The Origins of Aging: Evidence that Aging is an Adaptive Phenotype
Notice bibliographique
Résumé
BACKGROUND: Aging can be defined as the time-related decline in biological functions which ultimately results in organismal death. Beyond the stage of reproductive maturity as fertility declines, cell and tissue functions come under reduced selection pressure since organismal survival is considered no longer an evolutionary priority. Repair mechanisms become less robust and the resulting stochastic accumulation of tissue and genomic damage is believed to underlie the aging process. The objective of this review is to challenge this construct and to present evidence that aging represents a species-specific adaptive developmental program. METHODS: Through a review of published data, the cellular aging programs of both single cell and multicellular organisms are described. Since all organisms live in communities (ecosystems) of diverse species, the role of multi-level selection is discussed within this context and a proposal is advanced that aging represents an adaptive phenotype. RESULTS: Single cell organisms evolved an aging phenotype in which the primary feature was replicative arrest prior to cell death. The evolution of multicellularity represented the emergence of a new level of biological organization. Multicellularity required cell-cell cooperation as well as a division of labor. In simple multicellular organisms aging was rooted in an age-related decline in stem cell function (renewal and differentiation). In complex multicellular organisms cellular aging/ death programs (senescence, autophagy, apoptosis) were used as a form of cell "altruistic" suicide carried out for the benefit of the whole organism (morphogenesis, tissue repair and maintenance). Organisms do not live in isolation. Species occupy ecological niches and communities of diverse species comprise an ecosystem. Ecosystems are highly regulated and structured biological organizations. The effective functioning and productivity of an ecosystem is determined by its biological diversity and relative species densities. Multilevel selection acts to balance optimal functioning of both the whole ecosystem and its compositional species/organisms. CONCLUSIONS: Organismal aging and death programs are adaptive; these programs provide a mechanism for regulating species population densities within the constraints imposed by the ecosystem organization. A unique feature of humans has been the development of a second inheritance system, culture. Through cultural practices, humans have expanded our ecological niche to be global in size. Our technology enriched urban ecosystem is very different from natural ecosystems. Our future evolution, including aging and lifespan, will be determined by our unique urban ecosystem through geneculture co-evolution.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,003 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».