Evolutionary Genetics
Evolution occurs within populations, but this process can lead to ‘splitting’ of
lineages through time – evolution as a ‘branching’ process. These ‘divergent’
populations can become species.
Biological Evolution: genetic (or phenotypic) changes in a group of
organisms
Anagenesis: evolution taking place in a single group (a lineage) with the
passage of time
Cladogenesis: splitting of one lineage into 2, new species arise.
Phenotypic species concept:
Biological species concept:
Phylogenetic species concept: species are ‘tips’ on a phylogeny –
they represent the smallest set of organisms that share a common ancestor and
can be distinguished from other such sets. So variation at the end of a branch on
a phylogeny would all be a single species.
Evolution occurs within populations, but this process can lead to ‘splitting’ of
lineages through time – evolution as a ‘branching’ process. These ‘divergent’
populations can become species.
Biological Evolution: genetic (or phenotypic) changes in a group of
organisms
Anagenesis: evolution taking place in a single group (a lineage) with the
passage of time
Cladogenesis: splitting of one lineage into 2, new species arise.
Phenotypic species concept:
Biological species concept:
Phylogenetic species concept: species are ‘tips’ on a phylogeny –
they represent the smallest set of organisms that share a common ancestor and
can be distinguished from other such sets. So variation at the end of a branch on
a phylogeny would all be a single species.
