In the past I've explained that the likely possibility is that we are one of a few species evolved sufficiently in intelligence to be able to ponder and soon engage the task of physically leaving our solar system. A great filter exists which has made it incredibly difficult for life forms to evolve to our present level until this time in galactic history. This idea mirrors the Universal concept of anthropomorphism which states that we exist at all because if the Universal constants were any different we simply wouldn't and that there is no actual "fine tuning" to the Universe. I propose the same is true about Galactic evolution and that we may be among the first set of civilizations that have survived long enough to actually figure out ways to leave our home planet. Later, I proposed the idea of a Fermi Silence as a means of explaining why any of the current civilizations in the galaxy that may be at our level may not be aware of one another potentially due to the differing nature of their communications technologies.
Yet here we are steeped in silence, the results of the Kepler Exoplanet survey has provided us an embarrassment of riches in terms of data on the likely percentages and types of systems that exist in our galaxy and the results show clearly that there are likely hundreds of billions of planets that are suitable to support our kind of life forms...not just human life forms but various forms of life.
The interesting question of evolution of life in the Galaxy often assumes that different systems would likely emerge and evolve life forms along convergent traits but this assumes that the probability of starting life is high enough that across a couple hundred billion experiments more than one positive outcome could emerge....even with 13 billion years of trial time across systems in the Galaxy. What if this is it and we are indeed the first system with any complex life above bacteria??
There is no reason to think that once we can perform interstellar travel that we would be doing so as "human 1.0" especially given the radical advances we have achieved just in the last few years of being able to fundamentally adjust our biology to suit our desires. The recent invention of technologies for in vivo genetic modification (CrispR- Cas9) will be more than just a boon for cosmetic and genetic repair...they will also allow targeted upgrades to our physiology. I told some hypothetical stories along these lines in my articles on the life of Afusa O'Reilly, but Afusa being a super mortal is still fundamentally human...what happens when we upgrade the genetics of other animals?
A recent article proposes this as an ethical question but when we are out exploring the galaxy a likely strategy for ensuring that life (regardless of type) persists would be to engineer from all of the animal kingdom super intelligent strains that may find a larger percentage of discovered exoplanet viable and leave them to seed the planet with "dna" baring life even if it isn't human life.
One could imagine what would result in deep time as evolution continues to evolve these seeded species across the spectrum of animal forms on these far flung systems? They may end up evolving into locally adapted and superior species, they will become dominant species and may if they avoid the same mistakes as we will also emerge technology and leave their systems to discover life out there...only to find that there is a common origin...by then lost to time, our original species long evolved away to other forms or entirely extinct....yet our gift to populate the Galaxy with varied forms of intelligent animals that evolved into superior intelligence replaying the cycle of our search Eons before.
I find this idea that we, humanity are the pioneers of the spread of life in a trans planetary exo spermia of our constitutive elements...not unlike what was used as a premise in the recent Alien prequel "Prometheus". Are we the first "Engineers" of our galaxy?