Preservatiebias

Preservatiebias, often translated as preservation bias in English, is a systematic distortion in the record of past life or information caused by differential preservation of material. In paleontology it arises from taphonomic processes that affect which organisms become fossilized and which do not, leading to a fossil record that over- or under-represents certain taxa, environments, or time intervals. In archival contexts, it can refer to biases introduced by what survives selection processes, storage, or media decay.

Key drivers include the durability of tissues, skeletonization, mineralization, depositional settings (marshes, anoxic basins, sandstone versus clay), post-depositional alteration, and sampling intensity. Hard-bodied organisms fossilize more readily than soft-bodied ones; fine-grained sediments preserve delicate features; arid or cold conditions favor preservation; scavenging and decay reduce recoverability. Geographic and temporal gaps reflect rock availability and research history as well as access.

Impact includes biases in measured diversity, morphology, and ecology; misinterpretations of community structure; and confounding signals in macroevolutionary studies. Examples are the underrepresentation of soft tissues, small-bodied organisms, or taxa from tropical environments, and the overrepresentation of rapidly accumulating, heavily skeletonized taxa or Lagerstätten.

Mitigation involves taphonomic analysis to understand biases, standardization of sampling, and the use of multiple proxies (trace fossils, isotopes, microfossils), along with statistical correction methods and modeling to account for preservation likelihood. Cross-validation with contemporary analogs and experimental taphonomy, together with explicit uncertainty assessments, helps contextualize inferences drawn from biased records.