I've thought about this before, and yesterday, I figured that I should blog about it. The Doctor, from the SF show Doctor Who?, is human.
"But wait," says everyone who knows anything about Doctor Who?, "The Doctor is a time lord." You are correct*, and the time lords are human. It seems most likely that the time lords are the result of the evolution of an isolated human population. They seem morphologically and physiologically so similar to humans that their arising completely independently of Earth's biology would have to occur astronomically improbably. And, of course, being evolved from humans means that they are humans.
Let's compare and contrast. On the one hand, time lords have two hearts** and can regenerate. On the other hand, time lords are bipedal plantigrade pentadactyl tetrapods with opposable thumbs, fingernails, two forward-facing color-vision eyes set in closed ocular orbits in skull-enclosed heads with hinged jaws bearing white, bony teeth, pink, fleshy tongues, and soft, pliable lips, altogether capable of speaking human languages, ostensibly with the assistance of vocal chords. They also ingest food through this forward-facing face-holes and apparently have taste buds, too. Time lords also have fleshy, dish-shaped ears on the sides of their heads, hair that grows out of the tops of their heads, along their eyebrows - and, by the way, eyebrows - and reduced or absent hair elsewhere. Also, time lords have skin in that variegated sepia range (dark brown to pale peach-ish) that humans have, as opposed to, say, green or orange. Oh, and time lords can be killed by untreated cyanide poisoning.
That's basically my argument for why the time lords are human. There are other things, but I haven't actually seen proof of them. For instance, I'm assuming that time lords have spinal chords enveloped in vertebrae, which would make them chordates and vertebrates, respectively, but I haven't actually gotten a look at The Doctor's back well enough to tell if there are vertebrae there, so I didn't list them above.
Anyway, if you see anything that I should have included in my lists, then leave a comment below, but, more importantly, if you see someplace where you think that I might be wrong, then leave a comment below.
That's all for now.
*as long as you didn't add a clause asserting that The Doctor is not human
**The fact that time lords have hearts is a similarity, by the way.