Genetic variation is described from the perspective of an individual. All the different levels of genetic information and variation are covered, ranging from whether an organism is unmixed or hybrid, has variations in genome, chromosomes and more locally in DNA regions, epigenetic variants or alterations in selfish genetic elements. Genetic constitution and heterogeneity of microbiota are highly relevant for health and wellbeing of an individual. Mutation rates vary widely for variation types e.g. due to sequence context. Genetic information guides numerous aspects in organisms. Types of inheritance, whether Mendelian or non-Mendelian, zygosity, sexual reproduction and sex determination are covered. Functions of DNA and functional effects of variations are introduced, along with mechanism that reduce and modulate functional effects, including TARAR countermeasures and intraindividual genetic conflict. TARAR countermeasures for tolerance, avoidance, repair, attenuation and resistance are essential for life, integrity of genetic information and gene expression. The genetic composition, effects of variations and their expression are considered also in diseases and personalized medicine. The text synthesizes knowledge and insight on individual genetic heterogeneity and organizes and systematizes the central concepts.

Computational modelling tools are widely used, however, articles describing modelling studies frequently do not contain sufficient details to allow the reader to comprehend the modelling procedure, quality of the produced model and validity of interpretations and predictions made based on the model. Here, guidelines were developed for items that have to be included when reporting studies and results based on protein modelling. A brief and concise checklist of required data items was compiled. These guidelines are simple to follow and apply, but require meticulous description of details, many of which can be placed to supplementary material. Authors have to pay attention to details when reporting modelling process. The generated structural models should be made publicly available, preferably by submitting to one of the existing repositories.