[mlc9852]

But scientists have been able to combine cells from different species to form chimeras, right?

[stremba]

Yes, but that's possible because the DNA is very similar. That does not imply the ability to interbreed and produce a viable new organism. From what I've seen, the "chimeras" are limited to things such as a mouse whose liver contains some human liver cells, for example. To all appearances, it's a mouse.

[Doctor Stochastic]

But scientists have been able to combine cells from different species to form chimeras, right?

Mostly in vitro; some in vitro combinations have been done. None of these occur in the wild (no cute Latin form, in vildo? in natura?)