One thing I have been mulling over since the seminar is the question of morality. I need to start with an apparent diversion, but I hope it makes sense by the end.

Biologically, there are basically two main strategies to leaving descendants. The first, (e.g. mammalian and avian) is to have a very small number of offspring and spend a lot of effort nurturing them and the second (many fish and insects, all vegetation as far as I know) is to have a very large number of offspring and little or no nurturing.

I see big obstacles to the second approach developing any kind of technology because I don't see how information can be passed between generations easily in that approach, but I accept that could just be lack of imagination on my part, so let assume an intelligence capable of technology can develop under that reproductive style. I say this not because technology is essential to intelligent life, but because the only approaches we have been able to think of for detecting alien life so far - again as far as I am aware - rely on them having technology. Either that they visit us, which needs them to have technology we don't have, or they developed a means to send information via the electromagnetic spectrum far enough in the past for it to reach us when our technology is capable of detecting it.

Which brings us to moral systems. At the heart of ours is a protection of life: directly with prohibitions of murder, or indirectly with prohibitions of theft for example. But a creature with a different approach to descendants could, I suggest, put a completely different valuation on life and so have a well developed system of morality utterly different to our own.