Biomarker indicators of past ecosystems

Biomarkers are identifiable molecular fossils preserved in archaeological and geological archives, and are used to reconstruct Quaternary ecosystems, encompassing climate, environment, and biota. The diversity and resilience of biomarkers, in addition to their accessible and consistent laboratory analytical techniques, make them a powerful tool for paleoclimatologists, paleoecologists, and archaeologists. Here, we provide an overview of the main biomarker groups relevant to these fields, the general extraction methods for biomolecules, and the established and emerging biomarker compound distribution, index, and isotope proxies for atmospheric pCO₂, hydroclimate, temperature, vegetation, fire, primary productivity, and mammalian presence.