define atavism.what is the significance of atavism in evolution ..??
Answers
Atavism derives via French from Latin atavus, meaning "ancestor." ... Atavism is a term rooted in evolutionary study, referring to instances when an organism possesses traits closer to a more remote ancestor, rather than its own parents.
An atavism is the phenomenon in which a phenotype trait reappears in an organism after a period of absence. An atavism refers to a trait that is not present in the immediate predecessors of an individual, although was existent in its ancestors.
This is possible due to the way genes behave throughout the evolutionary process. When phenotype traits are lost during the process of natural selection, the genetic information in the DNA that codes for them is not necessarily lost and instead may just be inactive. This means that the genes can be reactivated, even after lying dormant for many generations.
Atavism differ from vestigial structures. These are phenotype features present in all members of a species, which in the organism’s evolutionary past have been necessary for survival, but are no longer used or functional in modern individuals