Natural Selection Vocabulary Review
Natural selection
Differential survival or
reproduction of individuals
facing environmental pressures
Variation
Characteristics (alleles) that
differ among individuals
Overproduction
Producing more offspring than
can survive
Selection pressure
Competition
Fitness
“pressure” the environment puts
on the specific traits that affects
their ability to survive
Struggle between individuals to
get the most resources for
themselves
how well an organism is at
having babies that survive to
reproduce
Predation
Killing and eating prey by a
predator
Mutation
Change in DNA that leads to a
new allele
Gene pool
All the alleles of all the genes in
a population
Gene (allele) frequency
Proportion of one type of allele in
the population
Gene flow
new alleles from one population
enter another
Genetic drift
Random change in allele
frequency
Bottleneck
Random event that radically
decreases population size
Founder effect
A new population started by a
small number of individuals
Species
Sexual selection
Speciation
Geographic isolation
Reproductive isolation
adaptation
a group of orgs. that interbreed
under natural conditions to
produce fertile offspring
“special case” of natural
selection; pressures that affect
an individual’s success in mating
Splitting of one species into two
or more different species
members of a species are isolated
from one another due to a
geographic barrier
members of a species are isolated
from one another due to a
reproductive barrier
A characteristic that helps an
organism survive in its
environment