Atavism is the tendency of reversion. Atavism means a throw back. Atavism is a tendency to reproduce ancestral type in plants and in animals. Atavism is the tendency to resemble one's grandparents or great-grandparents more than parents. Atavism is also seen as evidence of evolution. 'Atavism' is people in the modern era reverting to the ways of thinking and acting of a former time. The word atavism is derived from the Latin atavus, which means an ancestor. This concept of atavism was used by Cesare Lombroso (1835-1909) to describe a type of criminal he called the born criminal.
Atavistic criminal was one representing an earlier stage of human evolution. This ancestral type of atavism was identified by Lombroso through several stigmata or physical characteristics like the length of ear lobes and fingers, and also the bone structure of the head. Atavism is a modification of a biological structure whereby an ancestral trait reappears after having been lost through evolutionary change in previous generations. Atavism occurs when genes for previously existing phenotypic features are preserved in DNA, and these become expressed through a mutation that either knocks out the overriding genes for the new traits or makes the old traits override the new one.
Atavism denotes the tendency to revert to ancestral type. Atavism is an evolutionary throwback, traits reappearing which had disappeared generations ago. Atavisms occur because genes for previously existing phenotypical features are often preserved in DNA, though the genes are not expressed in some or most of the organisms possessing them.
Atavism is generally understood as a biological phenomenon which brings to sight a recurrent phenotypic character which was lost for extinct generations. Hallux valgus cannot be considered as an atavism because clinical history and findings do not correspond to the archaic prehensile foot and its evolution.
Ethno-nationalism in process:
ethnicity, atavism and indigenism in Riau, Indonesia - Author: Wee V.
Abstract: This paper briefly highlights Riau accounts of the struggle for independence (1945-65), shows how atavism and indigenism have been symbolically and ritually realized on the ground (1965-97) and examines some key developments in Riau after the fall of Suharto (1997-2001).
Atavisms: medical, genetic, and evolutionary implications - Tomic N, Meyer-Rochow VB. Abstract: Traits expected to be lost in the evolutionary history of a species occasionally reappear out of the blue. Such traits as extra nipples or tails in humans, hind limbs in whales, teeth in birds, or wings in wingless stick insects remind us that certain genetic information is not completely lost, but can be reactivated. Atavisms seem to violate one of the central evolutionary principles, known as Dollo's law, that "an organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors."
Although it is still not clear what triggers and controls the reactivation of dormant traits, atavisms are a challenge to evolutionary biologists and geneticists. This article presents some of the more striking examples of atavisms, discusses some of the currently controversial issues like human quadrupedalism, and reviews the progress made in explaining some of the mechanisms that can lead to atavistic features.