Really? Different genders don't have different chromosomes, like in people? Or they have some cells of each gender, and temperature determines which survives?
Nile crocodiles have Temperature-dependent sex determination (TSD), which means the sex of their hatchlings is determined not by genetics, but by the average temperature during the middle third of their incubation period. If the temperature inside the nest is below 31.7 °C (89.1 °F), or above 34.5 °C (94.1 °F), the offspring will be female. Males can only be born if the temperature is within that narrow 5-degree range.
Giant-Size X-Men wasn't the first appearance of Wolverine. He'd appeared previously in an issue of The Incredible Hulk.In Giant-Size X-Men #1, the first appearance of Wolverine, his first statements are:
"Let them wait. It's good for the soul.
All right gents -- I'm here! Now who's this bigwig you want me to meet"
No problem.Whoops, should have said his first X-Men appearance, thanks XFanTim

Very cool info, Bubonic. (Well, cool to a science nerd like me.) I had no idea sex determination worked so differently in some animals.