XII.6.3.1.1 Interspecific competition theory assumes that ageing and death of old individuals enables populations to adapt to changing conditions

The theory based on interspecific competition seems to be the least probable at the present time (Nusbaum 1996).According to this theory, it is advantageous for a species if its members age and die and make room for new individuals of the particular species.In this way, the population can gradually evolve to adapt to changing living conditions.A basic drawback of this theory is that it does not take into account the simultaneous opposite action of individual selection.It could be advantageous for a species as a whole if faster and better adaptation of the gene pool of the population to external conditions is facilitated through programmed death of individuals.However, it is advantageous for the individual member of the population if he ages as slowly as possible and lives as long as possible and consequently leaves the greatest number of progeny.Any mutation that causes slowing of ageing in its carrier will increase his individual fitness and will thus have a tendency to increase its frequency in the population and finally become fixed, without regard as to whether its fixation reduces the chance of long-term survival of the entire species.  The theory of interspecific competition and programmed ageing is also thrown into doubt by the fact that, in captivity, individuals of various species frequently live to a much greater age than in nature {11199}.

Was this information useful for you?
The classical Darwinian theory of evolution can explain the evolution of adaptive traits only in asexual organisms. The frozen plasticity theory is much more general: It can also explain the origin and evolution of adaptive traits in both asexual and sexual organisms Read more
Draft translation from: Evoluční biologie, 2. vydání (Evolutionary biology, 2nd edition), J. Flegr, Academia Prague 2009. The translation was not done by biologist, therefore any suggestion concerning proper scientific terminology and language usage are highly welcomed. You can send your comments to flegratcesnet [dot] cz. Thank you.