# Pleistocene
**Domain:** Geologic Time / Human Evolution / Climate
**Doc Type:** Canonical Period Node
**Maturity:** Developed
## Definition
The **Pleistocene** is the geologic epoch from about 2.58 million to 11,700 years ago, characterized by repeated glacial cycles and major evolutionary and geographic change. The genus _Homo_ diversified during it, and modern humans emerged late in the epoch.
## Nexus Context
The La Brea Tar Pits preserve a dense late-Pleistocene record inside modern Los Angeles. [[articles/The Evolutionary Roots of Silicon Valley|The Evolutionary Roots of Silicon Valley]] begins there to establish a central method: landscapes retain historical state even when later systems cover it.
This is [[wiki/Technical Archaeology|Technical Archaeology]] at geological scale. Fossils, sediments and preserved ecosystems are evidence from which a vanished process is reconstructed. The analogy to digital continuity is methodological, not ontological: preserved traces can support reconstruction without proving the continuing presence of the original subject.
## Sources / Provenance
- International Commission on Stratigraphy, International Chronostratigraphic Chart: https://stratigraphy.org/chart
- La Brea Tar Pits research and collections: https://tarpits.org/research-collections
## See Also
[[wiki/Fossil Record|Fossil Record]], [[wiki/Paleontology|Paleontology]], [[wiki/Continuity Evidence vs Continuity|Continuity Evidence vs Continuity]]