Vocab Unit 7 1,2,3,4,5,12 Flashcards
Biogeography
the branch of biology that deals with the geographical distribution of plants and animals
Natural Selection
the process through which populations of living organisms adapt and change
Biotic Factors
a living organism that shapes its environment.
Descent With Modification
the idea that species change over time, give rise to new species, and share a common ancestor.
Competition
the direct or indirect interaction of organisms that leads to a change in fitness when the organisms share the same resource.
Selective Pressures
external agents which affect an organism’s ability to survive in a given environment.
Adaptations
any heritable trait that helps an organism, such as a plant or animal, survive and reproduce in its environment.
Phenotype
The observable characteristics in an individual resulting from the expression of genes
Genotype
a scoring of the type of variant present at a given location (i.e., a locus) in the genome.
Artificial Selection
the identification by humans of desirable traits in plants and animals, and the steps taken to enhance and perpetuate those traits in future generations.
Mutation
is a change in the DNA sequence of an organism.
Population
a group of organisms of one species that interbreed and live in the same place at the same time.
Gene Pool
the combination of all the genes (including alleles) present in a reproducing population or species.
Fixed
a chemical treatment of tissue or Cells that results in preservation.
Genetic Drift
a mechanism of evolution characterized by random fluctuations in the frequency of a particular version of a gene (allele) in a population.
Bottleneck Effect
an extreme example of genetic drift that happens when the size of a population is severely reduced.
Founder Effect
the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population.
Gene Flow
the introduction of genetic material (by interbreeding) from one population of a species to another
Directional Selection
when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other.
Stabilizing Selection
a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value.
Disruptive Selection
when individuals of intermediate phenotype are less fit than those of both higher and lower phenotype, such that extremes are favored.
Sexual Selection
the process by which individuals compete for access to mates and fertilization opportunities.
Hardy Weinberg equilibrium
principle stating that the genetic variation in a population will remain constant from one generation to the next
