i suppose, but this perspective also comes with its own anthro-centric assumptions.
For example, the assumption that we are the most intelligent creature to have yet emerged from the evolutionary process is most certainly a function of how one measures "intelligence". it might be the case that one can measure intelligence through the fossil record, but i would be interested to see a study of the selective pressure that produces advanced and intricate central nervous systems, and to understand how this could be said to increase in overall terms. i think it might not be the case, although it might, given certain selective conditions. i'm not sure we know what those are.
To me, the definition of intelligence is to produce the most appropriate response given the circumstances. So a plant that turns its leaves towards the sun is displaying intelligence. are plants more intelligent than we? by some measures yes - being able to respond to direct sunlight by producing energy is certainly appropriate in some circumstances - plants have solved a problem that we cannot, and therefore are more intelligent than we. (and i know folks will reject the idea that photosynthesis is a form of intelligence, but in my opinion that's anthro-centrism!)
is pondering the orbits of distant planets the most intelligent activity to have been performed by any organism ever? is building mega-cities and particle colliders? We don't know yet. it could be extremely inappropriate, because it could be next to impossible to travel between stars, given the reality of our existence. we could be leading ourselves to our own extinction, by dramatically altering our own planetary biosphere and chemistry, in pursuit of lofty visions such as interstellar travel. That's not so intelligent.
Another relevant point is that we don't have very much of the fossil record. i read somewhere that we had like 4% or so, although i am not exactly sure how one estimates that percentage. But assuming so, somewhere in that 96% there could be critters more freakishly intelligent that we.
suppose that in the 4-5 billion years of life on earth, of which our own record of relatively extreme intelligence is only 2,000 years old, there could in fact have been civilizations created by social creatures with as much or more intelligence than we. There could have been cities, perhaps in the millions and millions of years when dinosaurs were common. Granted this goes against commonly held assumptions, but it is certainly not impossible.
Keep in mind, a mere 150 years ago, we had a global civilization that could have vanished easily without a trace in 20,000 years, let alone 1 million. do we think of ourselves as incredibly more intelligent than our great grandparents, or theirs, or than people living 300 years ago? Better informed on certain topics for sure, but more intelligent? We are more like plants now, in that our intelligence is specialized to certain techno-powerful purposed, of which the intelligence relative to our external conditions is still yet to be decided. We might say that our ancestors were more intelligent for avoiding the kinds of environmental and social disasters that we have engendered.
Anyway, were we to go extinct now, we assume that future intelligent creatures would find remains of our great civilization. But we don't know how long these would last. There's some luck involved. it's possible that the hominid layer could degrade quickly!
On the other hand, if common assumption is correct and we really are the only potentially starfaring organisms to have evolved yet, then that argues my original point that life, and life worth communicating with, could be exceedingly rare. in 4 billion years (about 1/4th to 1/3rd of the age of the universe) life sufficiently intelligent to travel the stars has only emerged once. Those odds seem low, but they might be freakishly, abysmally low as well. Had it emerged twice, and we had some evidnce, odds would be better, but once! That's hard to quantify, especially as the longer life persists, the more likely it is to be wiped out by some kind of extinction event.