Relaxed molecular clock dating

Genetic sequence data provide information about the distances between species or branch lengths in a phylogeny, but not about the absolute divergence times or the evolutionary rates directly.Bayesian methods for dating species divergences estimate times and rates by assigning priors on them.

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The genetic equidistance phenomenon was first noted in 1963 by E.Later Allan Wilson and Vincent Sarich built upon this work and the work of Motoo Kimura observed and formalized that rare spontaneous errors in DNA replication cause the mutations that drive molecular evolution, and that the accumulation of evolutionarily "neutral" differences between two sequences could be used to measure time, if the error rate of DNA replication could be calibrated.Originally, it was assumed that the DNA replication error rate was constant – not just over time, but across all species and every part of a genome that you might want to compare.Margoliash, who wrote: "It appears that the number of residue differences between cytochrome C of any two species is mostly conditioned by the time elapsed since the lines of evolution leading to these two species originally diverged.The molecular clock (based on the molecular clock hypothesis (MCH)) is a technique in genetics to date when two species diverged.The molecular clock is a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged.The biomolecular data used for such calculations are usually nucleotide sequences for DNA or amino acid sequences for proteins.Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social | Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology | Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline) The molecular clock (based on the molecular clock hypothesis (MCH)) is a technique in genetics, which researchers use to date when two species diverged.It deduces elapsed time from the number of minor differences between their DNA sequences. The notion of a "molecular clock" was first attributed to Emile Zuckerkandl and Linus Pauling who, in 1962, noticed that the quantity of amino acid differences in hemoglobin between lineages roughly matched the known evolutionary rate of divergence based upon fossil evidence.They generalized this observation to assert that the rate of evolutionary change of any specified protein was approximately constant over time and over different lineages (based on the molecular clock hypothesis (MCH)).The genetic equidistance phenomenon was first noted in 1963 by Emanuel Margoliash, who wrote: "It appears that the number of residue differences between cytochrome c of any two species is mostly conditioned by the time elapsed since the lines of evolution leading to these two species originally diverged.