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Fungi can be found in almost any environment, and play important roles in ecosystem processes such as nutrient cycling and degradation. Despite their importance, the vast majority of fungi have not yet been isolated and identified. Due to the difficulties inherent in culture-based methods, fungal ecologists have turned to community fingerprinting techniques, which utilise signal molecules to profile the fungal members of an environmental sample without culturing. Commonly used signal molecules include chitin, ergosterol, membrane lipids, and nucleic acids. Several DNA-based fingerprinting methods have been successfully applied to fungal communities, including D/TGGE (denaturing/temperature gradient gel electrophoresis), SSCP (single-stranded conformational polymorphism), RISA (ribosomal intergenic spacer analysis), and T-RFLP (terminal restriction length fragment polymorphism). These techniques allow the fungal ecologist to rapidly profile fungal populations in an ecosystem, without the need for laborious culturing or cloning.

DNA damaging agents are ubiquitous in the fungal environment with electromagnetic radiation and chemical mutagens adding to the mutation load caused by DNA replication errors. Fungi have evolved two broad adaptive strategies to cope with such genetic damage. Avoidance strategies include the development of pigments to act as radiation shields and the production of enzymes that degrade chemical mutagens. DNA repair strategies employ enzymes to directly restore the damaged DNA molecule to its original, wild-type condition. The study of yeast mutants that are defective in one of these DNA repair functions has let to a better understanding of an inherited predisposition to colon cancer in humans.