1. The only forms of life that we know about are on a planet with plentiful water and carbon dioxide.
2. Planetary dynamics may favor the production of such planets by the evaporation of gas giants.
Ergo, the rules of planetary dynamics appear to favor habitats for life as we know it.
This appearance may be just an artifact of our limited survey of life in the universe, but it's all we have.
As for the universe "favor"ing life, that doesn't really make sense either. I think it's safe to say the universe favors stars, gas giants, black holes but it's pretty hard to say the universe favors life when it's only given us ourselves as an example.
It's easy enough to imagine on Earth that conscious life never formed and to imagine such without changing the laws of physics. I don't understand anything about our universe that guarantees the existence of conscious life, let alone guarantees multiple instances.
All we can really say for certain is that our universe allows for us. We really don't know how rare we are.
Whether or not the universe favored life can be interpreted from the resulting improbability and the current results. Stars, gas giants, and black holes are probable.
We don't even know how life originated on Earth
I'm not saying these are necessarily plausible theories, but the fact that we can't discount them tells me enough about how likely we are to be able to calculate a probability for abiogenesis.
I agree that we can't know the exact means, just that abiogenesis happened, but we can still calculate the probability of our conditions needing to occur for abiogenesis to happen.
We already know that Earth as it is today can't support abiogenesis, since it's not happening, and judging from the phylogenetic tree, it probably hasn't happened for more than 3 billion years. There is also a reason to believe that even if the Earth was once appropriate for abiogenesis, it only happened once, given that all life on Earth shares the same chemistry (though of course it is possible that there was simply no other way for life to be, or that there have existed other forms of life from other abiogenesis events, but that they simply have not survived).
WAP: we're going to see selection bias in our universe because the preconditions for life must have been satisfied for us to exist within it.
SAP: all universes must satisfy the preconditions for life because cogito ergo sum -- the definition of existence requires life to perceive it.
I've probably sold SAP short because my own model of existence doesn't require perception, but clearly by this point we're well within the realm of philosophy.
Rather than cogito ergo sum, I think esse est percipi is the more appropriate phrase to use here.
esse est percipi: to be is to be perceived
The Weak Anthropic Principle from my understanding is simply that intelligent observers are possible. There's no implied likelihood or selection bias. Simply it's possible in our universe.
I'd agree with this framing.
As for the SAP, I personally find it somewhat meaningless. If that's how you define existence, then you're correct by definition.
If you believe a whole universe's existence requires perception to say it exists, I find that somewhat ridiculous. The universe came first and then came life.
Do things just pop into existence as we perceive them? And as we perceive more, does more stuff just pop into existence like all of the recently discovered lifeless exoplanets? Did those not exist until we spotted them?
I strongly believe trees fall in the forest and make sounds whether or not someone is there to hear. If you define a sound as having to be heard, then you're only correct through your own definition.
Because we of course do not exist in this universe because we're fine tuned to exist in it.
I can't think of a better way to describe it than the late Douglas Adams did :
“This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.”
The strong anthropic principle makes a statement about the fine tuning of the one and only, non-random, system that governs all systems.
I.e. the rudimentary physics & chemistry that happens to favours determine carbon based life generally.
If it were that there were parameters to tweak certainly many combinations would lead to degenerate solutions, but many that wouldn't and complexity would be found in many of them, some of it familiar, some beyond our imagination.
For mathematical dynamical systems (chaos theory) you'll find that you can tweak parameters. Some changes result in overall recognizable behavior, some changes result in completely different but still chaotic behavior, some changes result in boring, essentially empty solutions.
The universe is one big dynaimcal system; there's no reason to believe that if it is a function of certain chosen parameters, it is the only solution that would result in life.