In nature, certain animal sexes (male or female) are determined by the temperature of their surroundings during a critical time in their development. This thermosensitive period occurs after the egg has been laid. So sex is at the mercy of the ambient temperature of their surroundings. For example, in turtle species eggs from cooler nests all develop into males, whereas higher temperature nests result in females. In terms of what you learned in the unit, explain this phenomenon.