holobiont and hologenome

Compiled with AI assistance and selectively reviewed. Please consult the cited passages; the books remain the authoritative source. About this companion

Editorial synthesis · provisional

Definition

A holobiont is a host together with its associated microbial community; the hologenome names their combined genetic information. RB1 distinguishes this biological association from the stronger proposal that it acts as a unit of selection. Partner fidelity can matter to that proposal, while other accounts treat many associations as ecological communities. Microbial effects on host development or fitness alone do not establish collective evolutionary individuality.

Explanation

The source records host–microbiome effects on fitness, development and mating, with regulatory cross-talk among the reported interactions. Zilber-Rosenberg and Rosenberg supply the named hologenome proposal. The combined-information definition should remain separate from the claim that the association has a unified evolutionary fate.

The competing interpretation is explicit: under some conditions holobionts may be selection units, but many associations may be better understood as ecological communities. The native note preserves Bordenstein and Theis alongside Moran and Sloan rather than presenting one side as settled consensus. Selection can continue on hosts and microbes individually even in the collective model.

RB2’s endosymbiotic incorporation example shows a historical higher-order integration, while its microbiome comparison concerns networked dependence. Those affinities cannot make every contemporary host–microbe relationship equivalent to the origin of a eukaryotic cell. The proposal preserves different degrees of integration and the conditions required for the stronger selection-unit claim.

Scope and attribution

Retain the contested collective-selection claim and the possibility of ecological-community interpretation.

RB1 — The Real Book, Volume I: The Possible Is Real

Host–microbiome association, combined genetic information and conditional selection-unit status remain distinct.

Occurrence locators: 150, 153.

RB2 — The Real Book, Volume II: Becoming Is Being

Endosymbiotic integration and continuing microbiome dependence provide distinct comparisons.

Occurrence locators: 201.

Background used in the editorial explanation

Named theories and mechanisms are distinguished from neighboring background, homonyms and the author’s own synthesis. Reproduced AI passages retain their separate voice.