No planet is more earth-like than Earth itself, so if life really does pop up readily in earth-like conditions, then surely it should have arisen many times right here on our home planet? And how do we know it didn't? The truth is, nobody has looked.
“Take motherhood: nobody ever thought of putting it on a moral pedestal until some brash feminists pointed out, about a century ago, that the pay is lousy and the career ladder nonexistent.”