A depositional taphonomy model for sedimentary ancient DNA based on biotic profiles of contrasting sedimentation regimes

Abstract

Sedimentary ancient DNA (sedaDNA) has become an important tool in Quaternary Science, but still little is understood of its taphonomy and whether sedaDNA represents the local vicinity or originates from distant sources. Here we show key insights can be made about the origins of sedaDNA by integrating sedimentological and sedaDNA data into a sediment influx depositional model. We reconstruct contrasting taphonomic regimes of lacustrine, alluvial, terrestrial and permafrost systems. Lacustrine systems show signals of regional catchment sources of sedaDNA, while alluvial, terrestrial and permafrost systems show a greater influence of DNA from the immediate local environment. However, there is a prevalence of mixed ecosystem signals which may span a broad temporal timeframe if sediment reworking has occurred. The ability to distinguish between local and distal sources of sedaDNA is of major importance in the interpretation of taxonomic profiles to reconstruct palaeoenvironments.