I fail to see any possible ambiguity. You have ancestors. Your ancestors have ancestors. Likewise, Homo sapiens, the species, has ancestors, and at some point those ancestors are also ancestral to chimpanzees. And so on back through time until the ancestors in question are also ancestral to all extant species and extinct ones too. Admittedly horizontal transfer of various sorts might introduce somewhat different ancestral pathways for different bits of your genome, but this becomes a source of real ambiguity only prior to the emergence of eukaryotes, and things are pretty straightforward in the group from there on. Bacterial lineages are more problematic, but not unmanageably so. There is clearly no evidence of separate creation of any species.
I have to say that it’s strange that at this late date you don’t know what “common descent” means.