Bio 345 Evolution FINAL EXAM SET
Biological Species Concept (BSC): -
Species are groups of actually or potentially interbreeding natural populations that are โ๏ธ๎
reproductively isolated from other such groups (Mayr, 1942)
If the species can mate and have fertile offspring
Phylogenetic Species Concept (PSC): -
A phylogenetic species is an irreducible cluster of organisms diagnosably different from โ๏ธ๎
other such clusters, and within which there is a parental pattern of ancestry and descent (Cracraft,
1989).
Introgression: -
Gene exchange across distantly related speciesโ๏ธ๎
(Horizontal Gene Transfer)
Introgression: -
The movement, the incorporation, of genes from one genetically distinct population โ๏ธ๎
(usually considered a species) into another.
Geographic isolation: -
Reduction or prevention of gene flow between populations by an extrinsic barrier to โ๏ธ๎
movement, such as topographic features or unfavorable habitat.
Reproductive isolation: -
Reduction or prevention of gene flow between populations by genetically determined โ๏ธ๎
differences between them.
Allopatric populations: -
Populations occupying separated geographic areas.โ๏ธ๎
Parapatric populations: -
Populations occupying adjacent geographic areas, meeting at the border.โ๏ธ๎
Sympatric populations -
Populations occupying the same geographic area and capable of encountering each other.โ๏ธ๎
Hybrid zone: -
A region where genetically distinct populations meet and interbreed to some extent, โ๏ธ๎
resulting in some individuals of mixed ancestry (i.e., hybrids).
Sister species: -
two species descended from single ancestral speciesโ๏ธ๎
Distinguished by chromosome rearrangements: inversions and reciprocal translocations (especially)
lead to reduced hybrid fertility
Premating barriers: -
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