Chapter 1 - Evolution Flashcards
What are Hardy-Weinberg 5 assumptions?
- No mutation
- No immagration
- Random mating
- Large Population
- No selection taking place
What is evolution?
Change is gene frequency in a population over time
What 5 things need to happen for evolutionary change to take place?
- mutations (very important)
- gene flow
- non random mating
- small population
- Natural selection
Mutations
You don’t get new phenotypes without changes in DNA
Gene Flow
Flows like a river, is directional - new allele added into populations
Genetic Drift
ocean, random chance. two catagories
Founder effect
new pop. from old pop.
Bottlenecking
random chance, pop is reduced - favors no trait.
Natural Selection needs:
- pop with varied pheotype
- reproductive sucess in that phenotype
- must be heritable
Frequency-dependent selection
- directional favors one extreme
- stabilizing favors the norm
- disruptive favors both extremes
What % has that advantage?
Negative favors oddball
Limits of selection
Can favor one and reduce another; not enough variability to see much selection
Darwin’s subtheories - 5
- Perpetual change (always changing)
- Multipication of species (not a fixed number)
- gradualism (gradual change)
- common decent
- natural selection (survival of the fittest)
Fossil evidence in a large scale:
- Very rare - every one is translational species
- snapshot in a large picture
- some don’t fossilize well
Homolgous structure
related groups, unrelated functions ex. human arms and bat wing
Analagous structure
unrelated groups, similar function - dragonfly wings and bat wings
Vastigial structures
present but don’t serve a purpose
Covergent evolution
organisms unrealted look similar - different ways to make a mouse dark
Look up critisms to evolution
just a theory, intellegent design, etc.
Prezygotic
- Ecological - don’t come in contact
- Behavioral - different mating retuals
- Temperal - timing of reproduction is off
- Mechanical - lock and key
- Gametic
Sympactirc species
in contact with each other geographically
Allopatric
geographically isolated
Sympatric
- Instantaneously - abnormal number of choromosomes
2. long periods of time - extremes are favored
Adaptive radiation
species become two species then come back together
Character displacement
food source not in competition with other peeps
Systematics
evolutionary relationshhhhhips between animals
Taxonomy
classification of living things
Pylogony
see relatedness - family tree
Derived charactristics
characteristics in a group that don’t exist outside a group
Monophyletic group
common ansestor with all decendents in some group
Paraphyletic group
don’t have the whole group
Polyphyletic group
similar in some aspects, but not closely related
