Several experimental studies on different model organisms have shown that longevity can be associated with stress resistance. That fact suggests that better coping with environmental challenges plays a role in lifespan regulation. Obtaining stress resistance through an evolutionary process might help to enlighten aging theory. To examine this hypothesis, we performed experimental evolution experiment on Caenorhabditis elegans. During their development and life, two populations of worms were exposed to high temperature and separately to UV radiation for few generations. One population among them became resistant to high temperature and one to UV irradiation. Those populations were then analyzed with heat stress assay and lifespan assay. Worms that had better response to high temperature as an evolution constraint have shown a significantly better response to heat stress comparing to wild-type. This resistance appeared even several generations after pre-exposure to lower sublethal temperature, so is most unlikely to be the consequence of hormesis. Considering that experimental evolution was done on a relatively small number of generations, lifespan assay of those worms showed no significant difference from the wild type. For UV evolved worms there was no significant change in both assays, that might mean that resistance to UV is harder to acquire. Observation of their condition and hazard ratio indicate that irradiation might have caused damage instead of resistance. Both experimental populations probably have yet to reach the significant evolution change that would lead to increase of stress resistance and increase of their lifespan.

Više eksperimentalnih istraživanja na različitim modelnim organizmima dokazuje da se dugovječnost može povezati s otpornošću na stres. To upućuje da bolje nošenje s okolišnim izazovima igra ulogu u regulaciji životnog vijeka. Postizanje otpornosti na stres kroz evoluciju moglo bi pomoći u rasvjetljavanju teorije starenja. U svrhu ispitivanja te hipoteze, proveli smo eksperimentalnu evoluciju na vrsti Caenorhabditis elegans. Dvije populacije crva bile su tijekom njihova razvoja i života podvrgnute uvjetima povišene temperature i UV zračenja kroz više generacija. Među njima pojavila se jedna populacija otporna na visoku temperaturu i jedna na UV zračenje. Te su populacije zatim bile podvrgnute testovima podnošenja visoke temperature ('heat stress assay') i duljine životnog vijeka ('lifespan assay'). Crvi koji su dobro podnosili višu temperaturu, pokazali su značajno bolji odgovor na toplinski stres u usporedbi s divljim tipom. Ta otpornost pojavila se i nekoliko generacija nakon izlaganja nižoj neletalnoj temperaturi, stoga vjerojatno nije posljedica hormeze. S obzirom da je eksperimentalna evolucija provedena na relativno malom broju generacija, životni vijek tih crva nije se znatnije razlikovao od divljeg tipa. Crvi izloženi UV zračenju nisu pokazali značajnu razliku na oba testa, što može značiti da je otpornost na UV zračenje teško postići. Omjer smrtnog rizika kao i opažanja njihovog stanja upućuju na to da je izloženost UV radijaciji možda uzrokovala oštećenja, a ne razvoj otpornosti. Obe eksperimentalne populacije možda tek trebaju proći kroz značajniju evolucijsku promjenu koja će dovesti do povećane otpornosti na stres i produženja njihovog životnog vijeka.