Speciation and Phylogeny Flashcards
Evolution Processes
Natural
Genetic
Mutation
Barriers lead to
Speciation
Natural Selection
Shows phynotype’s more favored offspring
More Favored Offspring have
- More favorable characteristics
- Must vary in characteristics
4 types of natural selection
- Directional
- Stabilizing
- Disruptive
- Balanced
2 types of evolution
- Convergent
- Divergent
Convergent
evolve from different origins, similar traits but no common ancestry (sharks vs. dolphons)
Divergent
evolve in diverse directions from common point, most things
Directional
one more favored to survive than others
Stabilizing
middle/average range more favored to survive
Balanced
no change, all able to survive
Disruptive
both opposite phynotypes favored to survive
Gene flow
transfer of gene variation
Increased gene flow
new population
Speciation
- from single ancestry
- splitting event
- must form 2 distinct species
- adds branches to tree
Species
evolutionary independent
3 major species concepts
Biology
morphospecies
phylogenetic
Biology specie concept
- same species if they can breed
- result in reproductive isolation
- Prezygotic
- Postzygotic
Prezygotic
before fertilization, prevents mating
- Temp/timing
- Habitable
- Behavoral
- Gamietal
- Mechanical
Postzygotic
offspring do not survive or cannot reproduce
- hybrid viability
- hybrid sterility
Morphospecies
use different morphology to distinguish species
- group by looks
- sexual dymorphent
Phylogenetic
genetics
- from same ancestry
- each branch has diff genes
- smallest used but based on testable facts
Allopatry
2 species geologically separated
- can’t breed
- no gene flow
- Dispersal vs. Vicariance
Dispersal
chose to move and form new colony
- genetically isolated by each other
- geo iso = gene iso
Vicariance
physical splitting of habitat
