Population Change Flashcards
What is a population?
All the members of a species that occupy a particular area at a specific time
same time, same species, same place
What is evolution?
Change in the frequency of genes in a population’s gene pool from one generation to the next
What is a gene pool?
total genes in all the members of a population at one time
What is the Hardy Weinburg Principle used for?
To quantify an unchanging gene pool
What are the 5 conditions for the Hardy Weinburg Principle?
no natural selection
no mutations
no migration
random mating
large population
What is stability called?
Genetic equilibrium
What is micro evolution?
a change in the gene pool of a population over successive generations
What is micro evolution?
Changes in a gene pool over successive generations
Describe the changes in gene pool:
natural selection: greater reproductive success, increase frequency of its alleles
mutations: substitution of an allele immediately changes gene pool
migration: remove alleles, add to another, gene flow: movement of allele to a different population by moving an individual or gamete
non-random mating: sexual dimorphism, sexual selection favours a trait that increases mating success
small population: genetic drift: change in gene pool from chance, decrease genetic diversity, founder effect and bottleneck effect, chance fluctuations
What is sexual dimorphism?
difference in male physical appearance and female behaviours (species display different characteristics)
What is gene flow?
migration, movement of alleles to a different population by individuals or gamete movement
What is genetic drift?
small population, change in the gene pool from chance, can decrease genetic diversity
founder effect: small number of individuals move from their OG population to a new one
bottleneck effect: dramatic, temporary decrease in population
What is the formula for population density?
Dp = number of individuals (N)/area of volume (A/V)
How do you determine change in population size?
Change in population size = (factors that increase pop) - (factors that decrease pop)
= (births and immigration) - (deaths and emigration)
How do you determine growth rate?
gr = change in population size / time
how quickly a population is increasing or decreasing
