May Earth have received seeds of life by "Directed Panspermia", because the senders knew that Earth belonged to a sun system with stable Titius-Bode structure?
Assume that our human civilization would want to bring seeds of terrestrial life to other planets in other sun systems. Limited resources would bring up a fundamental question for such an endeavour: Which stars / sun-systems were the most promising targets?
Possible criteria for candidate sun systems are:
(i) Distance of the system from earth;
(ii) Number of planets in the system (should be at least one);
(iii) Dynamic (longterm) stability of the system;
(iv) High probability for planet(s) in the habitable zone around the star.
(**) Concerning (iii) and (iv), systems with non-eccentric planet orbits and "regular" distances (for instance given by some sort of Titius-Bode Law) might be interesting candidates.
For explanation: The Law of Titius-Bode says that in our sun system distances between planets and the sun are well described by the formula
4 + (3*(2 to the power n))
where n runs through minus infinity, 0, 1, 2, ... .
Now, I turn things around and speculate that life on earth may have started by the successful execution of an analogous "directed panspermia" project of another extraterrestrial intelligent civilization with similar paths of thinking - especially along (iii), (iv), and (**). Then it would be not a surprise that our solar system obeys a Titius-Bode structure.
Once more in short: Earth may have got seeds of life in some scenario of "directed panspermia", because the senders knew that Earth belonged to a sun system with stable Titius-Bode structure.