I've written a fairly long post on this before, and I don't want to be too repetitive so I won't paste it here. The upshot is: no, there is no evidence to corroborate their existence, and there are good reasons to be sceptical.

As mythical chronology approaches the "present" of when the stories are actually being reported, we gradually start to see figures and events that may well be tied to genuine historical persons and events; but generally speaking we don't start to see corroboration until the very recent mythical past, with foundation legends (semi-legendary founders of real cities like Taras and Cyrene) and some other figures known to have lived in the 8th century BCE (figures like Gyges and Midas). In the absence of corroborating or contradictory evidence, it's usually best to treat anything prior to that as fiction: earlier stuff might have a historical kernel to it, but there's nothing to show that that's the case.