>>51413128I think in-universe it makes sense that they'd be logged seperately, it implies canonically that early researchers didn't really understand pokemon genders.
>be researcher>find pokemon called nidoran>they look sorta similar but are different colours and evolve into distinct evolutions>guess they must be different pokemon>add it to the dex and move on>few years later (aka GSC time period)>people realise that most pokemon actually have genders>realise that many species have more subtle forms of sexual dimorphism that went previously unnoticed (Scyther, Venusaur, Seaking, etc)>pokedex has already been codified with NidoranF and NidoranM as distinct species>fortunately pokemon breeding has also just been discovered and it also turns out that there are some breeding complications with Nidoking and Nidoqueen, so it seems you also lucked out on discovering some kind of interspecies distinction that does seperate the two lines>commitee decides not to re-classify Nidorans as the same species but learns to take more care in approaching further species that exhibit sexal dimorphism to determine if they're part of the same species (ie Male/Female Meowstic) or if they classify as unique species (like Volbeat and Illumise) 