Paleoecology and Extinction
Paleoecology reconstructs ancient ecosystems and the patterns of diversification and extinction, including the great mass extinctions of Earth history.
Definition
Paleoecology is the study of the relationships of ancient organisms to one another and to their environments, while extinction studies analyze the loss of species and lineages through geological time.
Scope
This area covers the reconstruction of past communities and environments, the analysis of long-term diversity, origination, and extinction, the major mass extinction events and their recoveries, and the use of fossils to date and correlate strata in biostratigraphy.
Sub-topics
Core questions
- How are ancient communities and environments reconstructed?
- What patterns characterize diversity, origination, and extinction over time?
- What caused the major mass extinctions and how did life recover?
- How do fossils serve to date and correlate rock strata?
Key concepts
- Paleocommunity reconstruction
- Origination and extinction rates
- Mass extinction and recovery
- Biostratigraphic correlation
Key theories
- The big five mass extinctions
- Analysis of the marine fossil record identified several major mass extinctions, including the end-Permian and end-Cretaceous events, standing out above background extinction.
- Diversity dynamics through time
- Origination and extinction rates govern the rise and fall of clades and the overall diversity of life, analyzed through quantitative paleobiology.
Clinical relevance
Paleoecology and extinction studies provide the deep-time context for understanding modern biodiversity loss and ecosystem response to environmental change, and biostratigraphy underpins geological dating and resource exploration.
History
Quantitative analysis of the marine fossil record by Sepkoski and Raup in the late twentieth century established the modern study of diversity and mass extinction. Paleoecology grew alongside as a discipline integrating taphonomy, sedimentology, and community analysis.
Debates
- Periodicity and causes of mass extinctions
- Whether mass extinctions are periodic and whether they share common causes such as impacts or volcanism remains debated.
Key figures
- David M. Raup
- J. John Sepkoski Jr.
- Anthony Hallam
Related topics
Seminal works
- raup1982
- foote2007
Frequently asked questions
- What is paleoecology?
- Paleoecology is the study of how ancient organisms interacted with each other and their environments, reconstructed from fossils and the rocks that contain them.
- How many mass extinctions have there been?
- Analyses of the fossil record commonly recognize five major mass extinctions in the Phanerozoic, alongside many smaller extinction events.