parasitic
• Predation
• Behavioral - potential mates recognize behaviors which keeps different types of populations isolated - think of bird songs, dances, and other strange behavior that would cause this isolation between populations
• Temporal - this is the isolation of populations created by time. Seasonal or day activities including mating cause isolation between different types of populations. Why don't hawks breed with owls? (obviously there are many reasons but one could be that they would never come into contact because they are not awake at the same time of day)
• Mechanical - populations are isolated because of physical restrictions (size, or structurally) this nearly eliminates any possibility for breeding between populations
• Gamete Incompatibility - gametes are incompatible for any number of reasons including the lack of attractive chemicals produced by an egg or the inability to recognize the chemicals by the sperm. Incompatible internal environment may also cause problems for the sperm, thus stopping any possibility for the creation of a zygote
• Postzygotic Isolation - don't forget that this is a method of Sympatric Isolation - this type of isolation occurs when there was a zygote formed (the sperm was able to get into the egg)
• The zygote may not develop properly
• The zygote may form but be infertile
• The zygote may be less fit than either parental population and unable to compete for resources
• The zygote may be "unattractive" (either behaviorally or physically because it is a blended combination of two populations) and unable to find a mate

Some questions you may want to think about in preparation for the quiz:

1. What is the difference between the fundamental and realized niche?
2. What happens when resource overlap doesn't work? How does this affect my realized niche?
3. What factors promote niche segregation?
4. What are the most effective ways of Prezygotic Isolation? (think about which isolation methods never have a zygote form)
5. When does predation play a role in competition? (remember these are not the same thing)
6. If there are plenty of resources available does my fundamental niche expand? Does my realized niche expand?
7. What caused the decline of woodpecker populations? What caused the increase in populations?