Evolution Flashcards
what is evolution?
change over time in the proportion of individuals in a population
differing in one or more inherited traits
what is an example of a random process
genetic drift
mutations
what is an example of a non random process
natural selection
sexual selection
what is the disadvantage of a small population?
genetic drift is more important
alleles are more likely to be lost from the gene pool
what is a mutation
variations of traits
from new sequence of DNA to form new alleles
beneficial, no change, effect
what is genetic drift?
change in populations allele frequency due to chance
what can shrink a population
bottleneck effect
founder effect
what is the bottleneck effect?
size of initial population reduced eg natural disaster
genetic variation is different from initial population
alleles over represented
alleles under represented
what is the founder effect?
few individuals from a large population
colonies another habitat
alleles in new population, not represent original
what is natural selection?
environmental conditions determine which individuals in a population produce the most offspring
accumulates favourable genotypes
what are the two types of sexual selection?
intersexual
intrasexual
what is intrasexual selection?
selection between same sex
compete with each other
warn off competition
what us intersexual selection?
females being selective about their choice of male
what is sexual dimorphism?
distinct difference in size or appearance between the sexes of animals in addition of sexual organs
