"Our study provides insight into how these threats may collectively influence the extinction risk of whole clades, consistent with the supposition that related species, with similar traits, share an intrinsic vulnerability to common kinds of threat." 

"Our study demonstrates strong clumping of extinction threat

within the amphibian phylogeny, suggesting that some entire

clades are especially extinction prone due to shared evolutionary

history."

From Corey, White - 2008 "Phylogenetic autocorrelation of extinction

threat in globally imperiled amphibians".