 Until recently this was an extremely underdeveloped field in the philosophy of biology. This is surprising, because there is obvious potential for all three of the approaches to philosophy of biology discussed above. There is also a substantial body of philosophical work in environmental ethics, and answering the questions that arise there would require a critical examination of ecology and conservation biology (Brennan 2014). Over the last twenty years, this field has developed rapidly (Colyvan et. al. 2009).