physical and social ossification

Manuel Delanda explains in Matter Matters:

Bones are interesting for a variety of reasons. Like fiberglass and other composites, they are a hybrid of glue and grit, with collagen playing the role that epoxy resin plays in human-made composites, and tiny mineral crystals playing the role of the thin glass fibers. To the extent that humans have been using composites since they first used straw brick, the principle of combining glue and grit to get novel emergent properties was already known to us.