[jimktrains2]

It's a running joke in Dr who, where as humanity spreads into the starts there eventually ceases to be any pure humans (and many other alien species) because humans will mate with anything.

I think it's most interesting to think of how fluid what we mean by species really is. We've always known it was fluid, but I think many people never really consider that when thinking about ourselves.

[interestica]

I always wondered if there could be some sort of in-world explanation as to why all the aliens in star trek/wars are so ...humanoid.

[wincy]

I think it’s that all the worlds were seeded by some sort of progenitor race millions of years ago. Also they can interbreed I believe.

[Izkata]

For Star Trek, in-universe this happened at least twice. The relevant episodes are TOS 2x22 Return to Tomorrow [0] and TNG 6x20 The Chase [1].

VOY 3x23 Distant Origin [2] also in-universe establishes convergent evolution is very likely to create humanoids (makes no reference to the other two episodes, as far as I remember, but it's kinda wishy-washy in that it could be highly likely because of the two progenitor species).

That said, there's plenty of non-humanoid aliens. Off the top of my head: Q, the Tholians, the Caretaker's species, the two aliens from TOS 2x01 Catspaw (shown to be tiny and kinda birdlike in the final scenes), and Species 8472.

[0] https://memory-alpha.fandom.com/wiki/Return_to_Tomorrow_(epi...

[1] https://memory-alpha.fandom.com/wiki/The_Chase_(episode)

[2] https://memory-alpha.fandom.com/wiki/Distant_Origin_(episode...

[CobaltFire]

I know some people don't like Enterprise, but it IS in-universe, so lets not forget ENT 1x05 Unexpected [0].

I kid; I know you said "at least".

[0]https://memory-alpha.fandom.com/wiki/Unexpected_(episode)

[Izkata]

Oh, I was referring to progenitor seeding specifically. In terms of interbreeding, there's a few more prominent ones: Spock, B'Elanna Torres, and Alexander Rozhenko and B'Elanna's daughter (who are respectively 3/4 human and 1/4 human, showing there likely isn't an infertility problem like with mules [0]).

(Though I admit that the ENT example was certainly unique in the differing biologies)

[0] https://en.wikipedia.org/wiki/Mule#Fertility

[Izkata]

Dangit I changed the order of "Alexander Rozhenko" and "B'Elanna's daughter" to make it clear they're not related, and forgot to switch the 3/4 and 1/4. Alexander is 1/4 human.

[interestica]

Thanks for this. Definitely curious. (Your comment is so much better than what one could have quickly searched).

Sometimes real constraints (eg costuming/budgets/etc) can result in really clever explanations that strengthen the storytelling/worldbuilding.

[bigbubba]

I guess the ancestors of humans aren't in Earth's fossil record in the Star Trek universe?

[Izkata]

Of the two relevant episodes in my other comment ( https://news.ycombinator.com/item?id=24726335 ), the TOS one explicitly states that that seeding doesn't apply to Earth because of the fossil record and when it occurred (but could explain some of Vulcan's history), while the other one was so early on that Earth was still in the primordial-soup stage.

[nobody9999]

>I always wondered if there could be some sort of in-world explanation as to why all the aliens in star trek/wars are so ...humanoid.

I'd say that for most Sci-Fi Movies/TV there's a couple of reasons:

1. Non-humanoids are less relatable than humanoids;

2. Budgetary restrictions and the relative immaturity of CGI holds us back from creating fairly realistic and relatable alien species.

[interestica]

Yes, that's the real reasons. But by 'in-world' I meant something that could be explained within the story/world-building to justify/explain it away.

[nobody9999]

I know. I just thought I'd throw that out there since no one else did.

[mc32]

I thought that would be dogs which seem to want to hump on anything...

[phkahler]

You haven't met Chad?

[Ygg2]

Dr. Who is wrong. We could not mate with anything amongst the stars. Even if aliens exist they would be radically different. You might as well as bone your VCR.

The act of separation would create new species. Not our drive to bone.

[ladberg]

Doctor Who is also wrong about magic and time travel existing, but it's a fantasy show so it doesn't matter.

[tsimionescu]

Given that we have absolutely no idea what other biological systems could look like, what you're saying seems extremely likely, but not an absolute certainty.

[Ygg2]

It's near certainty. I mean it's not absolutely certain that your nearest pencil won't transform into Jesus and tell you the message that will unite all of humanity. I kinda doubt you would entertain it though.

[tsimionescu]

Yes, true.