In this paper, the main aspects to consider from a evolutionay genetic point of view in gene conservation are summarised. Most traits of adaptive significance are quantitative which means that no distinctive classes are segregating in the progeny. These traits are regulated by many genes, most of them have a small and identical effect on the trait, and one gene may be substituted by another resulting in the same effect. Therefore, there is no need to conserve rare genes in gene conservation. Presence of additive variance for a trait is a prerequisite for change via natural selection. Evolution is change of genetic set-up of a population. Natural selection, genetic drift, and mutations cause evolution while gene flow and phenotypic plasticity are constraints to it. All of them may act simultaneously, leading to a very dynamic situation. The continued existence of rare genes (< 1 % in a population), is dependent on chance events whether the gene contributes to fitness or not. The present genetic set-up is one out of many possible and it is transient. Therefore, it should not be the target in a dynamic gene conservation. A random selection of 500 trees in a population capture almost all genetic variation of importance for natural selection. It is important to distinguish between what is useful for a population for natural regeneration (Darwinian fitness) and what is demanded for production of human utilities (domestic fitness). Gene resource populations and breeding populations need a large additive variance. Production populations only need the amount of genetic variation that is satisfactory for production of the utilities demanded.