mechanism of evolution Flashcards
what does genetic traits present in a population make up
gene pool
are successful traits more common within a population?
YES
What changes alleles frequencies within populations?
mutations
Gene flow
Non-random meeting
Genetic drift
natural selection
what are mutations? and example
change in the
DNA of an individual
warfarin in rats
what is gene flow
movement of alleles from one
population to another
what is non-random mating
Mating based on choosing a partner with a specific (phenotype
what is preferred phenotypes
Choosing a mate based on physical traits
what is sexual selection
natural selection for meeting
-competition between males to be chosenby females
what is genetic drift?
Change of frequencies of alleles
What is the founder effect?
change in gene pool when new population starts
what is a bottleneck affect? what is it caused by
Changes in gene distribution that happens from a decrease in population
caused by starvation disease, natural disaster
gene pool loses what?
diversity
what are the three types of natural selection
Stabilizing selection
– Directional selection
– Disruptive selection
What is stabilizing selection? what does it act against and example?
Favours individuals near middle of range
Birthweight
acts againsnt extrme variant of phenotypes
what is directional selection and example? what does it result it
Favours phenotypes at one end of range
Can occur as an adaptation
Example, darker colour of moth
results in shifted range of phenotypes
What is disruptive selection and example? what does it eliminate
favours both extremes of the range and eliminates intermediate phenotypes
example tail length and squirrels
eliminates intermediate phenotypes
what is sexual dimorphism
when females and males in a species have different traits
