...Which is also why he wears a mustache. For a Cardassian, it's a bit like flaunting one's warts, but at least it accentuates the difference.
"The Chase" suggests these generic ancient humanoids seeded the galaxy with material that would create further humanoids eventually. But this doesn't mean that they were the only ones to do so, or that all humanoid life is the result of seeding by them or others. It just shows that their technique triumphed over competition, resulting in the statistical victory of their code being found in dozens of local species (and perhaps millions of species overall) in the 24th century.
Really, such a driven culture would be expected to pursue its goal with aggressive technology that identifies, engages and ruthlessly destroys (or co-opts) competing seeding programs. And so would other, similar cultures, meaning that the "evolution" seen in action in the Trek universe is in fact just a battlefield of weird biotechnologies.
Which is what the evolution seen in action in our universe is all about, too. It's just that we know for sure that in Trek, the technologies were given definite goals by a humanoid intelligence, whereas our competitors have incredibly fuzzy goals they pursue with indifference, always settling for the barely adequate and never thinking ahead...