I liked the paper. It helps put into perspective some implied necessary conditions to evolve "radio telescope" making lifeforms. I've thought about octopi before as they seemed to have the necessary agility and intelligence to get there. However, their basic reproductive behavior of generating thousands of offspring and then dying immediately after a short lifespan seems to constrain their ability to evolve further.

I wonder if octopi were genetically modified to live longer, live after mating, and to have few offspring if they would naturally evolve culture and higher level intelligence? It is curious and a valid point, that out of all the oceans, no human comparable life (culture transmitted symbolically) had ever evolved. That might imply that it is unlikely to find intelligences on ocean worlds. There is some set of environmental conditions that precludes finding the right mix of traits to get to human-equiv intelligence level. Dolphins are intelligent and social, but they are designed to be so efficient in the water they hydrodynamically selected against tool making hands.

What are the conditions to create culture (which is necessary for a radio telescope)? Some necessary conditions might be:

predisposition for social interaction and cooperation
ability to make complex tools (hands)
ability to reason symbolically (and communicate that way)
few offspring
minimum lifespan of say 35 years
competitive generalists (adaptive to complex environments)
successful enough before culture to build up relatively high density

A lot of his points can be counterargued (by our one example) by making use of the "niche" argument. That basically life fills all the environmental niches. As it so happens intelligent culture might be able to only evolve in a line in a certain environmental niche. Since primates may be the only species that filled the "dexterous hand, big brained, few offspring" niche, that might be the only viable line for creating "human-like cultural" intelligence. A positive point for this argument is that there were a number of extinct species that evolved in this lineage. We will probably have a chance to explore some of the key issues in this evolutionary trail through genetic engineering and analysis. Will it be possible engineer chimps to be capable of higher level culture? What about octopi?! The reproductive aspect of octopi may be too basic to overcome.

I believe all life derived from chemical soups will have all the basic game theoretic strategies for optimizing evolution embeded into its "dna". That is because of the chemical warfare that will have gone up for billions of generations in the soup. So, the impetus to evolve and use strategies to get to intelligent life will be there. However, the chances of having the right environmental conditions and probability of getting all the right traits and mutations together to get to "human-like" culture is certainly an open question. The first time I put in my guestimates into the Drake equation I got a probability of 1 intelligent species per galaxy. Maybe I wasn't that far off.

I certainly don't doubt there is a lot of "basic" life around however. Getting from there to intelligent life I think is a lot more mysterious.