ANT203H5 Lecture Notes - Lecture 4: Sympatric Speciation, Allopatric Speciation, Fiba Africa
2017-01-12
Phylogenetic Species Concept
- It separates species based on identifiable parent patterns
- Can be geno or phenotypic but usually used phenotypic characteristics
Speciation
- New species evolve too slowly to study in one lifetime- except bacteria and some insects
- New species evolve too quickly to study in the fossil record
- Species can occur by allopatric, parapatric or sympatric speciation
Allopatric speciation
- a physical barrier that prevents gene flow and once it separates there could be changes to the
species (slowly)
selection favours different phenotypes in these regions
- Likely what happened in Madagascar to lemurs
- Most common way of speciation
The physical barrier
- Isolates part of a population
- Disrupts gene flow
Parapatric speciation
- New species arise due to selection combined with partial genetic isolation
- Hybrids less fit, so select for behaviour and morphology that reduces gene flow
- Seen in some primates
- Limited amount of gene flow, limited enough that the two species diverge
- Happening in baboons and some lemur species
Sympatric speciation
- Might be happening in south Africa
- Selection for different phenotypes even when there is no geographic isolation
- Not as well supported
Species in the Fossil Record
- Cant use bio species concept
- Examine variations
- Paleospecies are hard to differentiate
- Lumpers vs splitters
Intraspecification- within the species
Interspecifications- between species
*************Helpful hints for remembering classification******
Superfam- eds i oidea
Family- ends in idea
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Document Summary
It separates species based on identifiable parent patterns. Can be geno or phenotypic but usually used phenotypic characteristics. New species evolve too slowly to study in one lifetime- except bacteria and some insects. New species evolve too quickly to study in the fossil record. Species can occur by allopatric, parapatric or sympatric speciation. A physical barrier that prevents gene flow and once it separates there could be changes to the species (slowly) selection favours different phenotypes in these regions. New species arise due to selection combined with partial genetic isolation. Hybrids less fit, so select for behaviour and morphology that reduces gene flow. Happening in baboons and some lemur species. Limited amount of gene flow, limited enough that the two species diverge. Selection for different phenotypes even when there is no geographic isolation. Other orders have arboreal species that do(cid:374)(cid:859)t share pri(cid:373)ate patter(cid:374), for exa(cid:373)ple racoons. The primate pattern represents an adaption to foraging or insects.
