D4.1 - Natural Selection Flashcards
(18 cards)
requirements of natural selection
overproduction of offspring
variation
survival of the ifttest
advantageous traits become more frequent
sources of variation
mutations
sexual reproduction
meiosis
what creates variation
alleles, crossing over, random orientation
what provides advatnges for sexually reproducing organisims in changing environments
variation
overproduction of offspring
more offspring produced than will be supported by environment
consequences of overproduction of offspring
interspecific competition due to limited space, resources and mates
abiotic selection factors
density independent or density dependent
density dependent abiotic selection factors
soil mineral availability
access to water
density independent abiotic selection factors
freezing
hot temp
natural disaster
salinity
influence of selection pressures
give advantages to individuals with certain variations
fitness
heritable factors that influence survival or reproductions in an ecological niche
influence of fitness
longer survival
more reproduction
greater contribution to gene pool
acquired traits
can help individual survive and reproduce but will not pass down to offspring
why are acquired traits not passed down to offspring
acquired traits do not change base sequences,
evolutionary change require …
heritability
sexual selection
identifying and choosing potential mates that are best adapted and likely to produce offspring that are also well adapted
what drives courtship behaviors in birds
sexual selection
visual & behavioral signs of fitness
results of john endler experiment with guppies
females preferred colored males
colored males more vulnerable to predators
high predator concentration = less colored males
low predator concentration = more colored males
