All we need now is fossils; a new phylogenetic dating method (PATHd8) allowing thousands of taxa and multiple fossil constraints.

• Estimation of divergence times in phylogenetic trees using sequence databecomes increasingly popular, but so far dating studies have given widely different results,and especially datings of the lower nodes within the angiosperms and metazoans, have givenmuch older ages than those obtained from the fossil record. It has been concluded in differentstudies that more taxa, and more fossils are needed for more reliable age estimates. For thisreason, a dating method that can handle very large data sets with multiple fossil constraints isnecessary.Chronograms obtained by e.g. penalized likelihood and Bayesian methods, oftenadds a large "ghost range" to the fossil record, and produces chronograms with a more or lesssmooth appearance, even if the corresponding phylograms have apparently veryheterogeneous rates. Compared to the other methods, our recently developed method,PATHd8, gives the results with the best agreement with the fossil record, which coincideswith the least smooth appearance of the chronograms. When other programs often run intocomputational problems when analysing trees with hundreds of leaves, PATHd8 has noproblems analysing thousands of taxa instantaneously. An arbitrary number of fossil ageconstraints can be specified, either as fixed-, minimum or maximum age.With our new method, the biggest problem in dating studies is that we needmore fossils, and these fossils must be well dated and assigned to the correct branches of thephylogeny. Therefore, to accomplish divergence time estimates, which hopefully approximatethe real ages, biologists now need to cooperate with palaeontologists.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Biologisk systematik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biological Systematics (hsv//eng)

NATURVETENSKAP  -- Matematik -- Beräkningsmatematik (hsv//swe)

NATURAL SCIENCES  -- Mathematics -- Computational Mathematics (hsv//eng)

Nyckelord

divergence time

dating

PATHd8

phylogeny

fossil

Historical geology and palaeontology

Historisk geologi och paleontologi

Systematics and phylogenetics

Systematik och fylogeni

Applied mathematics

Tillämpad matematik

Publikations- och innehållstyp

ref (ämneskategori)

kon (ämneskategori)