Microdiversity

Microdiversity refers to the small-scale genetic and phenotypic variation among individuals within a single population or species. In microbiology, it describes the genetic heterogeneity that can exist among cells or strains sharing the same habitat, and it is distinct from macrodiversity, which compares diversity across species or higher taxonomic levels.

Variation arises from mutation, recombination, and horizontal gene transfer, and is shaped by selection, genetic drift, and ecological microhabitats. Microdiversity can manifest as single-nucleotide polymorphisms, gene content differences, regulatory changes, or copy number variation, leading to subtle but meaningful differences in metabolism, stress response, growth rate, or ecological niche.

Ecologically, microdiversity contributes to resilience and functional stability of communities. It enables rapid adaptation to environmental fluctuations, supports niche partitioning within a habitat, and can maintain ecosystem processes when conditions change. In microbes, microdiverse lineages may occupy distinct micro-niches or exhibit different strategies for resource use or tolerance to stress, helping the population persist under variable conditions.

Measurement and analysis rely on sequencing-based methods. Metagenomics, single-cell genomics, and high-resolution amplicon sequencing reveal intra-population diversity, while metrics such as nucleotide diversity (pi), allelic richness, and intraspecific haplotype structure quantify microdiversity. Interpretation often requires distinguishing true biological variation from sequencing artifacts and considering spatial and temporal scales.

Applications of microdiversity research include understanding microbial ecology, tracking adaptation to environmental change, and informing strategies for managing ecosystems or industrial microbiology processes.