One word:
Parasites.
Just imagine mating with those early humans who had not even the slightest concept of a bath…
I threw that one out there elsewhere. Although not so succinctly.
The ending not being catastrophic for the survivors requires a willing suspension of knowledge by the viewer. If not, one is forced to conclude that the lives of most, if not all, of them will be Hobbesian - nasty, brutish and short.
Then again, given the condition of the fleet, dwindling resources, etc. - they had no choice but to settle on Earth. But everybody following Lee’s dictum in zombie like fashion to abandon most of their technology, split up into “tribes” (yep) and intermingle and mate with the locals (to whom they would appear as “lords” - yep again) in order to break the cycle (why does it do that by the way, other than Lee says so?), while perhaps pretty good story telling, is just plain stupid.
If OT had been around and had anything to say about it - find a great spot and “rebuild” New Caprica - ships on the ground and all. Oh yeah, don’t forget to bring to the surface sick bay from Galactica, etc. What’s the worry of a “repeat” - the bad Cylons are all kaput. (Interestingly, Ron Moore said in an interview that to keep the running time of the finale under control they cut a scene of the nuked Colony falling into the black hole as it was blowing apart.)
With a population of about 40,000 and what’s left of their technology, they would have a real chance of surviving and prospering. However, even then it would not be “easy”. Recall how relatively primitive conditions were on New Caprica even before the Cylons showed up - one year into having settled there?
“My” ending, however, while logical, would have been total craaaaap.
I feel that way about so many books I love - if only X had been done this way instead, then the whole problem would never have happened! But that’s the point. Without the problem, the art isn’t there 
But that doesn’t mean that it isn’t immensely frustrating at times.
I think it was Picasso who said that art is not concerned with facts, it’s concerned with truth. Let it go.
Yes, logic can often ruin stories. When got out of the theater after seeing Titanic, I was kind of annoyed that Rose just didn’t stay on the life boat she was originally on. If she had then Jack would have been able to stay on the floating debris and been saved…
I had trouble imagining Lee getting it on with Grak the Cave Woman, so I thought maybe they were neanderthals (or a similar biped that was not our genetic ancestor).
I also wonder whether Paula and the Balcubines (sounds like a band playing CBGBs in the late 80s…) became a tribe of amazons.
No kidding. I’m starting on Mayflower by Nathaniel Philbrick. I’m only a few chapters in and already half the people are dead. And Plymouth wasn’t the first English settlement. It and Jamestown were just the first to succeed, i.e. everyone didn’t die.
Hee! To be fair though, I bet the colonials would have introduced all kinds of diseases that they’re not used to being exposed to either, like the common cold, or Hot Dog with his rash.
So, it’s a pretty fair game on both sides, maybe? 
You know why the MtDNA eve is Hera and not those of the humans who evolved on earth?
Because they were wiped out by Hotdog’s rash.
They would’ve not lasted long as Amazons. They would likely have conquered their men. Paula would have quelled opposition quickly as she would ruthlessly point out how the men would be getting the better part of the deal.
The Rash is one of the strangest pseudo-characters. It would definitely be in play if Hotdog settled on our Earth.
That would be way too logical.