variations
what are variations?
different colors, etc, within the same species
what is natural selection?
a mechanism of evolution where organisms that are better suited for their environment (favourable traits) survive and reproduce
what is evolution?
a change overtime
what are the types of evolution?
convergent, divergent, and coevolution
what are trait changes?
traits and allele frequencies that change over time in different ways
what are variations caused by?
either genetic factors or enviornmental influences (physical/phenotypic, behavorial, amd genetic)
what conditions are required for natural selection? why?
overproduction of offspring - more genetic variation
struggle to survive - different reproductive success
wht are the 2 main mechanisms?
genetic drift and natural selection
what is convergent evolution?
to converge into one - evolution toward similar characteristics with no common ancestors, ex: wings that look different w same function
what are the types of trait changes?
directional, stabilizing, and disruptive
what do phenotypic variations do for the rate of survival?
some animals may have more favourable physical traits for a certain environment, like camouflage, therefore live to reproduce and pass that down (natural selection)
what can overproduction lead to?
increases chance of variations, but also creates competition for food
what is genetic drift?
essentially a change in alleles by change rather than something like natural selection. traits are COMPLETELY random, and have no correlation to the environment
what is divergent evolution?
a split or branch - when closely related species evolve in different directions, same common ancestor but develop traits bc of different enviornments and situations
what do directional trait changes do?
population's traits shift toward 1 direction toward an extreme trait, less genetic diversity
what do genetic variations do for the rate of survival?
some animals may have more favourable alleles/traits for a certain environment, like poison resistance, therefore live to reproduce and pass that down (natural selection)
whats a gene pool?
a set of all possible genetic info and combinations of any population of a species, smaller gene pools and less genetic diversity is easier to wipe out
how is speciation relevant to divergent evolution?
because 1 species is splitting into 2 or more, making it impossible to breed bc theyre so different
what do stabilizing traits do?
they stabilize 2 traits within a population and select AGAINST 2 extremes, less diversity bc anything too extreme is wiped
where do genetic variations come from?
they are transferred from both parents to the offspring and gets about 50/100 from each parent
what is coevolution?
together - 2 species evolve in correlation to eachother, prey evolves to get away from pred, pred then evolves to catch prey
what do disruptive traits do?
where BOTH extreme traits are favoured over the average trait, has 2 peaks