The Preservers, and that seeding thing fromt he Chase explains a bit.
But once I heard about the Voth...
Although I am quite aware that the Flintstones was bullshit, and that man and Dinosaur never really hung out, what if the "fish" that was mans ancestor 40 million years ago when the Voth began their pilgrimage to the Delta Quadrant was taken along as a scrummy food stock that was fed into oceans where ever they went, who 30 million years later left, on thousands of worlds, left thosee oceans, turned into monkeys, then primates, then homonoids and then finally something quite like man today.