Varo was previously involved in studies on the ecology, conservation and population genetics of tropical species. He studied the reproductive biology and feeding habits of characids, a family of subtropical and tropical freshwater fish. Varo made his move into genetics when he started his Master in Biological Sciences at the National University of Colombia in 2005. After completing his Master in population genetics, studying an endangered catfish from South American streams, he worked as a research assistant for the Conservation Genetics group from the same University. There, he made significant contributions to the understanding of the dynamics that have shaped the population genetics of one of the most important commercial, but also endangered, fish from Colombian rivers, Pseudoplatystoma fasciatum. He worked for two other Universities (Universidad de La Sabana and Universidad de La Salle), where he performed administrative tasks related to the evaluation and improvement of the quality in higher education (graduate and postgraduate academic programs). Varo joined Dr. Katja Nowick's group in March 2013. Now he is excited about embarking on the forthcoming research on the evolution of genes involved in the regulation of transcription. He aims to shed light on evolutionary processes affecting transcription factor genes within human populations, with some comparative analyses amongst non-human primates.