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Ring of life

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

The "ring of life" is a model that describes the evolutionary relationships among the three domains of life: Bacteria, Archaea, and Eukarya. It emphasizes horizontal gene transfer as a significant evolutionary mechanism, particularly in early life forms.

5 Must Know Facts For Your Next Test

  1. The ring of life model suggests that the last universal common ancestor (LUCA) had characteristics of both Bacteria and Archaea.
  2. Horizontal gene transfer plays a crucial role in the ring of life concept, contrasting with the traditional tree of life model.
  3. Eukaryotes are believed to have emerged through symbiotic relationships involving both bacterial and archaeal ancestors.
  4. The ring of life challenges the linear progression implied by phylogenetic trees, proposing a more network-like evolution.
  5. Genomic analyses support the idea that many eukaryotic genes have prokaryotic origins from both Bacteria and Archaea.

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