Predicting extinction risk in declining species

Abstract

What biological attributes predispose species to the risk of extinction? There are many hypotheses but so far there has been no systematic analysis for discriminating between them. Using complete phylogenies of contemporary carnivores and primates, we present, to our knowledge, the ¢rst comparative test showing that high trophic level, low population density, slow life history and, in particular, small geographical range size are all signi¢cantly and independently associated with a high extinction risk in declining species. These traits together explain nearly 50% of the total between-species variation in extinction risk. Much of the remaining variation can be accounted for by external anthropogenic factors that a¡ect species irrespective of their biology.

Reconsidering the Loss of Evolutionary History: How Does Non-random Extinction Prune the Tree-of-Life?

“…There does seem to be a general trend within some clades for threatened species to be overrepresented in speciespoor clades (e.g. in mammals, Purvis et al 2000b andbirds, Bennett andOwens 1997 ). In plants, patterns appear mixed.…”

Comparative methods for studying primate adaptation and allometry

“…5,15,[17][18][19]69,106,107 For example, Deaner and Nunn 80 used a method based on independent contrasts to test whether brain size is subject to evolutionary lag relative to body size, but found no support for this hypothesis as an explanation for residuals in brain-body size plots. Thus, phylogenetic approaches to comparative biology have the potential to offer important insights into biological anthropology.…”

Metapopulation Capacity Meets Evolutionary Distinctness: Spatial Fragmentation Complements Phylogenetic Rarity in Prioritization

“…Small distribution area and island endemicity were the most important predictors of mammal extinction risk found through literature survey (Purvis et al 2000 ). Because of such isolation, we would expect evolutionary history to refl ect the spatial fragmentation.…”

“…Yet, some island populations can "show greater persistence than mainland populations of the same species, notwithstanding their smaller range sizes" (Channell and Lomolino 2000 ), perhaps refl ecting the advantages of living in sheltered isolation. Another study found that island endemics are not relatively more threatened than continental ones, considering their distribution size, "suggesting that evolutionary isolation is not the reason for their vulnerability" (Purvis et al 2000 ). Perhaps unravelling isolation and evolutionary factors can lead to a greater understanding of the unique state that island animals seem to occupy.…”