Lecture 4 Flashcards
(30 cards)
How does genetic variation happen?
- mutation
- recombination
- gene flow
- hybridization
What is the ultimate source of genetic variation?
mutation
what are point mutations?
base substitutions, insertions, deletions
Other than point mutations, what are the other mutation types?
- gene duplications
- changes in chromosome structure (inversions, translocations)
Are all mutations heritable?
no
What are somatic mutations?
affects cells in the body of an organism, not heritable
What are germ-line mutations?
affect gametes, heritable and relevant to evolution
Do all mutations affect proteins?
No
What type of regions make up most fo the genome?
non coding regions
If we have a mutations in a non coding region, how would that impact gene function?
can have implications for evolution, but would not really affect gene function
Are mutations that persist random?
No
Is mutation rate the same for all species?
No, it varies between species
What do mutation rates depend on?
depends on the type of mutation and among genes (depends if the gene have DNA repair mechanisms or tolerance for error)
How common are point mutations? What is their effect?
- most common
- affect the least number of bases
*
What type of mutation is the most rare? What is its impact on bases?
gain or loss of whole chromosomes is the most rare, but affects more bases
What is the impact of most mutations?
most of them are mildly bad
What do neutral mutations allow us to measure and why?
neutral mutations allow us to measure genetic dift, genetic gene flow, etc. They do not have an effect on processes
What type of variation is closely tied to neutral mutations?
segregating variation
What does recombination during meiosis do?
generates variation
What does independent assortment ensure?
novel combinations of alleles
Where does recombination on the chromosome occur?
occurs in random places on the chromosome
What does most of the genetic variability in a population result from?
sexual reproduction, in any given generation input from mutation very small
How can evolution be defined?
a change in allele frequencies over time
What is the function and importance of population genetics?
- tracks the fate, across generations, of alleles in populations
- population geneics is concerned with whether a particular allele or genotype will become more or less common over time, and why
