Lecture 21: Speciation Flashcards
Species concept based on Physical Traits/Characteristics
Morphological
Species concept based on breeding and producing viable offspring
Biological
Species concept based on how individuals interact with their environment
Ecological Species Concept
Define Habitat Isolation
Species do not cross paths or interact with each other
Define Temporal Isolation
Species mate at different times
Define Behavioral Isolation
Species are not drawn to another species aura
Species attempt to mate but are not morphologically compatible
Mechanical Isolation
Gametic Isolation
Species mate but their gametes are not compatible
What are 5 Pre-Zygotic mechanisms?
1.) Habitat Isolation
2.) Temproal Isolation
3.) BEhavioral ISolation
4.) Mechanical ISolation
5.) Gametic ISolation
Reduced Hybrid Viability
HYbrid offspring dies early
Reduced Hybrid Fertility
Hybrid are born but cannot reproduce
Hybrid Breakdown
Offspring of Hybrids are cooked
3 Post Zygotic MEchanisms?
1.) Reduced Hybrid Viability
2.) Reduced Hybrid Fertility
3.) Hybrid BReakdown
What are 2 mechanisms of Speciation?
- Allopatric
- Sympatric
Species diverge due to geographical barrier
Allopatric speciation
Species diverge despite there not being a geographical barrier
Sympatric Speciation
Examples of Sympatric speciation mechanisms
Polyploidy, Sexual Selection, Niche Partitioning (Habitat differentiation)
What is the difference between Phylogeny and Taxonomy?
-Phylogeny shows the evolutionary history
- Taxonomy refers to the naming/ categorization of organisms (ex. Bi(2) - nomial (name) nomenclature)
Phylogeny based on Taxonomy is known as
Cladistics
Define Polytomy
Shows unclear evolutionary relationship (3 or more branches)
No common ancestor
Polyphyletic
Common ancestor + ALL descendants
Monophyletic/Clade
Common Ancestor + Excludes some descendants
Paraphyletic
