Selection shadow

(a) The survival rate of a population decreases as individuals age, but the reproduction rate remains constant. (b) The reproduction probability peaks early in life at sexual maturity and then steadily decreases as an individual ages, with the remaining share of the population decreasing with age as they enter the selection shadow.

The selection shadow is a concept involved with the evolutionary theories of aging that states that selection pressures on an individual decrease as an individual ages and passes sexual maturity, resulting in a "shadow" of time where selective fitness is not considered. Over generations, this results in maladaptive mutations that accumulate later in life due to aging being non-adaptive toward reproductive fitness.[1] The concept was first worked out by J. B. S. Haldane and Peter Medawar in the 1940s, with Medawar creating the first graphical model.[1]

  1. ^ a b Fabian, Daniel; Flatt, Thomas (2011). "The Evolution of Aging". Scitable. Nature Publishing Group. Retrieved May 20, 2014.