Exam 4 Flashcards
What is intrasexual selection?
Competition between individuals of one sex (usually males) for the right to mate
Intrasexual selection often involves ritualized displays of dominance.
What is intersexual selection?
Mate choice where one gender selects a mate based on certain qualities
Qualities may include coloration, vocal qualities, and dominance.
What is coprophagy?
The act of eating feces
It can influence nutrient uptake and health outcomes.
What is a mutation?
A small change in the genetic material that can have significant effects
Example: Sickle cell anemia is caused by a change in one nucleotide in the hemoglobin gene.
What does homozygous mean in the context of sickle cell anemia?
Having two copies of the sickle cell allele, which causes the disease
Homozygous individuals are affected by sickle cell anemia.
What does heterozygous mean in the context of sickle cell anemia?
Having one normal allele and one sickle cell allele, which confers resistance to malaria
This is an example of heterozygote advantage.
What is pleiotropy?
The phenomenon where one gene influences multiple phenotypic traits
In sickle cell anemia, the sickled hemoglobin can lead to various health effects.
What is heterozygote protection?
The concept that heterozygous phenotypes are more fit than homozygous phenotypes
This often results in the harmful homozygous individuals being removed from the gene pool.
What are beneficial mutations?
Mutations that enhance survival or reproductive success, leading to increased frequency in a population
These mutations contribute positively to the fitness of individuals.
How do mutations affect a population?
They serve as a source of new alleles
This can influence genetic diversity within the population.
What is nucleotide diversity?
The variation in nucleotide sequences among individuals
Humans are approximately 99% genetically similar to chimpanzees.
What are neutral variations?
Genetic variations that do not impact reproductive success
Example: Fingerprints are considered neutral variations.
What factors increase variability in a population?
- Mutation
- Recombination (random breeding)
- Gene flow
These processes contribute to genetic diversity.
What factors decrease variability in a population?
- Natural selection
- Genetic drift
- Non-random breeding
These processes can reduce genetic diversity.
What does fitness refer to in evolutionary terms?
An individual’s reproductive success
Fitness can be absolute or relative.