Is it just me, or does anybody else think that science fiction movies depicting a race of hyper-advanced aliens taking over Earth from its "humble inhabitants" have got it all wrong? Barring some intergalactic menace, which is impossible to plan for (unless, go with me on this, we invent space mines! Drop them off at the projected hyperspace routes and BLAMO!), all we have to work with, until we are able to reach into neighboring systems, is our own solar system. Taking into account all known research of the planets within our system, not only does Earth have the most advanced technology of all of them, it may also be the only planet with intelligent (or so we call ourselves) life. As the other planets in our system move through their evolutionary phases, Earth will be much farther ahead of them in the technology race, assuming we don't kill ourselves first. Therefore, when it comes time for someone to invade someone else, I think Earth is most likely to do that invading, rather than any other planet. Of course, we could also go the peace-loving route and build an interplanetary union for the advancement of our system...but do we really want to give up saying, "Take me to your leader," to Mars?
Alternatively...
A theory on the history and future of Earth:
1. Martians build society (past)
2. Mars put in state it is today by global warming, nuclear war, natural causes, and what have you (past)
3. Survivors move to Earth (past)
4. Survivors nurture current Earth society and eventually die out without record of their history (past)
5. Earth develops (present)
6. Mars heals (future)
7. Earth in same state as current Mars (future)
8. Earth repeats cycle (future)
=P
Alternatively...
A theory on the history and future of Earth:
1. Martians build society (past)
2. Mars put in state it is today by global warming, nuclear war, natural causes, and what have you (past)
3. Survivors move to Earth (past)
4. Survivors nurture current Earth society and eventually die out without record of their history (past)
5. Earth develops (present)
6. Mars heals (future)
7. Earth in same state as current Mars (future)
8. Earth repeats cycle (future)
=P