Evolution Flashcards
What is evolutiom
Change in dna over time
What causes variation in nature
DNA mutation/ natural selection
What happens to organism with favorable traits
Survive and reproduce
What happens to organisms with unfavorable traits
Die of
Natural selection
Organisms with favorable traits survive and reproduce vice versa
Artificial selection
Humans determine the best characteristics and make those survive and reproduce
Sexual selection
One sex favors a certain trait in the opposite sex and mate with them which makes that trait more common
Homologous structures
similar physical features in organisms that share a common ancestor, but the features serve completely different functions Ex whale bat
Fossils
Preserved remains of plants/animals
DNA and protein
Similar dna= closely related
Embryology
Similarities I’m unborn animals
Founder effect
Part of the population becomes separated from original population
Common ancestors
Organisms that have evolved from one species to different species
Vestigial structures
Once useful body parts that have expired use due to evolution example: whale walking fun
Bottleneck effect
Extreme reduction due to humans/ natural disaster
In nature why do most organisms have a stable population size
Natural selection, competition, lack of recources
Gene flow
Occurs when organisms move into or out of an environment, bringing their dna with them
Allele
One from mom one from dad :variation of a gene
Population
Organisms of a species living together in one particular place
Stabilizing selection
Favors the average traits
Directional selection
Favors the extreme traits
Diversifying selecfion
Selection toward both ends of the extremes
Aa
Heterozygous
AA
Homozygous dominant
aa
Homozygous recessive
In a population of 1300 crocodiles 400 appear short toothed which is a recessive trait
What percent is homozygous recessive?
What is the frequency of the dominant allele?
What percent of the population is heterozygous?
31%
44%
19%
49%
In owls 250 out of 700 adults have a dominant phenotype
What so the frequency of the recessive allele?
What is the frequency of the dominant allele?
What percent of owls are heterozygous
.8
.2
.32
In the scarlet tiger moth color is determined by two alleles. White is dominant and yellow is recessive. I’m a population 1607 are white 59 are yellow
Q2
Q
P
P2
2pq
.04
.2
.8
.64
.32
How many decimals do we round to
2
