Rapid Anthropocene speciation reveals pull of the recent: A response to Thomas

Abstract

Evolutionary biologists have long recognized that evidence of increased species diversification rates in recent versus fossil records may simply reflect better sampling of contemporary biodiversity, a bias they have termed the ‘Pull of the Recent’ [1,2]. Estimates of speciation in geological time necessarily incorporate both speciation and extinction, as only species that persisted long enough to leave fossil or genetic traces will be included. By contrast, estimates of recent speciation rates do not incorporate extinction because of the lag between speciation and extinction, thus inflating contemporary estimates of speciation relative to geological estimates. There are several reasons why the proposition of increased plant speciation rates as a result of human-driven hybridization in the Anthropocene [3] cannot be distinguished from a Pull-of-the-Recent artifact arising from greater sampling effort and ease of detection of contemporary hybrids.