Genealogies: Pedigrees and Phylogenies are Reticulating Networks Not Just Divergent Trees
2016 (English)In: Evolutionary biology, ISSN 0071-3260, E-ISSN 1934-2845, Vol. 43, no 4, 456-473 p.Article in journal (Refereed) Published
Pedigrees illustrate the genealogical relationships among individuals, and phylogenies do the same for groups of organisms (such as species, genera, etc.). Here, I provide a brief survey of current concepts and methods for calculating and displaying genealogical relationships. These relationships have long been recognized to be reticulating, rather than strictly divergent, and so both pedigrees and phylogenies are correctly treated as networks rather than trees. However, currently most pedigrees are instead presented as “family trees”, and most phylogenies are presented as phylogenetic trees. Nevertheless, the historical development of concepts shows that networks pre-dated trees in most fields of biology, including the study of pedigrees, biology theory, and biology practice, as well as in historical linguistics in the social sciences. Trees were actually introduced in order to provide a simpler conceptual model for historical relationships, since trees are a specific type of simple network. Computationally, trees and networks are a part of graph theory, consisting of nodes connected by edges. In this mathematical context they differ solely in the absence or presence of reticulation nodes, respectively. There are two types of graphs that can be called phylogenetic networks: (1) rooted evolutionary networks, and (2) unrooted affinity networks. There are quite a few computational methods for unrooted networks, which have two main roles in phylogenetics: (a) they act as a generic form of multivariate data display; and (b) they are used specifically to represent haplotype networks. Evolutionary networks are more difficult to infer and analyse, as there is no mathematical algorithm for reconstructing unique historical events. There is thus currently no coherent analytical framework for computing such networks.
Place, publisher, year, edition, pages
2016. Vol. 43, no 4, 456-473 p.
Network, Pedigree, Phylogeny, Haplotype network, Evolutionary network, Phylogenetic history
IdentifiersURN: urn:nbn:se:uu:diva-311524DOI: 10.1007/s11692-016-9376-5ISI: 000388946900003OAI: oai:DiVA.org:uu-311524DiVA: diva2:1060311