Tip dating is a technique used in molecular dating that allows the inference of time-calibrated

phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

s. Its defining feature is that it uses the ages of the samples to provide time information for the analysis, in contrast with traditional '

node dating In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines, ...

' methods that require age constraints to be applied to the internal nodes of the evolutionary tree. In tip dating, morphological data and molecular data are typically analysed together to estimate the evolutionary relationships (

tree topology A tree topology, or star-bus topology, is a hybrid network topology in which star networks are interconnected via bus networks. Tree networks are hierarchical, and each node In general, a node is a localized swelling (a "knot") or a point of i ...

) and the divergence times among lineages (node times); this approach is also known as 'total-evidence dating'. However, tip dating can also be used to analyse data sets that only comprise morphological characters or that only comprise molecular characters (e.g., data sets that include samples of ancient DNA or of serially sampled

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

es). Tip dating has been implemented in Bayesian phylogenetic software and typically draws on the fossilised birth-death model for evolution. This is a model of diversification that allows

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...

, extinction, and sampling of

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

and

extant taxa Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, ''recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members st ...

. This promising method is not yet fully mature, and there are a number of possible biases or undesirable behaviour that must be taken into account when interpreting its results.

References

{{DEFAULTSORT:Tip dating Phylogenetics