Evolution off Earth is not evolution

 “Supra-Darwinian” life, [may have] arose by pathways that don’t exist on Earth.

For instance, say we find a planet full of aliens who have achieved immortality. The population has been stable for thousands of years, with nobody being born and nobody dying — in other words, there is no self-replication going on. There is no variation. Everything is static. There’s no evolution. Would this alien species be considered living under our current definition? And should it be? Of course, this is a wild theoretical, but as we learn more about the immense universe, this kind of questioning will be important to consider.

Another problem is that even though we have a huge diversity of life on our planet, we might only ever be able to trace life back to a single origin. A single random accumulation of events resulted in that first cell or that first organism. But research has acknowledged that there are many alternative biochemistries and biologies that could have arisen from the conditions on early Earth. The world would probably look a lot different if, for example, silicon were the basis for all organic compounds instead of carbon, a theoretical possibility.

Yet all the tests that we currently use to find life on other planets strictly take our carbon-based system as the norm. For instance, in 1976 when the Viking I first landed on Mars, it was rigged with only a few kinds of tools to probe for life on the red planet. One was a radioactively-labeled carbon species, 14C, that the robot mixed with a small sample of Martian dirt. Researchers speculated that if there was life on Mars, the life would metabolize the radio-labeled species and produce radio-labeled carbon dioxide, the way Earth life forms would. This didn’t work. It probably didn’t work because there isn’t life on Mars. But it also could have been because we were specifically testing for life that metabolized carbon just as life on Earth does.

From: https://massivesci.com/articles/definition-of-life-earth-universe-virus/ http://ufocon.blogspot.com – The UFO Iconoclast(s)