A new genetic study has revealed that the humans limbs may have evolved from the gill arches of sharks, skates and rays.
This may be down to a “Sonic the hedgehog” gene that is responsible in the formation and development of limbs, fins and gill arches.
Andrew Gillis, a biologist and researcher at the University of Cambridge who conducted the study with his team, now poses the question of whether the presence of this gene means that human limbs evolved from the gills of sharks.
“The shared role of Sonic hedgehog in patterning branchial rays and limbs may be due to a deep evolutionary relationship between the two or it may simply be that two unrelated appendages independently use the same gene for the same function.”
The findings back up a similar theory by German anatomist Karl Gegenbaur who saw the connection back in 1878 but was disclaimed due to lack of fossil evidence at the time.
The main focus was on the gill support structures made of cartilage known as branchial rays, according to UPI. The team studied the development of embryos of skate fish and found that if they switched off the Sonic the hedgehog gene then branchial rays formed on the wrong side of the gill arch which would be a similar result in human limbs.
“Branchial rays will figure prominently in the story of the evolutionary origin of vertebrate animal appendages, either by shedding light on the evolutionary antecedent of paired fins, limbs, or by teaching us about the genetic mechanisms that animals can use to invent new appendages.”
Gillis and his team are currently conducting the study at Marine Biological Laboratory in Woods Hole in Massachusetts and plan to delve more into the research later this year.
The findings were recently published in the journal Development.