Fingerprint homoplasy: Koalas and humans

Abstract

Fingerprints (dermatoglyphes) consist of patterns formed by parallel ridges on bare skin of fingertips. They are typical for higher primates, but occur sporadically in other mammals. We have recently observed the presence of dermatoglyphes, microscopically and macroscopically similar to those of humans, on the fingers and toes of the tree-climbing marsupial Phascolarctus cinereus. Presence of nearly identical dermatoglyphes in lineages of mammals undergoing separate evolution for at least 70 million years, but adapting to climbing and grasping, indicates that adaptive regularities may be a common feature of the evolutionary process.