Bones of the human body that grow, heal, provide structure were not always like this. A recent study that observed the fossilized remains of ancient fish has uncovered how the present-day bones evolved over 400 million years ago. Published in the journal Science Advances on Wednesday, the research shows how the first bones with living cells, like those found in modern humans, evolved about 400 million years ago and acted as skeletal batteries that supplied prehistoric fish with minerals needed to travel over greater distances.
The joint team of palaeontologists with Yara Haridy, a doctoral candidate at the Berlin Museum of Nature as its lead author, has for the first time analyzed bone structures in 400 million-year-old fossils of marine creatures called osteostracans, at unprecedentedly high resolution and in 3D. The team of tomography experts at the Helmholtz-Zentrum Berlin (HZB) examined the samples under the focused ion beam of a scanning electron microscope to calculate 3D images from the data, achieving resolutions in the nanometre range using technology that was initially developed to study battery corrosion.
These ancient species of fish had a hard, armour-encased front end and a flexible tail at the back. With no jaws, the fish had their bodies encased in bone tissue. With the help of hi-tech tools, scientists studied these fish that are critical to understanding the origins of the hard parts that shaped vertebrate evolution.
The research team also found that the bone tissue around the cell cavities was eaten away. However, it was not the sign of a disease or injury but a technique used by the bone cells that had dissolved some of the tissue to send the calcium, phosphorus, and other minerals inside into the ancient fish’s bloodstream. These cells turned bone tissues into a battery, releasing stored minerals needed for the bodily system such as nourishing the muscles needed to swim. This requirement for additional minerals helped fasten the evolution of cellular bones, a change that influenced the trajectory of vertebrates, mentions the research.