Earth
Or the chip eaters.
Episode 1: Thematic structure referencing human culture in the present, busy world, regular direct references to money, obsession with self, and fear and paranoia ensuring humans take their eye off the ball, and end up letting the wrold slip away from under their feet.
Episode 2: The consequence of human culture in the future. In episode 2 we see an example of what we evolve into. Cassandra being greedy, self obsessed, selfish, ruthless.
A hedonistic voyeurism, where the death of worlds is seen as "fun" and entertainment. The great and the good are "rich".
We see RTD give us a snapshot of cultural life today, and what we tend to stress value on now, and then in Episode 2, we get to see what we can become as a consequence of leading a chip eating, television watching culture, who are just saving ourselves (looking after number 1, I'm alright Jack)
Cassandra; "Earth is the hotbed of civilisation, humans "mingle" and become mongrels. Jabe and the Forest of Cheem are examples of such human descendants in the future.
The Doctor in Episode 4: Aliens of London...just after the supposed alien spacehip crash-lands into the Thames, he is more than happy, and said it now gives humans the opportunity to "Expand"...i.e. go forth and explore the Universe.
Proto-humans, and Digi-humans are other expressions used by Cassandra to imply that humans evolve into other aliens.
It's not beyond the realms of possibility that some of the aliens who try to launch invasions of Earth, are indeed products of Human evolution in the future.
Maybe most of these aliens we see in the series are a product of natural evolution of the human race.
The Doctor seems to relish the thought of the potential of humans are capable of. In episode 1 he maintains to the Nestene that these "stupid people are only just starting, they are capable of so much more". The Doctor uses this as a defence to stop the Nesten attacking them, but the Doctor may not realise that what he just said was the main problem. The Nestene are afraid of what humans become, and what humans become is the root of all their problems, so what the Doctor said is not a good defence of humans, and is like a red rag to a bull as far as the Nestene is concerned.
In Episode 4, when the alien spaceship crashes, the Doctor is optimistic to Rose, and tells her this is an opportunity for the human race to "expand". He thinks that the human race expanding and travelling the universe is a good thing.
But here again is where the problem lies. It is maybe the BIG mistake that the Doctor is making. It could be that the human race expanding and exploring space is the reason why the Time War started in the first place.
The Doctor, by his very act of encouraging humans to be more advanced than they are now is the crux of the problem. He sees the negative aspects of humans, and feels that by encouraging them to better themselves the consequences will be good. But it could be this that is the fundamental mistake he is making. Although he thinks this is a good idea for humans to develop, his interference in promoting this is what may lead on to the humans being even more dangerous.
His very existence now, and actions he takes right now, could be the very thing that leads to tha very thing he wants to avoid. But he doesn't see the error in his ways.
Whatever is happening right now, and the Doctor's participation in events, leads to a predestined fate he may think he is avoiding, but in actuality is leading everything to the very fate he would want to avoid.
The Doctors own interference in events now could mean that he is opening a Pandora's Box, where he is helping the human race advance before they are ready, and unleashing the negative potential of humans on the universe.
Humans may be the ancestors of the Daleks.
The Gelth may even be Humans of the future, or the Gelth may even be Daleks, we only see the spirit form of the Gelth, the Dalek is just a metal shell.
Many of the aliens we see could be descendants of humans. They maybe all represent the greedy, selfish sides of the human character. Their negative character traits are also what could be described as the negative traits of human nature.
Religion/Pseudo-religion
Apparently one episode carries a story involving a Big Brother reality game show. If this is true, then it would be likely to be another hint towards the theme of controlling the public via the media with a propaganda style theme. It could probably also be a substitute for religion, as worship of these types of shows can border on being almost pseudo-religious in nature.
It would also tie in with the idea of human society being obsessed with frenzied worship of anything that encourages their base urges to be addicted to hedonistic, empty entertainmment.
Again, it would tie into the snapshot of British society alluded to back in episode 1, and occasionally throughout the series whenever The Doctor shows contempt for the chip eaters who just work sleep and watch telly, being oblivious to what really matters in life, and eventually "letting go" and losing what's important in life when it's all too late.
Maybe greed for living a hedonistic, selfish, self-indulgent way of life is a possible metaphor for religion that may be used if religion in itself doesn't become a feature of this series.
I think worship of some kind will feature in one way or another. There have been enough digs at human society in the story so far to imply this as a possibility.
I do think that the human race at some point in the future develops a form of religion, or pseudo religion.
The references to Big Brother give us a clue there. Amongst money, status, and self interest, television culture is something that the public seems to worhip more and more these days. Even the reference to Heat magazine is another tiny little clue about where the writers are coming from.
British society right now tends to worship a nothingness, and latches onto crazes, and embraces them fully as the next "wicked" "cool" thing.
With the absence of religion in society, the worship of all things to do with money and celebrity status fills this vacuum.
When in this state of consciousness, its very easy to introduce thought control, and manipulate the public.
When the public are wrapped up in modern culture, they tend not to notice things like "invasions happening right under their feet", like the Autons, or the Slitheen.
I think a lot of this is reflected in the writing, where the writers have made a point of the Doc being arrogant towards humans in general, and refering to them as chip eaters who watch telly, and regularly pours scorn on them or derides them.
In episode 2 we are given the ultimate example of a voyeuristic society where people actually see the death of a planet as entertainment to gawp at.
I think that many indications are there that the human race is fickle, and that our way of life is such that a new idea can be introduced, and embraced wholeheartedly if presented in an effective manner.
So a new religion can potentially crop up at any time.
In episode 11:Boom Town, a character is introduced to the story that the Doctor thought was long dead. It sounds possible that this might be another Time Lord. It's entirely possible that from a human's eyes, somebody like a Time Lord could be worshipped as a god.
(Big)Bad Wolf
What does this mean?
I won't go into this too much as plenty has already been speculated about this so far, and I don't want to risk repeating too much of what others and myself have already posted elsewhere.
It appears at this moment in time that this expression refers to the Tardis and/or superior technology.
It might mean more, or something else entirely, but right now I don't have much that points to anything else.
In Episode 1, The Nestene Consciousness said it when it first saw the Tardis, and it invoked fear, paranoia, and anxiousness.
The Moxx of Balhoon spoke to The Face of Boe in Episode 2, and said "Indupitably, this IS the Bad Wolf Scenario. I find the laxity of the unknown (missing word) multiverse...<fades out>"
Again, in Episode 2, the small blue aliens who moved the Tardis repeated "Bad Wolf", although you don't catch it on first hearing.
In Episode 3, things take on a different light...When the servant girl Gwyneth reads Rose's mind she says that she knows Rose has seen "The Big Bad Wolf".
The word "Big" adds more mystery to this running theme.
In the trailer for episode 4"The Aliens of London, we see "Bad Wolf" spray painted onto the Tardis...Not "Big" Bad Wolf.
At this point in time there is more evidence to support the idea that refers to the Tardis itself. It may refer to either The Doctor, or Rose, but there is less evidence to support that at the moment.
According to Episode 2, we know that on platform one of the observation space station, religion, weapons, and the use of teleportation devices under the peace treaty.
A Tardis being a teleportation device, must be seen as a threat, and appears to have been something prohibited due to a war.
Bad Wolf ,Tardis breaking into a time line, or a dimension???(As in the Wolf breaking into the houses of the three little pigs)
It appears that Bad Wolf is another “meme”, and it looks like we might have to wait for further episodes to air before we can go much further in knowing what it will mean. There has already been much speculation about the meaning of Big Bad Wolf, that we may have come to a dead end for now. So I won’t go on about this any further here.
Tardis Technology
Obviously the Tardis has time travel technology, but what may also be of use is another technology it contains.
Telepathy and the abilty of thought control.
This type of technology would be very powerful, and in a war would be very useful in controlling people and keeping them "on message". Thought control would be a very powerful weapon to employ in a propaganda war.
Episode 2 highlighted these powers. Not only can it enable messages to be interpreted a certain way, the tabloid media would love to be able to use "psychic paper" as demonstrated in Episode 2.
The technology within the Tardis not only holds the secret to Time Travel, it also has the potential power to brainwash people.
Superior technology in the hands of humans would be the key element that would make Earth major key players in this Time War.
I don't think it's any mistake that the charcter that Bruno Langley plays in a future episode is that of a young "scientific genius".
It is almost a major clue that in a future story that Earth is trying to develop a technology of some sort that is a key part of this story.
It's not like he's cast as a chef, or a bank clerk, or something.
Meme
"The adherence of the repeated meme"
In episode 2, the appearance of the IPod and Britney Spears jokes are examples of a meme. And there the concept is introduced to the viewer of the show, coupled with the script reference when Cassandra's cyborgs are used to explain the concept, and subtely help the viewer link the Ipod and Britney jokes to the term.
i suggested that the term "Bad Wolf" could be a "meme" in this story. And although possibly merely being the tag of a kid spraying graffiti, can transform into something of far greating meaning and significance thousands of years into the future.
But the meme can take form in other ways.
It is often used to decribe political, religious, and cultural ideals that feed into themselves and become a distortion of themselves over time.
it's possible that "Bad Wolf" not only turns into a representation of an idea where the words take on a different meaning, it can actually become more than that when a form of idea becomes a meaning of great cultural significance, and even possibly becoming a form of pseudo-religion in itself.
A belief system is a meme, and I think that this will be a key feature later on in the story.
The new UNIT fictional website warns of a file-sharing computer virus being accidentally downloaded from the internet.
An internet virus is also a form of a "meme". A meme by it's very nature is viral.
"All your base are belongs to us" is an example of an idea that becomes an internet phenomena.
Thus a form of Pseudo-religion can be formed.