Not necessarily. As Wikipedia says, "According to the Great Filter hypothesis at least one of these steps - if the list were complete - must be improbable." That is, if "Great Filter" means anything, it's that one or more of the steps to achieving a technological civilization that can expand throughout the galaxy is very difficult ("improbable").
What I'm talking about goes like this: suppose that none of the steps are very difficult. Of course, that doesn't mean they're instantaneous - each step takes time. You need elements other than hydrogen and helium for life, so you have to watch the supernova clock ticking until Population I stars form (maybe Pop II, but remember that this is hypothetical - let's assume that only Pop I stars have enough "metals"). Then you need planets - but we're seeing planets everywhere as the limits of our vision increase. Once the first replicator forms, you have to wait for evolution to grind its way up the complexity ladder (mandatory disclaimer: evolution doesn't "prefer" higher complexity, but there is a complexity lower bound - there is literally nowhere to go but up). In this scenario, where none of the steps are improbable, but they do take time, what would the first intelligent species in a given lightcone see?
They would arrive on the scene, and they would see a young-looking universe. Their star would be among the first stars capable of supporting life. Their planetary formation would have been almost immediately followed by the first replicator (and returning to reality for a moment, we see fossilized life as far back as 1 billion years after the Earth's formation). Their evolutionary history, while marked by giant impacts and mass extinctions, would appear relatively free of long reigns of nothing happening complexity-wise. And they would see an empty universe, and wonder where everyone else is.
Obviously, I don't know the answer to the Fermi Paradox. But if anyone exists, someone's got to be first. Maybe it's us, and maybe that's why the paradox is so baffling.
(Instead of "where are they", I think the LW way of phrasing the paradox is "why aren't we paperclips?".)
That's a very attractive scenario. But I don't think 'Someone had to be the first' is sufficient to explain why we are the first. On your view, intelligent life takes some time to get going, but then is incredibly abundant for as long as stars and metals abound. On standard cosmological models, star formation will continue for some 100,000 billion years (or at minimum 1,000 billion years). Anthropically, our occurring only 14 billion years into our universe's lifetime is then profoundly surprising. If a lot of intelligent life precedes us (and/or intellige...
One serious issue for evaluating existential risk is working out whether most of the Great Filter is behind us or in front of us. This relates to the Drake Equation and similar attempts to estimate the frequency of life in an obvious way.
Over the last few years, it has become increasingly apparent that extrasolar planets are common. However, what fraction of these planets lie in their stars habitable zone has still been an open question, primarily because most of our current methods for planet finding easily find planets that are either very large or are very close to their star (ideally both).
A new study, using the data from the Kepler spacecraft, estimates that about a third of all stars similar to the sun have at least one planet in the habitable zone. There are some issues with this estimate, and Phil Plait discusses them at his blog. The estimate has a large amount of variance. The paper actually estimates 34% +/- 14% and the issues that Phil brings up increases the uncertainty in both directions but it seems safe at this point to consider this not being very far off.
One obvious issue from a Fermi perspective is that some systems will likely have multiple planets in this zone. Also, having planets in the habitable zone is clearly not sufficient for life. By the standard estimates for habitable zones, Venus and Mars are both in the habitable zone of the sun. And there may very well be ways for life to arise outside the habitable zone. Moons like Europa and Titan seem to be excellent candidates, and we can't rule out more exotic forms of life in other habitats although that seems not too likely right now.
However, one thing this makes clear: The part of the Great Filter that is behind us that is due to planets not lying inside the habitable zone is small. So the question is, what does this mean for our estimates of how much of the Filter is behind us and how much is in front of us?