higher mortality, stunted growth, delayed flowering, and lower fruit set, indicating that epigenes may increase fitness. Furthermore, environmentally induced epigenetic responses to stress have been shown to be inherited and positively correlated with fitness. In animals, communal nesting changes mouse behavior increasing parental care regimes and social abilities that are hypothesized to increase offspring survival and access to resources (such as food and mates), respectively. Inheritance of immunity In 2021, it was shown for the first time how immunity is inherited – via epigenetic changes – in mammals (mice). Macroevolutionary patterns Inherited epigenetic effects on phenotypes have been well documented in bacteria, protists, fungi, plants, nematodes, and fruit flies. Though no systematic study of epigenetic inheritance has been conducted (most focus on model organisms), there is preliminary evidence that this mode of inheritance is more important in plants than in animals. The early differentiation of animal germlines is likely to preclude epigenetic marking occurring later in development, while in plants and fungi somatic cells may be incorporated into the germ line. It is thought that transgenerational epigenetic inheritance can enable certain populations to readily adapt to variable environments. Though there are well documented cases of transgenerational epigenetic inheritance in certain populations, there are questions to whether this same form of adaptability is applicable to mammals. More specifically, it is questioned if it applies to humans. As of late, most of the experimental models utilizing mice and limited observations in humans have only found epigenetically inherited traits that are detrimental to the health of both organisms. These harmful traits range from increased risk of disease, such as cardiovascular disease, to premature death. However, this may be based on the premise of limited reporting bias because it is easier to detect negative experimental effects, opposed to positive experimental effects. Furthermore, considerable epigenetic reprogramming necessary for the evolutionary success of germlines and the initial phases of embryogenesis in mammals may be the potential cause limiting transgenerational inheritance of chromatin marks in mammals. Life history patterns may also contribute to the occurrence of epigenetic inheritance. Sessile organisms, those with low dispersal capability, and those with simple behavior may benefit most from conveying information to their offspring via epigenetic pathways. Geographic patterns may also emerge, where highly variable and highly conserved environments might host fewer species with important epigenetic inheritance. Controversies Humans have long recognized that traits of the parents are often seen in offspring.