The turtles were pretty clever... I hope

I've read in one review that it was a metaphor for the slow pace of change, and that the Cardinal had pushed that one ahead, hastening its progress. Which certainly could be seen to accord with the main theme of the film. Maybe a little hammy, or whack-you-on-the-head-with-the-message, though.

That's a good point, though - I think in many reptile species sex is determined by the temperature in their nests. i.e. somewhat fluid, less rigidly 'fixed'.

I thought they were supposed to represent the cardinals, being slow, old and apt to get into trouble when let outside the walls of the Vatican. When Lawrence scoops one up towards the end and places it somewhere safe, I thought that represented him looking after the new pope.

I thought it was supposed to represent that African refugees are migrating into Italy?

;)