On Thu, 27 Sep 2018 05:27:17 -0700 (PDT), Gary Harnagel
wrote:

I suspect that ALL life will have the same DNA.

That seems unlikely. We have created alternate forms of DNA in the
lab, using different bases than A, G, T, C, and U. And which code
differently. I can believe we might see similar genetic chemistry, but
many different bases and coding.

Some guesses are better than others. I think it's very arrogant to
believe that nobody's out there, and it's even more arrogant to believe
they haven't been around longer than we have.

Life, yes. Technological life, maybe no. We appear on the verge of
destroying ourselves, and that may be the norm for technological
species. They may not get much older than us.