On this World Anatomy Day, Oct. 15, experts in the Center for Functional Anatomy and Evolution at Johns Hopkins Medicine are working to find answers to evolutionary mysteries. Using modern tools to take a closer look at the fossil record, their findings could help pave the way for future biomedical research.
Journalists planning related stories should contact Alexandria Carolan () or Vanessa Wasta () to connect with the following experts.
The Unexpected Origin of the Toothache
Matteo Fabbri, Ph.D., assistant professor of functional anatomy and evolution
Why are our teeth sensitive to hot or cold temperatures? Matteo Fabbri says this ability evolved from an ancient fish.
In recent research published in Nature, Fabbri and his research collaborators outlined how fish known as Anatolepis heintzi, which lived during the Ordovician period about 465 million years ago, first developed sensitive structures on their skin made of dentin to sense their environment. Dentin is the mineralized tissue that surrounds and protects nerves under the white enamel of mammalian teeth.
"When you have a toothache, it's an evolutionary-driven feeling," Fabbri says. The research was conducted in part with funding from the National Science Foundation and the U.S. Department of Energy.
By studying the embryology (development) of organisms, Fabbri says he aims to determine how certain systems in the bodies of vertebrates evolved, answering evolutionary questions.
Modern Bird Brains Hold Clues to Human Behavior
Amy Balanoff, M.S., Ph.D., assistant professor of functional anatomy and evolution
Birds are living dinosaurs, Amy Balanoff says.
To understand how the brains of birds evolved, Balanoff and her team of researchers explore their dinosaur ancestors, specifically the fossils of non-avian dinosaurs. Using modern tools, including digital endocasts and PET scans, Balanoff says her team of researchers wants to learn what the brains of non-avian dinosaurs can tell us about modern bird behaviors.
"There are a lot of really interesting things we can learn from the bird brain by exploring their deeper evolutionary history," Balanoff says of her National Science Foundation-funded research.
These connections in brain evolution can tell scientists more about mammals, too, as both groups are amniotes (originating from an egg). Specifically, Balanoff says birds and mammals are the only two amniote groups that have a "big brain" and walk on two legs. Also, the human ability to learn language is similar to how birds learn a song, she says.
The Way Turtles Breathe May Inform Molecular Roots of Chest Conditions in Mammals
Turtles are an evolutionary and biological mystery, Gabriel Bever says.
The structure of their ribs is different from that of mammals, he says, causing the animals to breathe in a unique way. Their ribs are positioned high in their body plan and become integrated into the shell itself. When turtles breathe, Bever says they have modified belly muscles that ventilate their lungs by squeezing them against their upper shell. Meanwhile, when mammals breathe, muscles help expand the rib cage.
By studying fossils of turtles from 260 million years ago with funding from the National Science Foundation, Bever hopes to answer questions about how turtles developed such an interesting body plan.
The formation of the turtle's thoracic wall can hint at conditions that affect the thoracic wall in mammals, Bever says, including a condition in which the bones of mammals become hyper-ossified, or develop excessive bone. Bever says he has determined some of the mechanisms and genes underlying the development of turtle shells, which match those that are shown to cause hyper-ossification of certain bones in mice.
