The Breakdown of Static and Evolutionary Allometries during Climatic Upheaval.

The Breakdown of Static and Evolutionary Allometries during Climatic Upheaval. Am Nat. 2017 Sep;190(3):350-362 Authors: Brombacher A, Wilson PA, Bailey I, Ezard THG Abstract The influence of within-species variation and covariation on evolutionary patterns is well established for generational and macroevolutionary processes, most prominently through genetic lines of least resistance. However, it is not known whether intraspecific phenotypic variation also directs microevolutionary trajectories into the long term when a species is subject to varying environmental conditions. Here we present a continuous, high-resolution bivariate record of size and shape changes among 12,633 individual planktonic foraminifera of a surviving and an extinct-going species over 500,000 years. Our study interval spans the late Pliocene to earliest Pleistocene intensification of northern hemisphere glaciation, an interval of profound climate upheaval that can be divided into three phases of increasing glacial intensity. Within each of these three Plio-Pleistocene climate phases, the within-population allometries predict evolutionary change from one time step to the next and that the within-phase among-population (i.e., evolutionary) allometries match their corresponding static (within-population) allometries. However, the evolutionary allometry across the three climate phases deviates significantly from the static and phase-specific evolutionary allometries...
Source: The American Naturalist - Category: Biology Authors: Tags: Am Nat Source Type: research