Histone demethylase that specifically demethylates 'Lys-36' of histone H3, thereby playing a central role in histone code (By similarity). Has a role in regulating lifespan. 2 2-oxoglutarate + N(6),N(6)-dimethyl-L-lysyl(36)-[histone H3] + 2 O2 = 2 CO2 + 2 formaldehyde + L-lysyl(36)-[histone H3] + 2 succinate Binds 1 Fe(2+) ion per subunit. The JmjC domain mediates the demethylation activity. RNAi-mediated knockdown introduced at L1 and young adult stages increases lifespan by 12% and 15% respectively. Belongs to the JHDM1 histone demethylase family.