Ridley Scott: Aliens exist and they will come for us ....

Is there life out there? Chances are pretty high, given it evolved here. However, for most of the planet's existence life here was very basic(much of it still is even today. Consider that you reading this has a body half made up of "you" and half made up of bacteria). Then we had a set of circumstances that kicked off more complex life(Cambrian big freeze one suspect), then it got all sorts of complex, crawled out on land and looked to be going in a certain way. Then the Permian extinction, about the worst in Earth's history, killed damned near everything in sight, wiping out millions of species. Another reset, then the trajectory of life kicked off again with the survivors only for a meteorite to come in and kick off another mass extinction event and say bye bye to the dinosaurs(and many others). then the age of mammals and so forth and then various apes, that initially sprung up in a tiny area, diversified and ultimately led to us. There are a lot of what if's in our evolution. Maybe another creature could have become something like us? There were many bipedal dinosaurs, with grasping hands, quite large brains(their relatives birds can be extremely bright with apparently small enough brains). Maybe one of them might have gone down the road of intelligence as a survival "trick"?

Though this brings us around to another point illustrated in C's great post:

Calibos wrote: »

Convergent evolution probably means that the requirements for intelligence to arise are the same everywhere and evolution will arrive at similar solutions. Intelligence requires lots of calories for the brain so will likely only arise in predators. Predators invariably have binocular vision, Binocular vision is required for depth perception and manipulating the world. Freeing up some appendages to more easily manipulate the world. ie. Convergent evolution likely means that most of not all intelligent life is bipedal with two eyes and at least two arms.

Quite likely C(if the environment is broadly similar), but it raises another question for me, one that has interested me for a while. As you say convergent evolution tends to bring forth extremely similar responses to evolutionary pressures. So lots of very unrelated different animals living in water evolve a "fish" shape. Fishes themselves, sharks, dinosaurs, dolphins. Flight impacts similarly, to give us "flying things" of unrelated species.

And all of these convergent adaptations have occurred many times in many species throughout the story of life on Earth, save for one; intelligence*. That particular adaptation seems to be very very rarely positively selected for and requires a particular set of narrow circumstances for it to kick off. That particular adaptation has only kicked off the once, in broadly one place, in one narrow set of species, the great apes. Even within that group only one line went full brainiac. Even within that one line that started to grow huge brains and diversify, only one among them evolved a particular intelligence like ours. Humans with big brains have been around for at least half a million years, 100,000 years ago there were a few out there alongside us. They might have been a resourceful intelligent group of peoples, but we were different. That difference was subtle at first but it grew and grew until a point was reached where we sailed off far away into the distance and they faded out.

Take one massive "killer app"; symbolic culture. A couple of square metres of say a French cave that we inhabited will throw up more cultural artefacts than the entire history of such artefacts(most of which are debatable) of all the humans that preceded us, anywhere in the world.

Oh and BTW, to all those "religion is mindless nonsense" folks out there, consider this; it may be increasingly irrelevant today, but it was one of the main driving forces of modern human's becoming modern humans. It was our first attempt to divine(no pun. Well..) the fabric of reality around us, to divine ourselves and our relationship to that reality and that need to know is what ultimately gave us science and post Enlightenment rational thinking and got us to where we are today. One day we may become gods in our power and understanding, we may even create new universes in the lab and when that day comes, we will have that human need and expectation that gods could exist to thank for it.

So imagine another "Earth" that somehow got to the point where big brains were selected for and gave rise to "apemen", but for some reason our particular kind of intelligence never took off. And it may well not have. Our ancestors did very well, for a very very long time without going full Sapiens. If we landed there we'd see small groups of resourceful cavemen, but no cities and advanced tech. If such cavemen ever took off in the first place...

As for aliens? I'd reckon that any species that got to our level, understood the workings of evolution itself and started to tinker with it, would sooner or later do something no other creature could even dream of doing. That is engineer our own descendants, our replacements. I suspect that if we do find aliens, or they come to us, they will be what we might term AI type species. One that long left their naturally evolved bodies behind. This would also solve the distance problem. Travel time means little to an immortal species that can hibernate in between the interesting bits.

Might they be warlike such as Hawking suggests? We simply can't know and he most certainly doesn't(he's an OK physicist, but beyond that his opinions carry about as much weight as any other halfway intelligent public talking head). We as biological creatures with the veneer of mind overlaying our all too finite body have very anthropocentric mindsets. AI type creatures would have very different mindsets and needs. Maybe information is what the get the horn for. Who knows. Though they might wipe us out as a byproduct of not really seeing us, much as we might kick over an ants nest by mistake. It wouldn't be personal.





*before the cries of "other animals have intelligence!" Yes some do. But none come close to the suite of features and sheer brainpower of humans. Yes, other animals can use tools for example, once thought to be our preserve, but show me another creature that makes a tool to make other tools.