BayCEER Workshop 2016

What is the main driver of global endemism patterns – isolation or climatic velocity?

Introduction

Current knowledge about species at remote islands and high mountain summits gives us strong hints that their isolated location is responsible for the local high rate of endemism. However, even the climatic velocity is influencing local speciation processes. How do both drivers influence endemism and how do they interact?

Material and Methods

Derived from island biogeography, global isolation patterns can be calculated with nearest distances to locations of similar ecological conditions. Therefore, a global isolation map based on distances to areas of similar elevations has been calculated. In literature, endemism is normally related to a given geographic region. However, for global analyzes a more general approach should be used: the rate of endemism of a given area can be calculated by overlapping species-specific maps of rarity (percentage of global occurrence).

Assumptions and open questions

We assume that isolation plays a major role since oceanic islands contain high rated of endemic species in face of their young geologic age. However, climatic velocity has been shown as a driver of speciation. Furthermore, we have to handle different (interacting) effects at different scales, e.g. functional species groups will show a different scale-dependency of endemism due to different body sizes, home ranges and migration behaviors.