[3] He is a former member of the Scientific Advisory Council to the Prime Minister of India and the Head of the Western Ghats Ecology Expert Panel (WGEEP) of 2010, popularly known as the Gadgil Commission.

Initially intending to do research under Mead, Gadgil later changed subjects by hearing lectures of E. O. Wilson, "the brightest young star in the ecology-evolution end of biology at Harvard at that time," and subsequently did his doctoral research on mathematical ecology and fish behaviour, under the guidance of William Bossert,[9] one of Wilson's former students.

[14] He returned to India in 1971[15] and took up a job as a scientific officer at Agharkar Research Institute of the Maharashtra Association for Cultivation of Science, Pune where he stayed for two years.

[18] A decade later, in 1986, he was appointed as a member of the Scientific Advisory Council to Prime Minister of India, a post he held till 1990.

[18] In 1998, he was appointed the chairman of the Science and Technology Advisory Panel of Global Environment Facility, an agency under the United Nations.

[19] He is a member of the National Tiger Conservation Authority[18] and is the chairman of the committee proposing Environmental Education Curriculum at School level.

[21] Gadgil, an active sportsman during his college years, held the Maharashtra State Junior and Pune University high jump records in 1959 and 1961 respectively.

[22] He is married to Sulochana Gadgil, a noted meteorologist and a Harvard scholar, whom he met during his Fergusson College years.

[19] He has been credited by many with the introduction of quantitative investigations of ecology and animal behaviour in India and for including humans as a vital part of ecosystems.

[28] He developed a penchant for writing at an early age and his first publication was a series of ten articles on animal behaviour, published in Srishtidnyan, a Marathi language science magazine, when he was studying in the 10th standard.

[25] He has also published two books,[16] Nisarganiyojan Lokasahabhagane being one among them,[29] and over 40 articles in Marathi and handled a fortnightly column on natural history, in The Hindu, from 1999 till 2004.

[45] The Central University of Orissa honoured him with the degree of Doctor of Science (Honoris Causa) in 2013[26] and The Energy and Resources Institute (TERI) recognised the contributions of the Western Ghats Ecology Experts Panel (WGEEP) and its chairman with the Georgescu-Roegen Award in 2014.

[7] Elaeocarpus gadgilii, is a tree species described in 2021 from the Nelliampathy hills in Palakkad district of Kerala, India named in honour of him.