A population of green sea turtles is turning almost entirely female due to changes in the environment, temperature changes at the Great Barrier Reef made male turtles change their sex. The transformation has led scientists to be concerned about the species’ future as there are only 0.2% of turtles who remained male, and it makes turtles unable to reproduce. The proportion of female hatchlings increases when nests are in warmer sands, while cooler temperatures are more comfortable for males. The ‘pivotal temperature’ that creates a 50/50 split of male and female can be passed down from parent to offspring. Genetic and hormone analysis of the turtles in the northern and southern parts of the Great Barrier Reef showed 99 percent of young sea turtles nesting on warmer northern beaches were female.