A wide range of environmental factors can influence a developing embryo, and perhaps none more so than environmental sex determination. In humans, sex is determined by inheritance of highly stable sex chromosomes, where a female carries two X chromosomes, and a male a X and Y chromosome. In other species, how sex is determined can be far more complex, and involves intricate interactions between genes and the environment. For some, no sex chromosomes exist at all, and sex is determined solely by the environment, predominately temperature. Other systems are characterised by having sex chromosomes whose influence can be overridden causing sex reversal under certain conditions. In our research, we use the emerging vertebrate model species for environmental sex determination, to understand how an external cue can be sensed by the cell and transduced to genetic changes that ultimate direct sexual fate. In this species, the central bearded dragon, sex chromosomes (females have a Z and W chromosome, while males have two Z chromosomes), high incubation temperatures can override the masculinising influence of the ZZ genotype can cause male to female sex reversal. By manipulating this trait we have been able to uncover epigenetic mechanisms responsible for this change. most remarkably, these mechanisms are highly conserved, and in many instances are shared with humans. We have leveraged collaborations with biomedical research institutes to adapt techniques used in human and mouse research, for use in the dragon, which has yielded novel insights into the evolutionary conservation of epigenetic mechanisms.