Evidence for second genesis of life and the Guardian of Forever

Welcome! "Alien Life" tracks the latest discoveries and thoughts in the various elements of the famous Drake Equation. You may notice that this and future entries are shorter than usual; career, family and book deal commitments have forced me to cut back some of my projects. Now, here's today's news:
g Abodes - Gazing into the majestic Grand Canyon, awe-struck visitors inevitably ask: "How old is it?" Far older than generally thought, says new evidence that scientists culled from caves lining the canyon's red limestone cliffs. See article.
g Life - The view that life will emerge with high probability on Earth-like planets is shared by many scientists, although opinions differ on just how like Earth an Earth-like planet needs to be. One planet known to be 100 percent Earth-like is Earth itself. If life originated on Earth, rather than being brought here from somewhere else, the question then arises as to whether life may have arisen more than once. If that is the case, then it is of interest to ask what evidence might exist for such a second genesis of life. See article.
g Cosmicus - South Korea said Monday a female engineer would become the country's first person in space by going aboard a Russian spacecraft, after Moscow rejected Seoul's first choice because he violated reading rules during training. See article.
g Imagining - Could Star Trek's Guardian of Forever — the ancient portal that does not know if it's a machine or a life form evolve? The Guardian likely is an intelligent, self-aware machine. Presuming that time travel to the past is even possible, the enormous energy required to accomplish this task likely wouldn't arise in a naturally evolving organic creature. Instead, it probably would be done mechanically (though organic elements might be incorporated into the machine's components). Of course, a significant motif of science fiction is the question if artificial constructs that gain self-awareness then also "life" (as in The Next Generation android Data). A civilization capable of creating a stable time portal almost certainly also would be capable of creating an intelligent, self-aware machine. In short, the Guardian didn't evolve via survival of the fittest but was built.
g Aftermath - Here's another "old" piece worth reading: "Consequences of Success in SETI: Lessons from the History of Science" given during a Bioastronomy Symposium in 1993.