Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs a variety of fields including paleontology, ecology, climatology and biology.
Paleoecology emerged out of the field of paleontology in the 1950s, though paleontologists have conducted paleoecological studies since the creation of paleontology in the 1700s and 1800s. Combining the investigative approach of searching for fossils with the theoretical approach of Charles Darwin and Alexander von Humboldt, paleoecology began as paleontologists began examining both the ancient organisms they discovered and the reconstructed environments in which they lived. Visual depictions of past marine and terrestrial communities has been considered an early form of paleoecology.
Classic paleoecology uses data from fossils and subfossils to reconstruct the ecosystems of the past. It involves the study of fossil organisms and their associated remains (such as shells, teeth, pollen, and seeds), which can help in the interpretation of their life cycle, living interactions, natural environment, communities, and manner of death and burial. Such interpretations aid the reconstruction of past environments (i.e., paleoenvironments). Paleoecologists have studied the fossil record to try to clarify the relationship animals have to their environment, in part to help understand the current state of biodiversity. They have identified close links between vertebrate taxonomic and ecological diversity, that is, between the diversity of animals and the niches they occupy. Classical paleoecology is a primarily reductionist approach: scientists conduct detailed analysis of relatively small groups of organisms within shorter geologic timeframes.
Evolutionary paleoecology uses data from fossils and other evidence to examine how organisms and their environments change throughout time. Evolutionary paleoecologists take the holistic approach of looking at both organism and environmental change, accounting for physical and chemical changes in the atmosphere, lithosphere and hydrosphere across time. By studying patterns of evolution and extinction in the context of environmental change, evolutionary paleoecologists are able to examine concepts of vulnerability and resilience in species and environments.
Community paleoecology uses statistical analysis to examine the composition and distribution of groups of plants or animals. By quantifying how plants or animals are associated, community paleoecologists are able to investigate the structures of ancient communities of organisms. Advances in technology have helped propel the field, through the use of physical models and computer-based analysis.