Hennig-speciation-tree or "speciation triangle".
Gene-Tree, Species-Tree Roconciliation:
This figure shows an example of the history of three Rare Genomic Changes (RGC). The analysis of sequence data such as point mutations at few loci can be misleading because of homoplasy. Only synapomorphies permit the reconstruction of phylogenetic relationships of taxa such as "Darwinian species". For example, retroelement insertions in a specific genomic site are always synapomorphic after a subsequent mutation while the empty insertion site is always ancestral, i.e. plesiomorphic. Evolution can be directly observed based on the strictly oriented time arrow.
Explanation:
Homoplasy is a similarity that is not inherited from a common ancestor, but obtained independently in two lineages, either by convergence or by reversion.
T1 (time 1 in the past): population genetics: the informative characters are the polymorphic, not fixed alleles.
T2 (time 2 more recent): population genetics/phylogenetics: the informative characters are the polymorphic, fixed and not fixed RGC-alleles.
T3 (present time): phylogenetics: the informative characters are the polymorphic, fixed RGC-alleles.
References:
1. Dettai, A., and J. N. Volff. 2006. Morphological Characters from the Genome: SINE Insertion Polymorphism and Phylogenies, p. 45-75. In D.-H. Lankenau and J. N. Volff (ed.), Transposable Elements and Genome Dynamics, vol. 4. Springer, Heidelberg.
2.Hennig, W. 1965. Phylogenetic Systematics. Ann. Rev. Entomol. 10:97-116.
3.Hennig, W. 1982. Phylogenetische Systematik. Parey, Berlin Hamburg.
Hennig-speciation-tree or "speciation triangle".
Gene-Tree, Species-Tree Roconciliation:
This figure shows an example of the history of three Rare Genomic Changes (RGC). The analysis of sequence data such as point mutations at few loci can be misleading because of homoplasy. Only synapomorphies permit the reconstruction of phylogenetic relationships of taxa such as "Darwinian species". For example, retroelement insertions in a specific genomic site are always synapomorphic after a subsequent mutation while the empty insertion site is always ancestral, i.e. plesiomorphic. Evolution can be directly observed based on the strictly oriented time arrow.
Explanation:
Homoplasy is a similarity that is not inherited from a common ancestor, but obtained independently in two lineages, either by convergence or by reversion.
T1 (time 1 in the past): population genetics: the informative characters are the polymorphic, not fixed alleles.
T2 (time 2 more recent): population genetics/phylogenetics: the informative characters are the polymorphic, fixed and not fixed RGC-alleles.
T3 (present time): phylogenetics: the informative characters are the polymorphic, fixed RGC-alleles.
References:
1. Dettai, A., and J. N. Volff. 2006. Morphological Characters from the Genome: SINE Insertion Polymorphism and Phylogenies, p. 45-75. In D.-H. Lankenau and J. N. Volff (ed.), Transposable Elements and Genome Dynamics, vol. 4. Springer, Heidelberg.
2.Hennig, W. 1965. Phylogenetic Systematics. Ann. Rev. Entomol. 10:97-116.
3.Hennig, W. 1982. Phylogenetische Systematik. Parey, Berlin Hamburg.