He and his team have designed and implemented a three-pronged strategy where research, environmental education, and conservation actions feed back into each other and contribute to the development of activities in his projects.

He is known as a very active professor, directing theses and teaching constantly, and is regarded as a charismatic communicator and lecturer who is sought worldwide.

He obtained a PhD with the dissertation Community ecology and conservation of mammals in a Mayan tropical rain forest and abandoned agricultural fields[9].

Medellín's impact on conservation has been significant, being Councilor of the Commission of Natural Protected Areas (CONANP), his work has resulted in the recovery of endangered species such as the lesser long-nosed or tequila Bat (Leptonycteris yerbabuenae), the creation of new protected natural areas, the valuation of ecosystem services by bats, and the creation of conservation programs in cooperation with industry.

Medellín's work in CITES has led to high-level decisions in the context of sustainable use and conservation of sharks, protecting lizards, turtles, tropical fish, many mammals and birds, and promoting international cooperation.

For example, between the U.S., Mexico and china in order to join forces and stop the black market and illegal take of totoaba, a fish species whose exploitation accompanies the critically endangered vaquita (Phocoena sinus).

[14] Medellín is a Multidisciplinary Expert Panel (MEP) member of IPBES (UNEP), the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services,[15] His work studying and protecting mammals has spanned many continents, groups, and influenced both subjects through scientific findings applied to policy.

Medellín was the first non-U.S., non-European President of the Society for Conservation Biology (SCB) 2013–2015, and served on the board of directors of the organization for over 15 years.

Medellín's presence in the media is continuous, with dozens of appearances each year in national and international TV, radio, and press, from BBC, El País, Deutsche Welle, and the Wall Street Journal, to local influential publications.