What class is this? A.) biology B.) biology C.) biology D.) biology.
Biology
3
Biology Exam 3 Lecture 2 3/30/15 12:55 PM Directional selection – individuals at one extreme of a character distribution contribute more offspring to the next generation Can be positive or negative directional selection Stabilizing selection is when the mean phenotype has the highest fitness and individuals with extreme phenotypes have the lowest fitness It reduces variation in populations, but does not change the mean. Disruptive selection – individuals at opposite extremes of a character distribution contribute more offspring to the next generation. Increases variation Positive frequency-dependent selection – the fitness of a phenotype increases as it becomes more common Distinct from stabilizing selection – any phenotype (not just intermediate phenotype) could be favored if it’s the most common Negative frequency-dependent selection (balancing selection): Fitness of a phenotype decreases as it becomes more common Leads to maintenance of polymorphism over time
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Transcript of Biology
3/30/15 12:55 PMDirectional selection individuals at one extreme of a character distribution contribute more offspring to the next generation Can be positive or negative directional selection
Stabilizing selection is when the mean phenotype has the highest fitness and individuals with extreme phenotypes have the lowest fitness
It reduces variation in populations, but does not change the mean.
Disruptive selection individuals at opposite extremes of a character distribution contribute more offspring to the next generation. Increases variation
Positive frequency-dependent selection the fitness of a phenotype increases as it becomes more common
Distinct from stabilizing selection any phenotype (not just intermediate phenotype) could be favored if its the most common
Negative frequency-dependent selection (balancing selection): Fitness of a phenotype decreases as it becomes more commonLeads to maintenance of polymorphism over time
Biology Exam 3 Lecture 23/30/15 12:55 PM
3/30/15 12:55 PM
