Contemporary Taxa Research Articles

The reconstructed evolutionary process.

Phylogenies reconstructed from contemporary taxa do not contain information about lineages that have gone extinct. We derive probability models for such phylogenies, allowing real data to be compared with specified null models of evolution, and lineage birth and death rates to be estimated.

Taxonomic Survivorship Curves

Taxonomic survivorship curves were derived from ecological and biomedical techniques for examining population structure and demographic trends. In simplest form, survivorship curves are graphical representations of the numbers or proportions of taxa that survive specific lengths of time. These curves provide a basis for calculating longevity, extinction rates, and other “life history” attributes of higher taxa. Survivorship curves have also been fruitful for comparative studies of contemporaneous higher taxa (e.g., cohorts), or among higher taxa that existed at different periods of geologic time. Various modifications of the concepts, both theoretical and methodological, have changed the way these curves are used to analyze paleontologic data.