Have you ever imagined what life would be without bones? It is lunchtime and you are trying to eat a sandwich, but you are trying to do this without teeth, or a jaw, or hands. Eating a sandwich for lunch would be impossible without a skeleton, and all of our daily activities would become impossible as well. The skeletal system is too often taken for granted. Its importance on life on Earth today is not emphasized nearly as much as it should be. The evolution of bones is what allowed for the vast differentiation of multicellular life on Earth. Dating back somewhere around 635-545 million years ago life consisted of only soft-bodied creatures floating around in the ocean. These creatures resemble something like our jellyfish of today. So how did we get from jellyfish to modern-day humans with skeletons?
Initiation of Bone Formation
In Darja Wagner and Per Aspenberg’s article entitled, Where Did Bone Come From, it states that at roughly 1.5 billion years ago all life resided in the ocean, and the tectonic plates were actively shifting at this time. Bone did not just appear out of thin air one day it was several initiating factors that brought about the transition from soft bodied to hard-bodied life. It is the shifting of these tectonic plates that jumpstarted the transition to bone (6). The movement of tectonic plates released various minerals into the oceans through hydrothermal vents. One of these various minerals being released was calcium carbonate (CaCO3), and this mineral played a key role in the formation of bone (6). Calcium carbonate did two things for living organisms; it aided the break down of minerals that were being absorbed from the ocean water, and also led to the ability to develop hard structures (6). Additionally, it is also important to note that calcium carbonate aided in the formation of an exoskeleton something along the lines of a shell. This development of hard body parts was the driving force for the Cambrian explosion allowing for the ability for such great complexity of life on Earth (6).
The Struggle of Tracking Bone Through Time
As calcium carbonate starts to accumulate in the bodies of organisms, they are able to form hard body parts. Scientists have not had the easiest time tracing back and deciphering the exact evolution of bone. The primary complication is that bone formation lies in the embryonic development of animals and this cannot be observed from fossils (2). Regardless of this constant struggle scientists have gathered evidence that explains the steps that the evolution of bone took. During the early Ordovician period bones origin come from the notochord of a fish that lacks a jaw and sensory organs, then its followed by the the internalized cartilaginous skeleton, and finally came the internal mineralized skeleton (6). This brief overview helps to give an idea of the struggle that scientists have to tackle it is literally millions and millions of year’s worth of bone to assimilate into an accurate order....