Deciphering whale origins with molecules and fossils

Recent efforts by paleontologists to find fossils that record the origin of whales have yielded an impressive collection of transitional forms from the Eocene. Simultaneously, molecular biologists have dramatically increased the genetic information relevant to whale phylogeny. Combined analyses of the available data indicate areas of congruence but also gross conflict between characters from extinct and extant organisms. The incongruence underscores key areas where data have yet to be collected or merged in a combined phylogenetic framework. Continued synthesis of molecular and paleontological evidence is the strongest test of phylogenetic hypotheses, and provides a solid foundation for scenarios of adaptation related to this remarkable macroevolutionary transformation.