Image Credit: Jeff Levinton

Biologists have been plagued with the question, “Fish evolved in the oceans, but fresh waters have more species. Why?” It has been documented that our oceans today contain only 15-20% of the fish species despite the fact that it is believed that all fish evolved from the oceans making their way to the freshwater bodies. Well, John J. Wiens of Brook University is the Associate Professor in the Department of Ecology and Evolution address this question. Dr. Wiens published his findings in the February edition of Proceedings of the Royal Society. For a briefer understanding of this question review the interview with Dr. Wiens conducted by Benjamin Dual on behalf of EarthSky.