lesson 2 Flashcards
when the frequencies of alleles in a group undergo changes
Microevolution
process wherein different environmental pressures lead to different ways of survival and reproduction, which can influence the frequency of alleles in a group
Natural selection
occurs if the extreme forms of the traits are favored more than others
Disruptive selection
shifts alleles frequencies caused by the change in the condition of the environment
Directional selection
when a middle form of the trait is chosen and the extreme forms are eliminated
Stabilizing selection
a change in the gene pool of a group
Genetic drift
total collection of genes
Gene pool
different forms of a gene. Inherited from each parent. The genotype of a gene can be either dominant or recessive
Alleles
present when there is a change in the DNA of an organism, resulting in the formation of a new allele. Change in DNA happens randomly
Mutation
another agent of microevolution. Movement of alleles in a group of organisms. Occurs when fertile organisms move in or out of a specific group
Gene flow
Godfrey Hardy and Wilhelm Weinberg proposed this that states that the frequency of alleles in a gene pool will remain constant unless one or more factors or other agents will cause the frequency to change
Hardy-Weinberg equilibrium/genetic equilibrium
refers to the large scale changes that lead to an evolution of organisms from simple to complex
Macroevolution
shows how macroevolution happens for a long period of time. It also shows the transitions that occur in the
Geologic time scale
result of various factors; these factors all lead to the disappearance of a vast number of organisms.
Mass extinction
one possible thing that happened why organisms survive the mass extinction. Organisms evolve, and their existing body structures are used for new functions
Adaptation
