Intergalactic disease among humans
 

I've been watching through Stargate Atlantis and something struck me about encountering humans separated by thousands of years on other planets with different eco systems is that you'd get different diseases evolving among different populations and likewise people in different populations not having any immunity to diseases brought by interplanetary visitors.

So how might the same species living on different planets apart for thousands of years affect the development of viruses and bacteria? And what kind interesting roleplaying scenarios could this lead to?

Re: Intergalactic disease among humans
 

Naturally, it's more time than distance, though thousands of years should be enough. With that time span, though, anything deadly to one group should at least be noticeable to the other. Smallpox isn't exactly a fun disease for Europeans, either.

Race to find the cure is a classic scenario. Add in diplomatic complications if the natives notice that the plague got started just when you showed up.

If the primary contact team, or a key specialist, gets sick, you've got either got a less experienced substitute standing in. Or, they're not really that sick, but they have to be kept out of contact with the natives, so you're trying to run diplomacy by radio or inside an germ-proof suit.

You have a sexually transmitted disease cross over. In addition to the public health issues, you now have to determine who's "going native".

Re: Intergalactic disease among humans
 

In even a mildly realistic campagin, the SG teams would have long sense brought home something nasty that the earth has no resistance against.

A big factor in the development of disease is the presence and varity of domestic and wild animals. Some of our nastest disease come from the animals we keep. New planet, new eco system = lots of opp for death

Re: Intergalactic disease among humans
 

Of course they'd also have quarantine procedures after every mission.

Re: Intergalactic disease among humans
 

It would seem to pretty well parallel humans living on different continents being exposed to different diseases. As I recall, Europeans brought smallpox to the Americas and brought syphilis back with them.

I'd expect interstellar disease transmission would be similar. If the seperate ecosystems are compatible enough for humans to eat the food and survive, then they're probably compatible enough for diseases to evolve that can infect humans.

So humans show up on a planet, move in, and come down with local diseases. Either the disease is nasty enough to kill them all off, or it becomes part of their day to day life.* If they're in regular conyact with humans onother worlds, there's a good chance that they'll infect those other worlds.

Worlds that don't interactwith other worlds likely will have reduced immunity to offworld diseases, and will have diseases to which other worlds have little or no immunity.

*It may be important to note that there's a certain evolutionary pressure for a disease to kill off too many of its hosts too quickly. Diseases that do don't get a chance to propagate themselves and die off. Usually, either a disease dosen't kill people (Human rhinovirus), doesn't kill everybody (bubonic plague) or takes a while to kill the host (HIV). A disease that kills 100% of people within a few days isn't going to be spread and will die off itself.

Re: Intergalactic disease among humans
 

It's very likely that a new ecosystem would not present many dangerous contagions. The classic line is that Spock's mom would have had a better chance of conceiving with a horseshoe crab, and the same likely goes for alien viruses. A transplanted ecosystem would be a much bigger hazard.

Bacteria-like infections might be a different issue, as they may function very well on water and sugars, rather than DNA. Likewise toxic chemicals.

Edit: Of course, such an ecosystem is unlikely to support a human population, as well. If the aliens don't use very similar amino acid structures as humans, they aren't food.

Re: Intergalactic disease among humans
 

The OP was referencing the Stargate universe, and asking about Human populations that settle on other planets, then go thousands of years before contact with the rest of the species. You're right about completely alien organisms / ecosystems, though.

Re: Intergalactic disease among humans
 

I'd always assumed that the Ancients terraformed most of the planets where we find human populations (even if the humans themselves were shipped in hundreds of thousands of years later). Otherwise the chances of finding a compatible ecosystem would be negligible.

TeV

Re: Intergalactic disease among humans
 

Actually, if it's humans in an alien ecosystem, they'll still have changes in disease development, due to the lack of viable animal reservoirs.

Re: Intergalactic disease among humans
 

Well, aren't most of the humans in the SG universe in small tribes or tiny, primitive cities? Seems like this would be a repeat of Europe's exploration of North America, only it would be Earth as a whole spreading various diseases all over these new worlds.