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Something To Cluck About

Evolution is all around us.


Walking is evolution. Language is evolution. Frankly, the world around us is all evolution. “Evolution … is a force that has shaped every organism living today.” (National Geographic.)


Reading an awesome book about chickens, Under the Henfluence: Inside the World of Backyard Chickens and the People Who Love Them by Tove Danovich, we were reminded of a fun fact about the nation’s most popular poultry.


It’s this:


Chickens are the closest living relative of T. rex.


This scientific tidbit goes back to research published sixteen years ago in Science. “Paleontologist used material discovered in a chance find in 2003 to pin down the link,” wrote Smithsonian Magazine in 2008.

For a great animated visual of the evolution, check out this video by World in Numbers 3D beginning with Proceratosaurus (166 million years ago) through Tyrannosaurus Rex (68 million years ago) to Gallus Gallus (5 million years ago to present day) and Gallus domesticus.


The “dinosaur-ness” of birds had been suspected for many years based on anatomical similarities, the article noted, but the research revealed the first molecular evidence.


How did they get molecular proof from an animal that died out 65 million years ago?


It happened when they needed to break a giant T. rex femur in order to fit it inside a helicopter. Collagen molecules from inside the bone contained a structural protein that they could compare with 21 living animals. The closest match? The aforementioned chickens and ostriches.


Well, what’s new in the work to connect chickens and T. rex?


Thanks for asking.


A couple decades of careful phylogenetic work has demonstrated that birds “are nested within the group of small, mostly predatory, and running dinosaurs that include dromaeosaurs and troodontids,” reported Science in 2001.


Phylogenetic work, by the way, is the study of evolutionary relationships among biological entities.


Scientists, being scientists, weren’t content to leave it there. They are using that “phylogenetic tapestry,” wrote Science, “to trace the evolution of traits such as sensory biology and behavior.”


It turns out the inner ear of dinosaurs, as well as that of other archosaurs (the group that includes crocodilians, dinosaurs, and birds) provides clues to location, hearing, and the evolution of vocalization.


Speaking of which—and another topic well covered in Under The Henfluence—chickens make up to 30 different tones and sounds. Care to learn their language? Well, again, head to YouTube for many guides. (Here’s one.) Listen closely, maybe you’re hearing an evolutionary connection to a creature that roamed North American and Asia 90 million to 66 million years ago during the Late Cretaceous.


Quick final note: the origins of T. Rex are still up for debate. Did it come from Asia and cross the land bridge to North America? And when? A recent analysis of a New Mexico fossil suggests new theories are needed. 


See? Science—and evolution—marches on.







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