Since the work of Charles Darwin, it has been more or less accepted that people, horses, porpoises, and bats share a common ancestor — one that's arms and digits developed over many, many years to suit its needs. But only recent research has revealed that the human hand is actually extremely similar to the fin of a fish.
Although you wouldn't know it comparing your hand side-by-side with a trout (and might only guess it watching Michael Phelps swim), human fingers and fish fins "follow some of the same rules," The New York Times reports. In hands, we have a kind of tissue called "endochondral bone"; fish, however, have only small endochondral bones at the tip of their fin, the rest of the fin being made of rays of dermal bone. But by toggling with two genes related to limbs, scientists realized that the same cells in fish and in tetrapods either ask the body to develop dermal bones or endochondral bones.
The new discovery could help make sense of the intermediate fish with limb-like fins that [evolutionary biologist Dr. Neil H. Shubin] and his colleagues have unearthed. These animals still used the molecular addresses their ancestors used. But when their cells reached their addresses, some of them became endochondral bone instead of fin rays. It may have been a simple matter to shift from one kind of tissue to another. [The New York Times]
"Here we're finding that the digits and the fin rays have some sort of equivalence at the level of the cells that make them. Honestly, you could have knocked me over with a feather — it ran counter to everything that I was expecting after working on this problem for decades," Dr. Shubin told The New York Times.
The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
-
Jessica Francis Kane's 6 favorite books that prove less is moreFeature The author recommends works by Penelope Fitzgerald, Marie-Helene Bertino, and more
-
Trump's drug war is now a real shooting warTalking Points The Venezuela boat strike was 'not a mere law enforcement action'
-
Book reviews: 'Baldwin: A Love Story' and 'The Fort Bragg Cartel: Drug Trafficking and Murder in the Special Forces'Feature A loving James Baldwin biography and the drug crimes of two special ops veterans
-
SpaceX breaks Starship losing streak in 10th testspeed read The Starship rocket's test flight was largely successful, deploying eight dummy satellites during its hour in space
-
Rabbits with 'horns' sighted across Coloradospeed read These creatures are infected with the 'mostly harmless' Shope papilloma virus
-
Lithium shows promise in Alzheimer's studySpeed Read Potential new treatments could use small amounts of the common metal
-
Scientists discover cause of massive sea star die-offSpeed Read A bacteria related to cholera has been found responsible for the deaths of more than 5 billion sea stars
-
'Thriving' ecosystem found 30,000 feet underseaSpeed Read Researchers discovered communities of creatures living in frigid, pitch-black waters under high pressure
-
New York plans first nuclear plant in 36 yearsSpeed Read The plant, to be constructed somewhere in upstate New York, will produce enough energy to power a million homes
-
Dehorning rhinos sharply cuts poaching, study findsSpeed Read The painless procedure may be an effective way to reduce the widespread poaching of rhinoceroses
-
Breakthrough gene-editing treatment saves babyspeed read KJ Muldoon was healed from a rare genetic condition
