Maybe we are late in the universe, perhaps universe used to be a lively and vibrant place homing millions of civilizations. Now, we stand as the last remnants, hence, possibly the most advanced.
Evolutionary biologist here. I think it’s highly unlikely.
It has taken about 4 billion years for intelligent life to have appeared on our planet (if you include the earth forming part), or 3.5 billion years (if you include when life first formed) to get our first “intelligent life.” By intelligent life here, I’m talking about technology in tool using and civilization building, to be clear. It’s a label I’d apply to our many of our ancestral and most closely related species. I believe much of life on earth is intelligent to the point of having things like theory of mind (the knowledge that one is a thinking individual interacting with other thinking individuals), including some birds and octopuses. The birds and octopuses part is important because it means that ToM evolved multiple times independently. That means that a) it’s a “good idea” (it has potentially significant adaptive value) and b) it’s possible to discover it along multiple pathways. Take eyes for example. Last time I looked, we believe eyes have evolved independently at least 24 times. They also exist at every stage of complexity and in a very wide variety of forms, and even something as as simple as being able to tell light from darkness has value.
However, in that 3.5 billion year history, intelligent life evolved exactly once, from a single line of descent. Intelligence such as ours is obviously a good idea. We went from being relatively unremarkable hominids to being the dominant life form on the planet, for better and for worse. Evolution is not moving all species to intelligence. Humans aren’t the point of evolution, any more than sharks or jellyfish are the point of evolution.
When such a manifestly good idea only evolves once, from a single line, the conclusion is that it’s pretty difficult to evolve. It might require a chain of preliminary mutations, or a particular environment. Being hominids, for example, we can make tools and carry fire, which dolphins and octopuses cannot. Of course, there are other hominids out there who do not do those things, and they’ve been around for millions of years. Depending on where you want to start the clock, they’ve been around for about ten times longer than modern humans - about 400k years, give or take. And the technology and civilization part has only been around for the last tenth of that, and has to evolve along its own, non-biological selection - and even those things differ wildly between different places and cultures. And even will all that, it’s become increasingly obvious that this might be a terminal mutation as the very drivers of our short term success may lead to our extinction.
I believe that extra-solar life probably exists. Whether it exists as bacterial mats or multicellular life, whether it’s discovered its own form of photosynthesis or has some other way of gathering life from its environment, whether it draws a distinction between its informational (eg, dna) and physical components - I have ideas but obviously no data.
In any case, that’s why I don’t believe that anyone has ever seen an extraterrestrial-origin ufo. I don’t believe the universe ever was nor will ever be teeming with civilizations.
All of that said, though, we’re dealing with an n of 1. We can make the best inferences possible based on what we can observe, but I would be delighted to be proven wrong tomorrow. I’m a sci fi nerd - I want there to be aliens. Even the discovery of a bacterial mat would revolutionize biology.
Would human intelligence be considered a possible evolutionary dead end? Dumb as a rock dinosaurs reigned for millions of years....modern humans have been her for 10k years and we are in the verge of destroying our planet and eliminating humans as a species.
We have mountains of evidence for alien craft flying around our atmosphere. The reason that “the aliens are nowhere to be found” is it’s just too terrifying to think there’s an advanced intelligence this close to us. It’s too much to deal with, so we ignore it.
To play a bit of Devil’s Advocate (from a bench-top scientific standpoint I come from immunology/microbiology background—so I know enough theory to be dangerous but don’t have your depth of evolutionary understanding) doesn’t a lot of this rely on cosmic timescales? I’m sure I could easily do a web search on this, but I think there are a lot of galaxy clusters that are much older than the Milky Way. That would give the potential for many multitudes of planets that have been around much longer than Earth, which gives a lot of time for intelligence to evolve and sustain. Now, if an intelligent civilization can ever survive for that long is a different question in and of itself.
I personally have wondered if the natural, sustainable, next step in any intelligent evolution is artificial forms of intelligence. Maybe biological intelligence is just the bootloader for less squishy forms of life? Immortal silicon life sort of renders the biological limits of space travel a lot less problematic. I know that comment exceeds the scientific into the philosophical, but it’s a thought I’ve had a lot lately.
I'll add that the sun is a 3rd generation star which are the stars that have planets with lots of heavy atoms like iron and other important to complex chemistry atoms. The sun is thought one of the eariler such stars.
Combine that with it being highly probable that light speed really is the upper limit for the universe. So we are among the first planets likely to be able to support life and and all the others are very far away.
So we are probably among the first batch of life in the galaxy and all the other life is likely very far away. It's not surprising we haven't seen any signs of it even though there is probably a fair amount of it out there.
I’ll also offer that a reason we’ve never seen a real alien UFO is simply the energy requirements limiting speed of travel through the universe (barring some undiscovered loophole in the laws of physics). To go fast takes lots of energy. To carry enough energy to accelerate takes even more energy. We haven’t even gotten to the slowing down part, the power consumption enroute, and recycling everything and replacing losses (atmosphere, parts, the steady and potentially catastrophic rocks and dust that will be encountered at speed, etc) for the duration of the journey. To cross any relatively minor distance would require decades at minimum if you’re in a star-dense area (now you’ve got to deal with radiation issues assuming the alien biology hadn’t worked out to survive that) to centuries.
You could probably get around that by sending robotic AI of some sort which would eliminate needing conventional life supporting systems, but you’d have to wait potentially centuries to get anything back depending on if you hoped to get a signal or a self-replicating ship to return data.
Yeah. Even if there was quite a bit of life the sheer difficulty of crossing distances in space and the energy requirements make it prohibitive.
Intelligence such as ours is obviously a good idea.
Is it though? And does an actual intelligent species destroy it's own habitat and make life harder for future generations? I'd think an intelligent species would do just the opposite. We're not intelligent, we're adaptable and clever.
I kind of close with that thought. A “good idea” in evolutionary biology is one that leads to reproductive success. Obviously, it’s possible to have so much reproductive success that you overrun the carrying capacity of your environment. That doesn’t happen as often when we’re looking at them in their natural environments - because species and environments co-evolve, and so each adaptation has time to be matched by other adaptations.
It’s always tempting to look backward through time and interpret a direct causal development from the bow and arrow to industrial manufacturing and spaceflight. But we can see by looking at all of the different societies and cultures around us that any particular path isn’t dictated by the human brain per se. The Yanomami and the Yoruba are populated with people exactly as intelligent as in any other human society. They are adaptable and clever, but never developed mass manufacturing or rocket technology. There are countless other civilizations that arose, gained a high degree of sophistication and power, and then disappeared while others have survived.
I do not believe in free will. That means I believe in strict causality. If you wanted to argue that the development of modern western political economies are a direct result of the Enlightenment, and the Enlightenment itself was a direct result of the world of ideas that came before it, you’d find a sympathetic ear (although I do believe that determinism is different from predictability, and that this complex system we call our society is more complex than any individual just as a human is more complex and less predictable than an ant).
In any case, it’s possible the “lethal mutation” that might lead to our demise (along with a good swath of the rest of life on earth) might have been a techno-cultural mutation rather than a biological one.
In any case, it’s possible the “lethal mutation” that might lead to our demise (along with a good swath of the rest of life on earth) might have been a techno-cultural mutation rather than a biological one.
Those are very good questions. First, I was distinguishing between multiple types of intelligence, rather than ranking them. However, there are several aspects of human intelligence that we’d probably be justified in saying something like “By these metrics, humans are more intelligent than any other species on the planet.” Those include the sophistication of technology, the amount and complexity of of information exchanged between persons, the ability to learn, and so on. Other animals can learn through accident or experimentation and adopt a new behavior. Some even exhibit social learning, as when a troop of baboons learned to wash their food by observing the matriarch, who had discovered it on her own. Most other species have languages, whether vocal, visual, or chemical. But most learning occurs over evolutionary time rather than at the individual level, and most of those languages are fairly hard coded.
The answer is definitely yes for the second question, with the eusocial animals like ants and bees being the obvious examples. The queen is not the “brain” of the colony. She is more like the reproductive organ. The brain emerges from of all the ants collectively interacting with each other and the environment. I agree with EO Wilson that humans are also eusocial, and so by extension carry out collective computation - information processing and learning - at the social level using what we might think of as an emergent brain layered on top of your individual brains.