In biology, atavistic traits can manifest as physical features, anatomical structures, or behavioral patterns that resemble those of ancient ancestors, even though these traits have been suppressed or lost in intervening generations. These atavisms provide glimpses into the evolutionary past of a species and can shed light on the process of trait evolution.
Atavistic traits can arise due to various factors, such as genetic mutations or the activation of dormant genes that have been preserved in the genome. They can offer insights into the genetic diversity and evolutionary relationships within a species or group of organisms, helping researchers understand the history of trait development and the preservation of ancestral features over time.
Examples of atavistic traits include the appearance of extra nipples or the presence of a tail-like structure in humans, vestigial hindlimbs in whales and dolphins, and the development of stripes or spots in certain horse breeds that resemble the coat patterns of their wild ancestors.
In a broader sense, the term "atavistic" can also be used figuratively to describe characteristics, beliefs, or behaviors considered outdated, primitive, or belonging to a past era.