BIO chap 17 Questions Flashcards
What is variation in Natural populations?
We are trying to understand what level is coded for genetic variation and which is coded for environmental variation
What is Phenotypic variation?
Heritable variation in appearance/function (behaviour)
What is Phenotypic plasticity?
When two individuals have the exact same genotype but are placed in different environments which leads them to having different phenotypic traits because they’re expressed differently based on their enviornement.
What is Quantitative variation?
When individuals differ in small incremental ways. On a frequency distribution. If you notice a low broad curve that indicates their is a lot of variation among individuals but if you notice a high peak curve, that indicates there is very few variation among individuals
What is Qualitative variation?
Characteristics with discrete states (two diff things like orange and blue)
What is polymorphism?
Individuals with discrete characteristics but within the same species like birds with different colours (example of qualitative)
Are genotypes and phenotypes always correlated?
No
Phenotypic variation is due to genetics, environment or the interaction of the two
Give an example on how genotypes and phenotypes are not always correlated
You have the two flower seeds with the same genotype. One grows to be blue and the other grows to be pink. This is because they grew on different environments. Blue grew on acidic soil and pink grew on Alkaline soil
What is standing genetic variation?
Variation that exists within a population that may not be selected on now, but later if the environment changes, it can be used
What is a genetic structure?
When a population gets isolated and start mating with one another which in other terms is inbred. And this made the population really similar genetically. Everyone had the same kind of alleles
What is the Hardy-Weinberg principle?
When a population is not evolving. It’ll be considered in HW if it is not.
What is genetic variation?
When individuals posses different versions of the same genes. Can happen through production of new alleles or rearrangement of existing alleles leading to new recombination’s
What is a locus?
Location of a gene on a chromosome
What is a gene pool?
All alleles at all loci in a population
What is SNPs?
Difference in amino acid sequences which indicates difference amongst individuals. Normally a single nucleotide polymorphism
What is genotype frequency?
Percentage of individuals possessing genotype
What is allele frequency?
Calculated from genotype in diploid organisms
P & Q: two different alleles at a locus
What happens if conditions are met in HW?
Microevolution does not occur
What happens if conditions are NOT met in HW?
Microevolution does occur
What are some conditions that can prove evolution is not happening?
- No mutations occurring in the population
- Population is closed to migration
- All genotypes free of selection
- Population infinite in size
- Random mating with respect to genotype
What are the effects of blind luck when it comes to picking random gametes from a pool?
Each time you pull different gametes from a gamete pool, you will get a different ratio of alleles. This will cause a population to evolve in an unpredictable manner.
What does it mean when you have the same allele initial frequency and same allele final frequency?
That means evolution is not happening within a population and the population is in HW
What if genetic drift?
Subtle change in frequency because of random chance.
Ex. the idea of picking random gametes from a gamete pool resulting in a slightly changed final allele frequency
What is the HW equilibrium?
Frequency of homozygote dominant genotype (p^2) + Frequency of heterozygote genotype (2pq) + Frequency of homozygote recessive genotype (q^2) = 1
What are HW’s 5 assumptions?
- No mutation (no new alleles have been created which means a lack in different allele
- No NS (all individuals survive at equal rates and individuals contribute equal number of gametes in the gene pool)
- No migration (individuals do not move in or out of population, no gene flow)
- No chance events ( idea of passing alleles onto the next generation , blind luck plays no role)
- Individuals choose their mates at random (gametes find each other randomly)
What happens if “no mutation” is violated?
Allele frequency will change within a population which means evolution is happening
What happens if “no NS” is violated?
That means that some individuals with some genotypes with survive over others and reproduce which leads to a change in allele frequency
What happens if “no migration” is violated?
Individuals will be carrying high frequency alleles out of the population which will allow allele frequencies to change and also allow gene flow
What happens if “ no chance events” is violated?
Genetic drift, allele frequencies will change
What happens if “individuals choose their mates at random” is violated?
Individuals prefer to mate with individuals with the same genotypes. This can cause loss of fitness because inbreeding increases homozygotes like AA and aa and decreases heterozygotes like Aa which is not good for fitness.
What are the four agents of Microevolution? (Drives population OUT of HW)
- Gene flow
- Genetic drift
- Mutations
- Natural Selection
