Via spells True Polymorph and Shape Change it is possible for any qualified recipient (CR10+ required for the True Polymorph – though ShapeChange only requires one to cast the spell) to gain a very accurate shape of an Aboleth. This linked description (above) suggests all of these creatures have an ancestral-genetic memory of every previous aboleth that ever existed. The Monster Manual (page 14) does NOT say this directly, but does state they have ‘flawless memories’ and will ‘pass their knowledge & experience on from generation to generation’ – without stating how this is done.
Hence this question:
Does having Aboleth shape-form allow gain of their genetic memory?
If so, any wizard, bard or sorcerer / sorceress with access to either of these two spells (or other similarly accurate shape-changing magic) has rapid, accurate and powerful research capacities.