Cope's Rule in a modular organism: Directional evolution without an overarching macroevolutionary trend.

ABSTRACT: Cope's Rule describes increasing body size in evolutionary lineages through geological time. This pattern has been documented in unitary organisms but does it also apply to module size in colonial organisms? We address this question using 1169 cheilostome bryozoans ranging through the entire 150 million years of their evolutionary history. The temporal pattern evident in cheilostomes as a whole shows no overall change in zooid (module) size. However, individual subclades show size increases: within a genus, younger species often have larger zooids than older species. Analyses of (paleo)latitudinal shifts show that this pattern cannot be explained by latitudinal effects (Bergmann's Rule) coupled with younger species occupying higher latitudes than older species (an "out of the tropics" hypo

SUBMITTER: Liow LH 

PROVIDER: S-EPMC6771556 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature