Population Genetics Flashcards
(22 cards)
Population
an interbreeding group of organisms or species that occupies a particular area
Gene Pool
collection of all alleles of all the genes found within a freely interbreeding population
Genetic Drift
random changes in the allele frequency of any population. it is more obvious in small populations
natural selection
Individuals who are better adapted are more likely to survive
Deme
a subdivision of a population consisting of closely related plants, animals, or people, typically breeding mainly within the group.
Geographical barrier
A geographical barrier is something that blocks the pathway to something, this can be any natural feature such as mountains that prevents easy movement from one place to another.
Gene flow
The movement of alleles between individuals of different populations; includes the dispersal of pollen and seeds in plants
Mutation
a permanent change in a genetic sequence, including changes to the nucleotide sequence of DNA or chromosomal arrangement . Can have a beneficial, harmful or no effect on survival ability of individual
Immigration
rate at which individuals enter or leave a population.
act or process of moving to another region with the intent of residing
Emigration
leaving of a place of residence or habitat with the intent of living in another place
founder effect
occurs when a small portion of a population disperses to a new location and becomes genetically isolated from the main population
allele frequency
the relative proportion of a particular allele in a gene pool. typically presented as a decimal or percentage of the allele of that gene in the gene pool
phenotype
the observable trait; expression of a genotype in an individual for a particular trait . The dominance of alleles and the environmental conditions influence the phenotype of an individual
eg nutrient availability may influence the pigment synthesis of flower petals or hair follicles in animals
alleles
different forms of a gene
eg a gene that codes for hairline shape in humans has two alleles- straight and widows peak
diversity
the variability among living organisms from all sources
population bottle necks
sharp reduction in the size of a population due to environmental events (such as famines, earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide).
endangered species
A plant or animal species existing in such small numbers that it is in danger of becoming extinct, especially such a species placed in jeopardy as a result of human activity. One of the principal factors in the endangerment or extinction of a species is the destruction or pollution of its native habitat.
catastrophic event
Any natural or man-made incident, including terrorism, which results in extraordinary levels of mass casualties, damage, or disruption severely affecting the population, infrastructure, environment, economy, national morale, and/or government functions.
susceptible to disease
member of a population who is at risk of becoming infected by a disease.
lost alleles
A population bottleneck is an event that drastically reduces the size of a population. … The population bottleneck produces a decrease in the gene pool of the population because many alleles, or gene variants, that were present in the original population are lost, meaning they arent evident in the population anymore
fixed alleles
A fixed allele is an allele that is the only variant that exists for that gene in all the population. A fixed allele is homozygous for all members of the population.
evolution of new species
Speciation is the process by which new species form. It occurs when groups in a species become reproductively isolated and diverge. In allopatric speciation, groups from an ancestral population evolve into separate species due to a period of geographical separation.
