Friday October 21, 2022
PhysOrg —
Gills are best known for helping most fish species breathe underwater. But less well known is the fact gills regulate the salt and pH balance of fishes’ blood, a vital role played by the kidneys in other animals. Collectively known as ion regulation, this lesser-known gill function has been traditionally thought to have evolved in tandem with breathing.
But surprising new research published in Nature is adding a new, early chapter to the evolutionary story of gills.
“Our work suggests that the early, simplified gills of our worm-like ancestors played an important role in ion regulation. And that role might have originated as early as the very inception of gills, well before they played any role in breathing,” says Dr. Michael Sackville, a zoologist who led the study while with the University of British Columbia (UBC).
“This really does flip the script on our understanding of how gills and gill function evolved.”