Phenotypic variance inflation in fossil samples: an empirical assessment

摘要: Evolutionary change during the interval in which a fossil sample accumulates will inflate variance of that relative to population-level standing variation. If this effect is wide- spread and severe, paleontological samples not provide reliable estimates population var- iation. Although few published studies conducted test possibility have found similar levels variation differing greatly temporal acuity, paucity case pre- vents assessing generality pattern. In paper, two independent, literature-based ap- proaches are used expand data available address issue. The first approach compares morphometric variability Quaternary mammal with from related modern populations. second artificially lumps separate evolving lin- eages calculates effects analytical time-averaging. Both approaches yield consistent results indicating observed time-averaged typically only slightly inflated (approximately 5%) values. This finding suggests rates evolution slow when scaled within-population variation, providing support for stasis as dominant mode within-lineage evolution. An important practical con- sequence these findings generally show trait variances covariances parameters, has been an but im- plicit assumption many phenotypic