Macro Evolution Flashcards
Macroevolution
Evolutionary change in large groups of organisms over very large periods of time.
Speciation
Formation of a new species.
Biological Species Concept
groups of organisms who can breed and produce viable fertile offspring.
Morphological species concept
Species defined by body shape and or structures.
Ecological Species Concept
how members of species interact within their own niche.
Phylogenetic species concept
smallest group of individuals that share the same branch of a phylogenetic tree and share a common ancestor.
Reproductive isolation BSC
formation of new species can occur. If individuals cannot breed and produce viable offspring they are a different species.
Prezygotic Barriers
prefertilization barriers that prevent fertilization
postzygotic barriers
barriers that occur after fertilization that prevent viable offspring from being created.
ex of prezygotic barriers - no chance to mate
- geographic isolation
- temporal isolation
- behavioral isolation
More prezygotic barriers
- mechanical isolation - mating unsuccessful due to morphological differences
- gamete isolation - no fertilization
What is adaptive radiation?
formation of new species by movement into newly created niches
-many species result from one lineage
galapagos finches
allopatric speciation
results from geographic isolation that prevents gene flow.
What is gene flow?
Movement of individuals into and out of populations results in flow of genes between populations.
sympatric speciation
same geographic location speciation occurs
