Unit 4 summary 5 Flashcards
Gene pool
Gene pool: The sum of alleles present in a population
Species
Species: Organisms are of the same species if they can interbreed to produce viable, fertile offspring
Population
Population: Members of one species living in one region at a particular time
Genetic variation
Genetic variation: Trait in which different organisms or members of a population or species display different phenotypes
Allele frequency
Allele frequency: the relative number of an allele in a population
Evolution
Evolution: the process of gradual change in a population of organisms that results in new species
Mutation
Mutation: change in nucleotide sequence in a gene or chromosome. ie deletion, addition, translocation, substitution
Gene flow
Gene flow: migration of individuals, and their genes, between populations
Immigration
Immigration: entering the population
Emmigration
Emigration: leaving (exiting) the population
Genetic drift
Genetic drift: changes in allele frequencies due to random chance events
Founder effect
Founder effect: The establishment of a new population by a few original founders which carry only a small fraction of the total genetic variation of the parental population
Population bottleneck
Population bottleneck: population is reduced due to disaster, as such the small population is not representative of the original population
Environmental selection pressures
Environmental selection pressures: The extent to which organisms possessing a particular characteristic are either eliminated or favoured by environmental demands. It indicates the degree of intensity of natural selection.
Natural selection
Natural selection: a natural process that occurs in ecosystems where, at a particular time, certain members of a species that are more suited to the prevailing conditions within that given area are more likely to reproduce and pass on their alleles to the next generation.
Biological fitness
Biological fitness: the measure of biological success of an organism in terms of the number of viable offspring it produces.
Selection pressure
Selection pressure: a factor, usually environmental, that reduces the fitness of a particular phenotype in a population of organisms.
Adaptation
Adaptation: a feature of an organism that helps it to survive/ live long enough to produce viable offspring. (structural, behavioural, physiological.)
Artificial selection
Artificial selection: the selection by breeders of animals or plants with desirable phenotypes (and genotypes) for selective breeding to produce individuals with specific characteristics.
