Did Col Sumner have the ATA Gene?

[garhkal]

Yeah, in a universe where Sheppard wasn't around, it stands to reason that they would send someone more apt with Ancient technology to defend the city. But the vacuum created by Sheppard could have also led to the siege occurring in a whole different manner. For example, Teyla would have been unlikely to have joined the expedition without him and so that would led to changes in how they went about exploring worlds; they may not have encountered the Genii so they wouldn't have gotten sidetracked dealing with them, they wouldn't have had the Wraith chasing after them because they were tracking her necklace for a period of time, etc. So instead they could have found something to help fight or stall the Wraith either by reaching a planet like the one from "The Tower" sooner or by finding a new one that we never saw (e.g. for a brief window of time there could have been a person on a planet that they didn't go to because Teyla wanted to visit the Hoffmans and that person could have given them a tip about something on another world that would've helped them). They also might have gotten the ZPM in "Brotherhood" without the Genii to contend with and with someone else leading the team, so they might have had the shield when the Wraith first attacked.

Would they even have visited any of those worlds though with out teyla?

The possibilities for the timeline to diverge are endless and any small thing could have sent them on a whole different path. Hell, whoever was in charge of the military might not have had the moral fortitude to leave the ZPM from "Childhood's End." That not only would've given them the shield at full power for a few hours while they try to work something out, (if Teyla wasn't around it's unclear if their plan to the convince the Wraith that they were going to destroy the city would have worked or not so they might have done something differently) but it would have let them see how many drones the city had left before dialing Earth. If you recall, they couldn't find out how many they had without powering up the chair, so Earth sent them the Mark II and just hoped for the best. However, if they sent word that they had so few left, Earth might have sent enough drones from the Ancient platform for them to be able to take out the Wraith's first wave and, again, who knows what they could have done with that extra time.

But how would they have sent the drones there?

[Xaeden]

Would they even have visited any of those worlds though with out teyla?

Of course I don't assume that they absolutely would have gone to any of the same worlds that we saw on the show; these are just speculative possibilities to highlight the point that things could have gone quite differently for them. So if they didn't end up going to any of those same planets in season 1 and instead went to a whole different set then there are a whole new set of opportunities for them to have dealt with the Wraith threat.

That said, my reasoning for suggesting that they may possibly have gone to many of the same planets, just at a faster rate, are as follows:

The planet from "Childhood's End" was one that Teyla had never been to before (she said so in the beginning of the episode). So they selected the planet on their own from those stored in the database. Granted, it's certainly possible that the removal of Sheppard would have led to them also selecting different Stargate addresses from the Ancient database. However, if both universes put together their respective lists using the same non-random filing system (like in Sg-1 where they were using the order established in the Ancient Repository, the Atlantis expedition could have been using the order designated in the Ancient Database) and occasionally threw new addresses into the order like ones Teyla suggested or ones that looked especially interesting based on information gleaned from the database, then they likely would have visited many of the same worlds, just at a different pace. So M7G-677 (the "Childhood's End" planet) would still have been an early planet that they visited and they may have gotten to certain season 2 planets faster under this theory.

As for the address for the planet from "Brotherhood," that was given to them by Janus and that should have happened regardless as otherwise they would have been dead right out of the gate - Weir needed to go back in time to get Janus to set the city to rise when it ran out of power if it was going to survive and if she did that, then there's a good chance she still would have gotten the list of addresses that she gave to the alternate expedition when they awoke her from stasis.

The only role Sheppard played in any of that was that he flew the jumper that brought her back to the past in the main universe, [and then died] so presumably someone else was able to do that in the other reality (as mentioned by Ripple in Space, there were other members of the expedition with the ATA gene from the start, despite claims to the contrary in this thread). It's possible that someone else also would've gone in Weir's place without Sheppard around or that Weir would have acted differently when dealing with the Ancients as, among other things, it's possible her pilot may not have died. Thus, the help Janus gave may have been different or, if someone convinced him in Weir's place, they may not have been able to survive for the full 10,000 years in stasis and thus been able to tell everyone else what he/she learned from Janus. But as that was early on in the divergent set of events and it such a critical moment for the survival of Atlantis, there's a decent chance that things didn't occur all differently from how we saw it in this particular case.

But how would they have sent the drones there?

What I said in regards to the ZPM from "Brotherhood" applies here; since Weir would have had to go back in time to get Janus to help her save the city in either reality, it stands to reason he was also motivated to build the time traveling jumper in the Milky Way. With that jumper, it's quite likely that they still would have been able to recover Ra's ZPM and dial up Atlantis to send supplies and reinforcements before using it to beef up the Daedalus' engines. So they could have sent drones through the gate at the same time.

Alternatively, if they did indeed take the ZPM from "Childhood's End" and used it early on to check on their drone supply, they also would have been able to send a message to Earth much sooner and so even if Sg-1 didn't get that other ZPM for some reason, they had more time to send a ship with supplies. That could have either involved rushing the Daedalus into service so that it had time to make the 3 week journey before the Wraith made it to the city or sending the Prometheus, which likely wouldn't have run into trouble if they heard from Atlantis sooner.

Again, though, these are just examples of how things might have gone differently - I make no claims that anything I put forward as a possibility is anything more than that; a possibility.

[garhkal]

Actually thinking about it, would they even have had to worry about the wraith waking up had shepard and co NOT disturbed teyla and her folk?

[Xaeden]

We don't really know Sumner well enough to say whether or not he would have organized a rescue mission if he wasn't captured (the same goes for whoever would have been charge if he had been and Sheppard wasn't there). A defining characteristic of Sheppard's character is that he holds very strongly to the leave no man behind creed and as such he would always push very strongly and forcibly for it right off the bat. However, he's far from the only one who subscribes to it; others just tend to more carefully weight the situation before ultimately giving the go ahead when they see there's a viable option of extraction in the final hour (as there was in this case). So it's still possible that they would've went to that Hive without him and if they did they probably would still have had to confront the Wraith Keeper to save someone she was interrogating. As a result, there's a good chance she still would have died and the Wraith would have started to wake up in that moment.

But even if they didn't wake up the Wraith then, there still would have been plenty of opportunities for them to do so as they begun exploring the Pegasus galaxy, which would have delayed the siege and, again, led to more time to find something that could have helped them. Although for all we know, their very presence could have eventually woken the Wraith up; we know some Wraith remained awake during the hibernation period and, along with creating Runners, they dealt with societies advanced enough to threaten them like the Satedeans and sent darts out to collect food for a skeleton force that remained awake to guard individual installments. So a new player on Earth's level that would have been rumored to be inhabiting the Ancient city could have easily gotten on the radar of those who were awake through random confrontations or via their network of worshipers. And if they proved too much for those few that remained awake to contend with, they may have initiated wake up protocols as either a preemptive measure or as a means to take Atlantis and find out where these people came from once they became aware that of what a high value target they were.