Evolution always seeks to create a population such that its goal is the proliferation of that species in the short term (in evolutionary terms) with no regard for the future.
Moral conscience is only beneficial to a species when the species exists globally such that there are little or no free resources. Only then is the greater good more beneficial to the survival of the species than the individual or the good of the pack/tribe over another pack/tribe.
However on the flip side intellectual evolution is an advantage even in very sparse populations with plentiful resources. Greater intelligence means you can harvest and utilize those resources more quickly and put them to use growing your family or tribe as well as defending it.
As such due to the nature of evolution moral evolution is doomed to always lag considerably behind intelligent evolution. Furthermore since evolution is, in human life span terms, a very slow process, it isnt something that should be expected to catch up until many generations, and a lot of death has passed first. Due to the nature of intelligence to enable us to find more effective ways of killing ourselves this can inevitably lead to a species destroying itself long before its moral evolution has a chance to balance the equation.
It is this reason that many scientists speculate why we dont see very many radio signals in space indicating alien intelligent life, the theory goes that the very nature of evolution is such that life will almost inevitably destroy itself once it reaches the intellectual singularity before it has a chance to become interstellar and as such simply doesn't have a very long time span where it exists in a state where it gives off radio waves.
Sadly we dont appear as though we are going to be much different in that regard.
@freemo there are alternatives: ET occupies a world in which EM radiation never developed as a useful means of communication, hence no observables. low natural birth rate + lack of interspecies competition + strong cooperative biases make ET less violent (IOW space bononos)
@freemo whale-like species in a world ocean communicating through low frequency vibrations. planetary network of intelligent plants communicating by RNA-coded messages through their roots.
anyway, maybe there's no need for long distance communication for ET: they all live in a small enough region of their planet that they don't need long-range
@2ck Whale-like species are not intellectually advanced, if they were they wouldnt be communication through low-frequency vibrations alone and would employ EM.
Low frequency ocean communication is far inferior to EM for several reasons.
1) it has extremely low temporal resolution. Therefore can only communicate very small amounts of information. Nothing even approaching reasonable data rates for communication could be achieved
2) it only works when the ocean conditions are just right. Most of the time at any given moment a whale is completely unable to communicate globally using this method. It is only when conditions are just right that global windows open up.
Etcetera.
The other idea of chemical communication through roots would likewise be limited in all likelihood. It would effectively be a chemical mesh network which current theory already tells us can not work in global, public, high speed, communications network due to some fundamental limitations.
As for not needing global communication. Sure that could work for a species. But would be invalid if we are talking about any species capable of interstellar travel, or even travel across their own planet. Which is exactly the type of species we are talking about.
@freemo you never said we're talking interstellar. are you assuming that any other intelligent life would have been observed by us by now?
The main argument of the OP is that life never reaches the point of their evolution to become interstellar, or to give off much in the way of EM we can detect in general, because the time between a species advances enough to both need and utilize EM is shortly before the point a species is advanced enough that it kills itself off as well.
@2ck Because EM waves move at light speed and there is no form of communication equally as useful that would be accessible to most developing species.
How else would you propose they communicate long distance that wouldnt be far beyond the initial levels of science a species would develop?