Mutualistic relationships in evolution

Abstract

Mutualizam je interspecijski odnos koji podrazumijeva međusobnu korist partnera, te je neizostavni faktor svakog ekosustava. Cilj je ovog rada dati općeniti pregled mutualizma, od svojstava koja utječu na uspostavljanje odnosa, opasnosti koje prijete njegovoj održivosti, do mehanizama kojima se kontrolira održavanje, te mogućih budućih smjerova istraživanja teme stabilnosti mutualizama. Naglasak rada je na propitkivanju stabilnosti mutualizma iz dva kuta – pobližem razmatranju a) utjecaja varalica na stabilnost i b) korelacije fluidnosti dinamike (pomaci u parazitizam-mutualizam kontinuumu u ekološkom vremenu) i stabilnosti. Varanje se pokazalo kao pojava koja se učinkovito stabilizira sankcijama protiv varalica, reproduktivnom izolacijom vrsta varalica i vrsta mutualista na istom domaćinu, te asimetričnom kompeticijom. Dinamična priroda mutualizma (pokazana na primjeru Wolbachia/člankonožac mutualizam), tj. iznimna ovisnost prirode odnosa o ekološkim čimbenicima, pokazala je da je mutualistički odnos ipak interakcija s previše varijabli da bi se donosile jasne hipoteze za evolucijsku budućnost odnosa. Genetička svojstva prisutna prije uspostave mutualističkih odnosa, uz koevoluciju mutualista, također su se pokazala kao važan faktor u uspostavljanju odnosa i održavanju stabilnosti. Dodatno, klimatske promjene su se pokazale kao značajna prijetnja održivosti mutualizma u budućnosti, čime se naglašava kako je bitno u budućnosti usmjeriti pažnju na konzervaciju mutualističkih odnosa, za dobro planeta i održivosti ekosustava kakve poznajemo.Mutualism is an interspecies relationship that implies the mutual benefit of partners and is an indispensable factor of any ecosystem. The paper aims to give a general overview of mutualism, starting from the properties that affect the relationship, the dangers that threaten its sustainability, to the mechanisms for maintaining it, and possible future directions for research on the topic of mutualism stability. The emphasis of the paper is on two different points of view on the stability of mutualism - a closer examination of a) the influence of cheaters on the stability, and b) correlations between the fluidity of the dynamics (shifts in the parasitism-mutualism continuum in ecological time) and stability. Cheating has proven to be a phenomenon that is effectively stabilized by sanctions against cheaters, reproductive isolation of cheaters and mutualist types on the same host, and asymmetric competition. The dynamic nature of mutualism (exemplified by the Wolbachia/arthropod mutualism), i.e., the extreme dependence of the nature of relationships on the environmental factors, has shown that mutualistic relationships are in fact interactions with too many variables to hypothesize their evolutionary future. Genetic traits present before the establishment of mutualistic relationships have also proven to be, beside the co-evolution of mutualists, an important factor in establishing relationships and maintaining stability. Furthermore, the climate change has proven to be a substantial threat to the sustainability of mutualism in the future, thus emphasizing the importance of focusing on the preservation of mutualistic relations in the future, for the good of the planet, and the sustainability of the ecosystems as we know it