A widely debated topic in biology and fisheries sciences is the role of oxygen in the growth of fish and other water-breathing animals. According to new research, developmental changes in individual ...

Fish embryo study indicates that the last common ancestor of vertebrates was a complex animal complete with gills -- overturning prior scientific understanding and complementing recent fossil finds.

A new study has revealed that gills originated much deeper in evolutionary history than previously believed. The findings support the idea that gills evolved before the last common ancestor of all ...