this blog post the other day, "Why we'll never meet aliens." I'm familiar with the Fermi Paradox (if there are smart aliens, where are they?). There are a lot of assumptions built into that question, and a lot of possible explanations. But as imaginative as humans are (or imagine themselves to be), it's hard to get around the sample size problem. Everything we know about how intelligent creatures can be expected to behave is based on observing ourselves. If you expand that to other Earth life forms that are intelligent (other apes, whales, crows, etc.) or even just "interesting," you can certainly expand the range of possible adaptations (hive behavior, long lifetimes, different types of senses, metamorphosis, etc.). But all of these life forms evolved on this planet, and only one of them is known to possess the means to communicate or travel across space, or even to be curious about worlds other than this one. That is us. Are us. Sample size, N=1 for my purposes here.
One of the functions of science fiction is to go beyond that limited view, to imagine very different forms of life, intelligence, culture, and technology. There are zillions of examples of this, from the abysmal to the sublime. In "popular" SF (I'm thinking of most SF movies), writers tend to stay pretty close to human forms or at least motivations. This makes it easier to understand the story in terms of good guys and bad guys. Sometimes the bad guys (mysterious aliens) do pretty dumb things, like coming to Earth to take our water, because they need hydrogen (dudes, hang a right at Mars and check out Jupiter). That's one of the arguments of the "never meet aliens" blog post I found. They don't need us! They've got faster than light travel and they know where to find hydrogen (and anti-hydrogen) if they need some. They've been scooting through wormholes for millions of years, and they've seen all the possible forms of life. Humans? Yawn.
I mostly buy that. By the principle of mediocrity, our star and planet are nothing special (we've recently identified hundreds of planets orbiting other stars). We don't know how easily life starts (N=1 again), but we probably aren't very special in that regard either (although life had to emerge first SOMEWHERE in the universe, and it could be that we are that special - there's no way to know right now - just like someone wins the lottery, just never you). So I agree, it doesn't appear that we have much to offer an advanced alien life form.
Or do we? What is likely to be interesting or valuable to really old, advanced, intelligent entities? Maybe information. We have a lot of that here. Not so much in our computers and networks (though it's getting there), but rather in all the genetic material for all the millions of lifeforms on this planet. Although there may be similar beings elsewhere (filling similar ecological niches, much the way wolf-like creatures evolved independently in Australia - they happen to be marsupial and extinct, but OK), there is likely to be no life form elsewhere with exactly the same genetic signature as any particular species here on Earth. Evolution is a very big, parallel processing computer program that has been running for millions of years and generating millions of locally optimized solutions to the problem of living in some part of this world. The solutions (and programs) are recorded on tiny "reels of tape" called DNA.
That's the basic idea of a great SF trilogy I read in the last few days, Lilith's Brood (which collects all three original books) by Octavia Butler, although it's a lot more interesting than I've made it sound so far! Written in the late 1980's, it starts with a nuclear war on Earth that very nearly wipes out humanity. But it turns out that a race of life-craving and life-preserving aliens have been studying us for some time from gigantic spaceships lurking in our stellar neighborhood, and they come in and rescue and heal a large number of surviving humans. Why? For a captive breeding program, basically. Wait, no, it's not what you think! Mars Needs Women, right? Vonnegut's zoo on Tralfamadore? No, it's not like that, but in a way it is, and that's what makes these books so confusing and engaging.
This blog post is already longer than I intended, so I won't attempt to summarize or review the books in detail. Some consider them to be an allegory on colonialism and slavery. I can see that, but I thought they were more about what it means to be alive, to be "a people," and what it is that is valuable about life, any life. And why anything would "want" to live. While there is plenty of incidental technology (most of it could be considered extreme genetic engineering), that is not the main point. The Oankali have starships (organically grown!) but there is no discussion of their propulsion or the nature of space-time. Almost all of the book is about interpersonal relationships.
The Oankali are natural genetic engineers who can sense and manipulate genetic material as easy as you and I use a fork and knife. They crave new life forms, and they engage in genetic "trade" - integrating novel genetic "programs" into their own bodies to drive their own evolution (human cancer was a real find, like a fancy power tool if you learn how to harness its power, as they quickly do). They don't intentionally destroy life - unless you consider hijacking your reproductive system for the purpose of creating hybrid or "construct" children to be "destroying life." They certainly destroy "life as we know it," but humans would have become extinct if the Oankali had not come along. The Oankali value, preserve, and extend life, but they do not value any particular form of life. Their people have "traded genes" with many planets' species, and in so doing have changed their physical nature completely. While they will incorporate human DNA and adopt some human characteristics in the process, it is not in their "charter" to preserve the the culture or other defining characteristics of humans and human society. This is where the colonial and slave trade parallels really come to the fore - although the Oankali don't label the humans as "primitive" as Europeans once labeled native people they conquered (all genetic information is potentially useful!), neither do they honor or preserve most of the things humans consider important.
It sounds weird, I know, but the writing and characters are really wonderful. I still don't really know what I think about all of it. But I do believe that if there is any reason for other intelligent beings to be interested in us, it could be in the immense complexity and diversity of DNA that is within the genes of every plant and animal on Earth, including us. They can fill their hydrogen tanks at the nearest gas giant before they drop by here.