Yes! Failure to follow advance directives is one example in which the human species, or in this case, a human life was preserved despite the individual's request to end life-sustaining medical procedures. In the Klavan v. Chester Crozier Medical Center case, Dr. Klavan instructed physicians not to "perform cardio-pulmonary resuscitation, not to use a ventilator or intravenous devices." The doctors who operated and treated him ignored his advance directives and were thus sued for their actions.

Wait...legitimately means legally, right? So if the physicians who performed those medical procedures acted against Dr. Klavan's will, illegally, then my answer doesn't quite fit the question being asked. Alright, I'll research this one.

Is there any situation in which the maintenance of the human species would legitimately take precedence over individual freedoms?

Yes. How about the environment? It is something that human beings have a resonsilbility to do, no matter thye consequences, even if they are to humans. Maintaining the environment encompasses maintaining ourselves, because we need the environment to survive anyway. Even so, the world around us is more important than the welfare of a single/individual human being, as well as something as large as society in general

I mean seriously, who honestly can say that they are more important than all of the animals out there, as well as the welfare of those animals and then the ecology of thsoe animals, plus then we have the natural environment... Come on, anybody more important than all of that?

Well, that depends on what factors into maintenance. As BP says, we could easily be talking about the environment, since that has a global impact and therefore an effect on human beings as a species. But that's hardly the limit. Many scientists say we've far exceeded the maximum population the Earth can support. Should we institute austere measures like in Kurt Vonnegut's "Welcomes to the Monkey House" and sterilize a great deal of the population? It would be effective in dealing with that particular problem. There are several more examples of how maintenance could very easily turn into something with tremendously awful moral implications, even though it would reduce long term problems.

But that's not the only problem with the idea of maintaining the human species. Should we do so in the first place? No, I'm not saying we should wipe ourselves off the face of the earth, but this assumes that humankind has nowhere to evolve to, and therefore that we should be maintained as a species because we are the pinnacle. We could very easily be a stage in evolution. I'll bring up Kurt Vonnegut again, who wrote "Galapagos," a book involving a bunch of passengers aboard a ship headed to the islands of that name and being shipwrecked there. While they were there, a disease spread across all the continents that made everyone sterile. Only those on the Galapagos were fertile, but because of their changed environment and what was available, they evolved over a very long period of time into something more suitable.

So the question isn't quite so simple. Should we focus on maintaining the species? To an extent. We shouldn't sacrifice anything and everything, though we could certainly make many of the necessary changes to keep the species afloat. At the same time, I feel we shouldn't impede forward progress of the species.