Growth and obsolescence of literature in theoretical population genetics

Growth and aging (or obsolescence) are two topics which have attracted world-wide attention in the informetrics literature. Extensive reviews on obsolescence has been published by Gapen and Milner(1) and Line(2) in the past. Obsolescence is the phenomenon of "the reduced use or decline in the use of information ton a certain topic) with time". Here we have to clear whether the concern is with documents as such or with the information they contain representing knowledge. If the obsolescence of documents (decline in its use) with time is concerned, it is of practical interest in the probability that an item will be required as a guide to such questions as: (a) when to discard older volumes, (b) how long to keep new ones, (c) what sort of retrospective storage and access in information retrieval system should provide, and so on. It the concern is with knowledge, obsolescence may be defined as a decline over time in the validity or utility of information. Such decline may occur for several reasons according to Line:(2-3) (i) the information is valid, but incorporated in later work; (2) the information is valid, but superseded by later work; (3) the information is valid, but is in a field of declining interest; (4) the information is no longer valid.