Merged from the "Do you think we are alone in the Milky Way?" topic
midtskogen wrote:Source of the post Or not. One can argue that the K-T event was the start of the age of mammals, and here we are. Whether it was necessary that the dinosaurs went away for something like us to evolve is certainly debatable, and so is what the outcome of evolution would be if there had been no K-T event, but without it, life on Earth would certainly be very different.
Yes, I remember reading a paleontology paper a while back which stated that the lineage leading to the rise of the Great Apes was ALREADY present during the Late Cretaceous, and that primates would have evolved more or less along the same timelines as they did without the dinosaurs. But it is really hard to say for sure, because alot of other climatological factors effected primate evolution.
A-L-E-X wrote:Source of the post but our galaxy is huge and we are a very rural part of the galaxy,
I don't think so. There is such a concept known as galactic habitability zones, and the region our sun inhabites lies square in the center of it. It orbits between highly active spiral arms and does not swing too close to the dangerous galactic nuclei regions. Furthermore, Sol wasn't formed too far out into the metal-poor outer regions wherein terrestrial planets might be rarer in solar-systems. Like all habitable zones, there are exceptions and particularily exotic or highly technological life may exist everywhere - but populations of naturally-occuring organic life should be denser in galactic regions similar to the one our sun currently inhabits .