Evolution Flashcards
Evolution is…
Process by which populations have changed over time in response to changing environment
The parameters for natural selection are…
- diversity based on inheritable traits
- exhibit reproductive potential
- live in environments with limited resources
- competition for limited resources
- takes time (generations)
Natural selection is…
Mechanism for evolution, nature selects for the most advantageous traits (greater reproductive success in an environment)
Descent with modification is…
all organisms are related through a common ancestor - developed modifications for changing environments
Sexual Dimorphism
differences in phenotype between males & females of the same species
Genetic drift
changes in frequencies due to chance - either bottleneck effect or founder effect
Hardy-Weinberg equilibrium
when a pop is not evolving and the gene pool is at equilibrium (opposite of conditions for evolution)
Evolution caused by:
mutations, non-random mating, gene flow, genetic drift, natural selection
Directional Selection
One of the extreme phenotypes is favored (selection against other extreme)
Stabilizing Selection
Intermediate phenotype is favored (selection against extremes)
Speciation
When two populations of the same species remain isolated from each other and eventually change enough so that they cannot produce viable fertile offspring (no longer the same species)
Biodiversity
function of speciation and extinction
Morphological Homologies
Similar in structure and form
Vestigial Structure
Inherited from an ancestor, but now less complex & functional
Molecular Homologies
Similarities between species on a molecular level