Inherent repeatable benefits of extraterrestrials
Lately I've been thinking about advanced life outside Earth from an evolutionary view. I've specifically been wondering what evolutionary traits are universally beneficial. If we were to find advanced life elsewhere, would they be anything like any life here? Is there an inherent advantage of, say, being either bipedal or quadrupedal? What about tails? Teeth? An organ for "higher functions" like the brain?
Obviously environment plays a staggeringly huge factor, and I wouldn't expect anything like the stereotypical little green men. I'm just wondering what traits are universal. What would be so useful as to make advanced life share it everywhere?