Week #2 Flashcards
Humans and monkeys share a common _______?
Ancestor
What are some misconceptions of evolution?
Evolution is “just” a theory, Individuals evolve, Evolution explains the origin of life, Organisms evolved on purpose
What is evolution?
Process of change in a population of species over time
What are the two types of evolution?
Macroevolution and Microevolution
What is Macroevolution?
rise of new species (from old) and higher taxonomic groups with widely divergent characters (speciation)
What is Microevolution?
Change within a population ; Changes in heritable characteristics / allele / gene frequency over time; Can be observed over short periods of time
What are mechanisms of evolution?
Forces that change the genetic structure of a population
What are the 6 mechanisms of evolution?
Mutation; Natural selection; Gene flow (migration); Genetic drift (random); Recombination; Non-Random Mating; (“MaNaGGeRR”)
What is a mutation?
A rare change in DNA; Ultimate source or new alleles and genetic variation
T/F - All mutations are bad?
False
What is natural selection?
Differential survival and reproduction of individuals due to differences in phenotype / traits
Natural Selection acts on the ____?
Individual
Evolution acts on the ____?
Population
T/F - Natural selection and artificial selection are the same?
False
What is genetic variation?
Raw material for selection
What is gene flow?
The flow of alleles in and out of a population due to the migration of individuals or gametes; Can occur when an individual travels from one geographic location to another.
T/F - Genetic drift is intentional?
False, it is random
What is genetic drift?
allele frequencies within a population change randomly
T/F - Genetic drift increases genetic variation in small populations?
False, it reduces genetic variation in small populations
T/F - Genetic drift results in advantages to an existing population’s alleles?
False, there is no advantage considered since it is random
What are the two methods of genetic drift?
Population bottleneck and Founder’s effect
What is population bottleneck?
A chance event or catastrophe that can reduce the genetic variability within a population
Ex. Natural disaster
What is the Founder’s effect?
An allele frequency change in an isolated part of the population, which is not typical of the original population; Genetic makeup not representative of larger population left behind
What is recombination?
Combination of genetic material from two different gametes (crossing over and independent assortment); occurs from parents mating
What is non-random mating?
The probability that two individuals in a population will mate is not the same for all possible pairs of individuals; Preference for mates
What are the 5 types of selection?
Directional selection; Stabilizing; Disruptive; Intersexual; Intrasexual
What traits does sexual selection favor?
Traits that enhance reproductive success
What is directional selection?
A type of natural selection that causes a population to evolve toward one end of a trait spectrum
What is stabilizing selection?
A type of natural selection that favors individuals with average or moderate phenotypes
What is disruptive selection?
A type of natural selection where both extremes of a trait are favored over moderate trait
What is intersexual selection?
A type of natural selection where one sex chooses a mate from the opposite sex, based on their attraction to certain traits
What is intrasexual selection?
A type of natural selection that describes the competition between members of the same sex for access to mates
What is oscillating selection?
A type of natural selection where one phenotype is favored and then another is favored later depending on changing environmental conditions
