title: Fossils, phylogenies, and the challenge of preserving evolutionary history in the face of anthropogenic extinctions.
abstract: Anthropogenic impacts are endangering many long-lived species and lineages, possibly leading to a disproportionate loss of existing evolutionary history (EH) in the future. However, surprisingly little is known about the loss of EH during major extinctions in the geological past, and thus we do not know whether human impacts are pruning the tree of life in a manner that is unique in the history of life. A major impediment to comparing the loss of EH during past and current extinctions is the conceptual difference in how ages are estimated from paleontological data versus molecular phylogenies. In the former case the age of a taxon is its entire stratigraphic range, regardless of how many daughter taxa it may have produced; for the latter it is the time to the most recent common ancestor shared with another extant taxon. To explore this issue, we use simulations to understand how the loss of EH is manifested in the two data types. We also present empirical analyses of the marine bivalve clade Pectinidae (scallops) during a major Plio-Pleistocene extinction in California that involved a preferential loss of younger species. Overall, our results show that the conceptual difference in how ages are estimated from the stratigraphic record versus molecular phylogenies does not preclude comparisons of age selectivities of past and present extinctions. Such comparisons not only provide fundamental insights into the nature of the extinction process but should also help improve evolutionarily informed models of conservation prioritization.
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242;
authors.forename: Danwei
authors.initials: D
authors.lastname: Huang
authors.affiliation: Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN 55108; and.
authors.forename: Emma E
authors.initials: EE
authors.lastname: Goldberg
authors.affiliation: Section of Ecology, Behavior and Evolution, University of California, San Diego, La Jolla, CA 92093 kroy@ucsd.edu.
authors.forename: Kaustuv
authors.initials: K
authors.lastname: Roy
mesh_terms: D003198:Computer Simulation; D053476:Extinction, Biological; D005580:Fossils; D006802:Human Activities; D006801:Humans; D010802:Phylogeny; D013997:Time Factors
keywords: bivalves; extinction; fossil record; phylogenetic diversity; phylogeny