13.9, onwards Evolutionary Problems Flashcards
Population
a group of individuals belonging to one species that live in the same area and can inbreed
Gene Pool
all of the genes/alleles in a population
Allele Frequency
the percentage of an allele that exists in a population
Evolution is aka
microevolution
Microevolution
change in the frequency of alleles in a population over time
How many causes are there for Evolutionary Change
3
What are the 3 causes for Evolutionary Change
natural selection, genetic drift, and gene flow
Genetic Drift
the change in the frequency of alleles in a population over a period of time due to chance
How many types of genetic drift are there
2
What are the 2 types of genetic drift
1) Bottleneck effect
2) Founder Effect
Bottleneck Effect
genetic drift by chance ~ completely random
What is an example of the bottleneck effect
natural disasters
founder effect
when individuals in a population end up in a different area (uninhabited by that population) by chance and they are successful and reproduce
How did Darwin explain the finches on the Galapagos Islands
founder effect
What is an example of the founder effect
invasive species
Gene Flow
the transfer of alleles from one population to another as a result of the movement of individuals or their gametes
Genetic Equilibrium
when the frequency of alleles doesn’t change over a period of time
what is the opposite of genetic equilibirum
evolution
Who discovered genetic equilibirum
Hardy and Weinberg
Hardy-Weinberg Principle
if all Hardy-Weinberg conditions are met then there will be no change in frequency of alleles over a period of time
Hardy-Weinberg Principle is about _____ not ______
genes;populations
What are the Hardy-Weinberg Conditions
- random mating
- large population size
- no immigration or emigration
- no mutations
- no natural selection
How many Hardy-Weinberg conditions are there
5
Random mating
mating without choice, not because of attraction etc.
large population size
need an “infinitely” large population (large is relative to population size )
How many Hardy-Weinberg equations are there
2
What are the Hardy-Weinberg equations
Allele frequency equation and genotype frequency equation
Allele frequency Equation
p + q = 1
Genotype Frequency Equation
p² + 2pq + q² = 1
What does the p stand for in the allele frequency equation
the frequency of the dominant allele
What does the q stand for in the genotype frequency equation
frequency of the recessive allele
What does the p² stand for in the genotype frequency equation
frequency of homozygous dominant genotype
What does the 2pq stand for in the genotype frequency equation
frequency of the heterozygous genotype
What does the q² stand for in the genotype frequency equation
frequency of homozygous recessive genotype
Single Gene traits
traits controlled by a single gene
Polygenic traits
traits that are controlled by more than one gene which creates more variation because there are more possible combinations
Natural selection on single gene traits
people with the more benificial trait will reproduce and make more organisms with that trait
What kind of graph does natural selection on single gene traits have
standard one up one down
Natural Selection on Polygenic traits
there is a high amount of beneficial traits, lower not so beneficial
How many types of Natural Selection on Polygenic traits are there
3
What are the 3 types of Natural Selection on Polygenic traits
1) Stabilizing Selection
2) Directional Selection
3) Disruptive Selection
Stabilizing Selection
changes in environment where different organisms are fit
Disruptive selection is aka
diversifying selection
Stablizing Selection is more likely to create
a different species
all Natural Selection on Polygenic traits graphs are
bell curved
Sexual Selection
whne organisms select their mates based on certain characteristics
How many types of sexual selection are there
2
What are the 2 types of sexual selection
Intrasexual and Intersexual
Sexual Dimorphism
there is a clear difference between male and female structures
Intersexual Selection
female chooses male based on characteristics
Intrasexual Selection
males fight and the better/stronger male gets the female
do males actually fight in intrasexual selection
no, usually thye just size each other up bc fighting causes pain
Evolution of drug resistant microorganisms
there are antibiotic resistant bacteria that are killed if you take antibiotics bc they kill the weaker bacteria which allow the already antibiotic bacteria to thrive
Balancing Selection
if there is no trait that is more beneficial than another, there will be a balance of the traits
Balancing Selection is aka
balance polymorphism
Heterozygote Advantage
its better to be heterozygous for a trait rather than homozygous recessive/dominant
What are some examples of heterozygote advantage
sickle cell disease
Can natural selection fashion perfect organisms
no bc if the body is good at one thing, it will lose another factor
Darwin used the practice of _______________ to gain insight into his ideas about a mechanism for descent with modification.
artificial selection
