From melting ice caps to fish migrating to find cooler water, climate change has a great deal more impact on the world than just raising temperatures. Researchers at the University of Canberra in Australia have discovered another way climate change impacts the world: it is changing the sex of bearded dragons.
For some time now, Drs. Clare Holleley and Arthur Georges have known that male bearded dragons are capable of switching sexes if it gets hot enough. They had observed this in the laboratory, and noted that, under extreme temperatures, genetically make dragons were turned into females. Although, chromosomally, they were still “male,” they were fertile and often laid more eggs than chromosomally female dragons.
Recently, the researchers completed a study using data from 131 bearded dragons in the wild as well as controlled breeding experiments. They found that, by breeding the newly female dragons with male dragons, they could establish breeding lines in which sex was determined by temperature alone.
Considering that the chromosomally male female dragons tend to lay more eggs, warmer temperatures could end up being a boon for the bearded dragon, though it poses some important questions. Namely, what can such changes tell us about evolution? Sex determination has a profound impact on the evolution of creatures that reproduce sexually. Maintaining a sexual balance that allows the species to continue, while preserving the strongest gene pool, is essential.
It also stands to reason that, if this change is possible in bearded dragons, it is possible in other species as well. A deeper understanding of this change could help us to better understand, and predict, how climate change will impact evolution. Species are constantly evolving to adapt to changes in their environment, with certain species proving more adaptable than others. If certain species end up breeding at higher levels thanks to climate change, while others see a reduction in population, we could see real problems for biodiversity.