Week 2 Genetic Dridt Flashcards
What is natural selection?
→ considered the main evolutionary mechanism
→depends on genetic drift and gene flow
What is sampling error?
Random bias that occurs when sample sizes are small
What is the definition of a species?
Group of populations who’s members have the same
Potential to interbreed in nature to make fertile offspring
→ there are many definitions
→humans commonly identify organisms based on how they look
Reproductive isolation
Pre-zygotic and post-zygotic isolation
Define pre-zygotic mechanisms
Preventing the formation of a zygote
Define post-zygotic isolation
Impairing survival or reproduction of the zygote
What are the three phases of speciation
- Separation
- divergence
3.reproductive isolation
What is separation
Gene pools that separate into smaller groups that are isolated from gene flow
Define divergence
Groups of species diverging
What is allopathic speciation?
Closely related species have geological or physical separation
How does sexual selection drive reproductive isolation
→sexual selection involves rapid evolutionary changes
Define polyploidy
Genetic change causing instant reproductive isolation between gene pools
Define cline
Change in allele frequency across hybrid zone
→ provides evidence of substantial genetic exchange
What are the outcomes of hybridization?
- Hybrid zones are stable
- Reinforcement for reproduction
What is speciation?
Evolutionary process in which one species splits into 2 or more
→ Darwin realized that it explains why organisms share traits
Define microevolution
Changes over time in allele frequencies
Define macroevolution
Broad pattern of evolution above species level
What is the biological species concept
Species are groups of populations in which members can reproduce
How do prezogtic barriers block fertilization?
- Impeding members of a diff species
- Prevent successful mating
- Hindering fertilization
What is the morphological species concept
Characterizes a species in terms of body shape/other structure
What is the ecological species concept
Views species in terms of ecological niche, sum of how members of the species interact with the non-living parts of their environment
What is an allopolyploid?
Bertie when mating with each other but cannot interbreed
What is a hybrid zone?
Place where members of different species meet and mate
What are the main stages of life?
1.abiotic (non-living)
2. Small molecules
3. Packing into proto-cells
4. Origin of self replicating molecules
What is radio metric dating?
Method for determine age based on half-life of radioactive isotopes
What are the eons?
- Archaeon
- Proterozoic
- Phanerozoic
What are the eras?
- Paleozoic
- Mesozoic
- Cenozoic
Define stromatolites
Layers rocks that formed when prokaryotes bind thin films together
What does serial endosymbiosis mean?
Hypothesis predicts that mitochondria evolved before plastids through endusymbiotic events
What is adaptive radiation
Period of evolutionary change in which groups of organisms form new species with successful adaptations
What is heterochrony?
Evolutionary change in the timing or rate of an organisms development
Define paedomorphosis
Retention in an adult organism of juvenile features of its evolutionary ancestors
