Chapter 24 Population Genetics Flashcards
heritable change in one or more characteristics of a population over time.
Biological Evolution
group of individuals of the same species that occupy the same environment at the same time.
Population
All of the alleles for every gene in a given population make up the population’s…
Gene Pool
mathematical calculation calculated as the number of copies of a specific allele in a given population divided by the total number of alleles for that gene in a population.
Allele Frequency
mathematical calculation calculated as the number of individuals with a particular genotype in a given population divided by the total number of individuals in a population.
Genotype Frequency
if 5 criteria are met (see bullet list on pg. 481) then the allele and genotype frequencies for a given population will remain stable and unchanged.
Hardy-Weingberg equation
Changes in a population’s gene pool
Microevolution
the process in which individuals with certain heritable traits tend to survive and reproduce at a greater rate than those without those traits (sometimes known as survival of the fittest).
Natural Selection
changes in populations that increase their ability to survive and reproduce in a particular environment.
Adaptations
the relative likelihood that its genotype will contribute to the gene pool of the next generation.
An organism’s “fitness”
changes in allele frequency in a population due to random chance.
Genetic Drift
the result of drastic reduction of the size of the gene pool due things such as hunting, environmental catastrophe, etc.
Bottleneck Effect
the result of a small group of individuals separating from a larger population and establishing a new population
Founder Effect
Because the results of gene drift do not result in adaptation of the population for a given environment it is sometimes referred to as…
neutral variation / non-Darwinian evolution (or survival of the luckiest).
the transfer of alleles into or out of a population.
Gene Flow
a situation in which mates are chosen, rather than one in which the likelihood of a mating between any two individuals is equally likely (a specific example of this is inbreeding).
Nonrandom Mating
Theory of Biological Evolution
Genetic change in a Population over time
Microevolution
What determines how a species changes over time. Doesn’t necessarily mean “small” or short time period.
Macroevolution
Speciation–Where do new species come from? Doesn’t necessarily mean “big” change or “long” time period.
Evolution assumes
Life already existed. Doesn’t explain where the first thing came from.
Hardy-Weinberg Equilibrium
Mathematical model that predicts that allele frequencies within a population’s gene pool are inherently stable.
5 Parts of Hardy-Weinberg Equilibrium
- No mutations occur
- No selection occurs (none can be better at reproduction)
- Population is large (so no drift occurs)
- No migration occurs
- Mating is random
When microevolution is taking place…
Alleles frequencies in a population are changing over time.
Mutation
Source of all new alleles
Relatively low rates in eukaryotic organisms
