Well, thanks for that, but I did read your entire comment and it was an honest question. Your third paragraph, for starters, includes a lot of "should" and handwaving.<p>In what ways were the starting conditions different?<p>Earth underwent radical changes in its environment in its early history. Did those changes -- from a methane to an oxygen-rich atmosphere for example -- result in radically different RNA or DNA sequences for the bacteria from each epoch?<p>Why should different starting conditions result in different forms of basic DNA anyway? Wouldn't the basic problems of evolutionary viability be the same?<p>There is indeed lots of stuff in Earth's base DNA catalog -- including some terrestrial critters that would do just fine on Mars, which would suggest that they could have independently evolved there. Tardigrades are one such popular example.<p>Your very last sentence is, "Truly independent life should have made at least some different decisions", but there's that word again: <i>should</i>. So, again: why?<p>On a completely different side note: this is part of the reason that anti-intellectualism is so rampant in America today. Those that have the combination of both ignorance and intellectual curiosity too often get met with sarcasm and indifference by people who then complain that nobody takes their opinion seriously.<p>So thanks for that.