▁path ways ▁evol ved ▁first ▁to ▁make ▁energy . ▁After wards , ▁they ▁evol ved ▁to ▁fix ▁carbon ." ▁ ▁The ▁scient ists ▁further ▁proposed ▁mechan isms ▁which ▁would ▁have ▁allowed ▁the ▁min eral - bound ▁proto - cell ▁to ▁become ▁free - l iving ▁and ▁for ▁the ▁evolution ▁of ▁ac et ate ▁met abol ism ▁into ▁m eth ane , ▁using ▁the ▁same ▁energy - based ▁path ways . ▁ ▁They ▁spec ulated ▁that ▁M . ▁ac et iv or ans ▁was ▁one ▁of ▁the ▁first ▁life forms ▁on ▁Earth , ▁a ▁direct ▁desc endant ▁of ▁the ▁early ▁proto - cell s . ▁ ▁The ▁research ▁was ▁published ▁in ▁M ole cular ▁Bi ology ▁and ▁E volution ▁in ▁June ▁ 2 0 0 6 . ▁ ▁Rec ently ▁research ers ▁have ▁proposed ▁an ▁evolution ▁hypothesis ▁for ▁ac et ate ▁kin ase ▁and ▁ph osph o ac et yl ▁transfer ase ▁with ▁genom ic ▁evidence ▁from ▁M eth anos arc ina . ▁ ▁Scient ists ▁hypoth es ize ▁ac et ate ▁kin ase ▁could ▁be ▁the ▁ur kin ase ▁in ▁a ▁major ▁protein ▁super family ▁that ▁includes ▁act in . ▁ ▁Ev idence ▁suggests ▁ac et ate ▁kin ase ▁evol ved ▁in ▁an ▁ancient ▁hal oph il ic ▁M eth anos arc ina ▁gen ome ▁through ▁dup lication ▁and ▁diver gence ▁of ▁the ▁ac et yl ▁co A ▁synth et ase ▁gene . ▁ ▁Ro le ▁in ▁the ▁Perm ian – Tri ass ic ▁ext inction ▁event ▁It ▁was ▁hypoth es ized ▁that