Zum vorhergehenden Beitrag von Reber:
„Ameisen könnten der Schlüssel zu ewiger Jugend sein“, so der Titel des verlinkten Beitrags, und
„Einige-ameisen-sind-uns-deutlich-voraus-sie-altern-ueberhaupt-nicht":
https://www.wired.de/collection/latest/ ... aupt-nicht Um Aufmerksamkeit zu erregen, muss man heutzutage nur einen Bezug zum Menschen herstellen, und sei er noch so bemüht an den spärlichen Haaren der Ameisen herbeigezogen!
Ein Großteil der menschlichen Gehirnzellen hat eine Lebenserwartung von 70 und mehr Jahren. Es ist eine Binsenweisheit, dass Ameisenköniginnen sehr viel länger leben als die Arbeiterinnen. Entsprechend muss ihr Gehirn auch bis nahe an 30 Jahre funktionsfähig bleiben. Da wäre es sicher interessant, die Lebensdauer der Gehirnzellen solcher Königinnen heranzuziehen. Man muss dazu nicht 30Jahre warten, schon 2-3 Jahre alte Königinnen könnten relevante Ergebnisse liefern. Aber auch das dauert in der Zeit der “fast-food-science“ zu lange.
Interessant wäre vor allem der Vergleich älterer (fertiler) Königinnen mit unbegattet gebliebenen, denn die hohe Lebenserwartung gilt nur für solche, die begattet sind und sich fleißig der Fortpflanzung widmen. Unbegattet in der Rolle von Arbeiterinnen leben sie nicht länger als diese, wie wir selbst in vielen Laborversuchen gesehen haben.
Hier gibt es den kompletten Text der verlinkten Arbeit:
https://www.researchgate.net/profile/Ja ... 7291b1.pdf Abstract: Analyses of senescence in social species are important to understanding how
group living influences the evolution of ageing in society members. Social
insects exhibit remarkable lifespan polyphenisms and division of labour,
presenting excellent opportunities to test hypotheses concerning ageing and
behaviour. Senescence patterns in other taxa suggest that behavioural performance
in ageing workers would decrease in association with declining
brain functions. Using the ant Pheidole dentata as a model, we found that
120-day-old minor workers, having completed 86% of their laboratory lifespan,
showed no decrease in sensorimotor functions underscoring complex tasks
such as alloparenting and foraging. Collaterally, we found no age-associated
increases in apoptosis in functionally specialized brain compartments or
decreases in synaptic densities in the mushroom bodies, regions associated
with integrative processing. Furthermore, brain titres of serotonin and
dopamine—neuromodulators that could negatively impact behaviour through
age-related declines—increased in old workers. Unimpaired task performance
appears to be based on the maintenance of brain functions supporting olfaction
and motor coordination independent of age. Our study is the first to comprehensively
assess lifespan task performance and its neurobiological correlates
and identify constancy in behavioural performance and the absence of
significant age-related neural declines.
Es ist jedenfalls eine sehr gründliche und vielseitige Arbeit aus einer sehr großen Wissenschaftssparte, der Altersforschung!
Eine weitere Arbeit aus 2014, von zwei der Autoren: Ysabel Milton Giraldoand and James F. A. Traniello: Worker senescence and the sociobiology of aging in ants, Behavioral Ecology and Sociobiology 12/2014.
http://link.springer.com/article/10.100 ... -4#/page-1 Abstract:Senescence, the decline in physiological and behavioral function with increasing age, has been the focus of significant theoretical and empirical research in a broad array of animal taxa. Preeminent among invertebrate social models of aging are ants, a diverse and ecologically dominant clade of eusocial insects characterized by reproductive and sterile phenotypes. In this review, we critically examine selection for worker lifespan in ants and discuss the relationship between functional senescence, longevity, task performance, and colony fitness. We did not find strong or consistent support for the hypothesis that demographic senescence in ants is programmed, or its corollary prediction that workers that do not experience extrinsic mortality die at an age approximating their lifespan in nature. We present seven hypotheses concerning how selection could favor extended worker lifespan through its positive relationship to colony size and predict that large colony size, under some conditions, should confer multiple and significant fitness advantages. Fitness benefits derived from long worker lifespan could be mediated by increased resource acquisition, efficient division of labor, accuracy of collective decision-making, enhanced allomaternal care and colony defense, lower infection risk, and decreased energetic costs of workforce maintenance. We suggest future avenues of research to examine the evolution of worker lifespan and its relationship to colony fitness, and conclude that an innovative fusion of sociobiology, senescence theory, and mechanistic studies of aging can improve our understanding of the adaptive nature of worker lifespan in ants.
MfG,
Merkur