{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T11:12:00Z","timestamp":1773659520141,"version":"3.50.1"},"reference-count":0,"publisher":"Hindawi Limited","license":[{"start":{"date-parts":[[2006,1,1]],"date-time":"2006-01-01T00:00:00Z","timestamp":1136073600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Scientific World JOURNAL"],"published-print":{"date-parts":[[2006]]},"abstract":"<jats:p>A large set of data suggests that progressive reduction of fitness and senile decay in vertebrates are in correlation with the decline of cell replication capacities. However, the limits in such capacities are hardly explained in evolutionarily terms by current gerontological theories that rule out fitness decline as something genetically determined and regulated, and therefore somehow favored by natural selection.Four theories are tested as possible explanations of the \u201cincreasing mortality with increasing chronological age in populations in the wild\u201d (\u201cIMICAW\u201d[1]), alias \u201cactuarial senescence in the wild\u201d[2], and of the observed negative correlation between extrinsic mortality and the ratio between deaths due to intrinsic mortality and deaths due to extrinsic mortality. Only the theory attributing an adaptive value to IMICAW allows an evolutionary explanation for it and for the aforesaid inverse correlation, while the other three theories (\u201cmutation accumulation\u201d, \u201cantagonistic pleiotropy\u201d, and \u201cdisposable soma\u201d th.) even predict a positive correlation.Afterwards, the same theories are tested as possible explanations for the \u201cstate of senility\u201d[3], namely the deteriorated state of individuals in artificially protected conditions (captivity, civilization, etc.) at ages rarely or never observable in the wild. With the distinction between \u201cdamage resulting from intrinsic living processes\u201d[4], alias \u201cage changes\u201d[5], and \u201cage-associated diseases\u201d[4,5], the same theory explaining IMICAW allows a rational interpretation of the first category of phenomena while another theory, the \u201cmutation accumulation\u201d hypothesis, gives an immediate interpretation for the second category.The current gerontological paradigm explaining the increasing mortality with increasing chronological age as consequence of insufficient selection should be restricted to the \u201cage-associated diseases\u201d. For IMICAW, it should be substituted with the concept of a physiologic phenomenon genetically determined by a balance of opposite selective pressures \u2014 strictly in terms of kin selection \u2014 and, for \u201cage changes\u201d, with the action of the same IMICAW-causing mechanisms at ages when selection becomes ineffective.<\/jats:p>","DOI":"10.1100\/tsw.2006.209","type":"journal-article","created":{"date-parts":[[2007,5,25]],"date-time":"2007-05-25T11:38:32Z","timestamp":1180093112000},"page":"1086-1108","source":"Crossref","is-referenced-by-count":26,"title":["Evolutionary Explanations of the \u201cActuarial Senescence in the Wild\u201d and of the \u201cState of Senility\u201d"],"prefix":"10.1100","volume":"6","author":[{"given":"Giacinto","family":"Libertini","sequence":"first","affiliation":[{"name":"Caivano 80023, Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"98","container-title":["The Scientific World JOURNAL"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/downloads.hindawi.com\/journals\/tswj\/2006\/782531.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/tswj\/2006\/782531.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2016,8,23]],"date-time":"2016-08-23T15:17:35Z","timestamp":1471965455000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.hindawi.com\/journals\/tswj\/2006\/782531\/abs\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2006]]},"references-count":0,"alternative-id":["782531"],"URL":"https:\/\/doi.org\/10.1100\/tsw.2006.209","relation":{},"ISSN":["1537-744X"],"issn-type":[{"value":"1537-744X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2006]]}}}