Exam 1 Flashcards
Natural Selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits
Inductive Reasoning
A type of logic in which generalizations are based on a large number of specific observations
Deductive Reasoning
A type of logic in which specific results are predicted from a general premise
Theory
An explanation that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence
Microevolution
Evolutionary change below the species level; change in the allele frequencies in a population over generations
Genetic Variation
Differences among individuals in the composition of their genes or other DNA sequences
Gene Variability
Genetic variation at the whole-gene level
Mutation
A change in the nucleotide sequence of an organism’s DNA
Neutral Variation
Genetic variation that does not provide a selective advantage or disadvantage
What are some of the main factors that alter genetic variation?
- Formation of new alleles
- Altering gene number or position
- Rapid reproduction
- Sexual reproduction (crossing over, independent assortment, fertilization)
Population
A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring
Gene Pool
The aggregate of all copies of every type of allele at all loci in every individual in a population. The term is also used in a more restricted sense as the aggregate of alleles for just one or a few loci in a population.
Hardy-Weinberg Equilibrium
The state of a population in which frequencies of alleles and genotypes remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work
Adaptive Evolution
A process in which traits that enhance survival or reproduction tend to increase in frequency in a population over time
Genetic Drift
A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next. Effects of genetic drift are most pronounced in small populations.
Founder Effect
Genetic drift that occurs when a few individuals become isolated from a larger population and form a new po;pulation whose gene pool composition is not reflective of that of the original population
Bottleneck Effect
Genetic drift that occurs when the size of a population is reduced, as by a natural disaster or human actions. Typically, the surviving population is no longer genetically representative of the original population.
Gene Flow
The transfer of alleles from one population to another, resulting from the movement of fertile individuals or their gametes