Chapter 9: Genetic Variation and Inbreeding Flashcards
founder effect
the original population could give rise to different founder populations
genetic variation
the difference in the genetic makeup (DNA) of individuals or populations among the same species
genetic variation is important for….
survival & adaptation
what does genetic variation help with?
helps in terms of natural selection and evolution
genetic variation
measure of the genetic differences within individuals or population
genetic diversity
the genetic variation of an entire species
Tasmanian devils
- loss of genetic variation near ext.
- devil facial tumor disease
- contagious cancer
- cancer cells do not recognize as foreign and proliferate
effective population size variable
Ne
effective population size
the number of individuals that effectively participates in producing the next generation
which is smaller - effective population size or census size?
effective population size
small Ne
bigger increase in genetic drift
Ne and sex ratio
Ne is highest at equal breeding sex ratio
types of genetic variation
- intrapopulation
- interpopulation
intrapopulation
- within population
- amount of variation within the members of a species in the same area
interpopulations
- between populations
- comparing two or more populations of a species
what determines levels of genetic variation in populations?
- mutation
- genetic drift
- gene flow
- sexual selection
- natural selection
levels of genetic variation that cause rapid and powerful phenotypic changes on management-relevant time scales
- genetic drift
- gene flow
- natural selections
mutation definition
random change in the DNA of a gene
mutation functions
- can form new allele
- can be passed on to offspring if in reproductive cells
genetic drift
- change in allele frequencies by chance
- genetic drift causes a loss of genetic diversity
- it is most common in small populations
what can lead to genetic drift
a population bottleneck
when does a bottle neck occur?
when an event drastically reduces population size
is Ne greater or smaller than N
Ne < N
how to measure genetic drift?
- depends on the effective population size
- essentially the number of individuals in a population who contribute offspring to the next generation
gene flow definition
the movement of alleles between population