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Updated: Feb 24, 2026
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Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
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Extended genomes: symbiosis and evolution.
1Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
Interface Focus
|August 26, 2017
Summary
The holobiont, an individual and its microbes, is rarely a unit of selection. Microbial heredity, or vertical transmission (VT), is key; without it, microbial evolution prioritizes microbe survival over host reproduction.
Area of Science:
- Microbial Ecology
- Evolutionary Biology
- Genetics
Background:
- An individual's biology is shaped by symbiotic microbes, influencing host ecology and evolution.
- The holobiont concept views an individual as a composite of host and symbionts, proposing it as a unit of selection.
Purpose of the Study:
- Critically examine the utility of the holobiont as a unit of selection.
- Investigate the role of microbial heredity in holobiont selection dynamics.
Main Methods:
- Literature review and critical analysis of the holobiont concept.
- Examination of microbial heredity, specifically vertical transmission (VT).
- Analysis of selection pressures on microbes within polymicrobial communities.
Main Results:
- Microbial heredity (VT) is crucial for the holobiont to function as a unit of selection.
- Direct VT allows microbial dynamics to be modeled with population genetics, distinct from nuclear gene models.
- Without VT, microbial fitness correlates with host survival, not reproduction, and is influenced by inter-microbial competition and host immunity.
Conclusions:
- The holobiont is generally not a useful unit of selection due to complex microbial selection pressures.
- Non-heritable microbes significantly impact organismal function, making their evolution a vital research area.
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