Spatially explicit analyses highlight idiosyncrasies: species extinctions and the loss of evolutionary history
Scenarios of species extinction have been created to assess how the loss of species affects the loss of evolutionary history (EH). However, estimates of the rate of EH loss at regional scales are scarce. Here we provide the first estimate of projected EH loss of New World anurans encompassing both continental and regional scales.
We implemented two distinct extinction scenarios to investigate variations in rates of EH loss, contrasted through a suboptimality index. The analytical procedure was carried out on a continental scale, comprising all 3017 New World anuran species, and on a regional scale, for each of the 3858 cells of the grid, according to the species assemblage within each cell.
About 64% of the EH of the New World anurans would still exist even if half of the New World anurans go extinct, regardless of whether extinction is random or threatened species go extinct first. The extinction of all 951 threatened anuran species in the New World, or the same number of species chosen randomly from the 3017 total, would cause similar loss of EH. However, spatially explicit analyses that account for idiosyncrasies in the phylogenetic structure and threat status of each regional assemblage show that EH loss caused by extinction of threatened species is uneven across the continent.
Conservation strategies that aim to mitigate pressures on EH loss must be designed with a focus on regional spatial scales, in order to embody the phylogenetic structure and threat status of species that are particular to each assemblage.