The Bone To Flesh Ratio

I have a new concept in the development of life on earth. I have named it "The Bone To Flesh Ratio". My new concept predicts the average physical size of species that depend on bone for structure; mammals, humans, reptiles and, bony fishes.

Millions of years ago, the average size of these creatures was much greater than today due to the existence of dinosaurs and giant sea creatures. The age of mammals did not begin until dinosaurs were gone. My hypothesis predicts that in the distant future, bone-based creatures will get smaller still.

The reason is simple. When a creature dies, it's body decays and the component atoms return to the biosphere to become part of plants and other creatures.

But in creatures that depend on bone for structure, there is a catch. The bone is composed of different atoms than the flesh, such as calcium and phosphorus. When the creature dies, the flesh decomposes and it's atoms return to the biosphere in a short time. But the creature's bones do not. Bones, or even the complete skeleton can remain intact for many thousands of years.

So, bone matter does not return to circulation in the biosphere at anything like the same rate as flesh. Furthermore, the fact that bone remains intact for so long means that it may become so deeply buried that it never returns to circulation in the biosphere. This means that as time goes on, more and more bone matter is being removed from circulation in the biosphere relative to flesh matter. In other words, the bone to flesh ratio gets ever lower.

This is why the physical size of the average species dependent on bone today is much smaller than it was a hundred million years ago, according to my hypothesis. Dinosaurs are what bone-based life would be like if there was unlimited bone matter available. Size would be an evolutionary survival advantage in being bigger than one's competitors.

The dinosaurs existed for maybe a couple of hundred million years age before going extinct around sixty-five million years ago. During this long era of the dinosaurs, a vast amount of bone matter was removed from circulation in the biosphere. Larger bones have a lower surface area in relation to volume and so would decay even slower than smaller bones.

I would like to give an excellent example of the bone to flesh ratio by considering life in the sea. My observation is that life in the sea is also limited in size but it is due to another factor. Unlike on land, bone material in the sea is plentiful but the size of fish is limited by the availability of oxygen. Fish process oxygen through their gills but water can hold only a limited amount of dissolved oxygen. There is no oxygen limit to size on land and no bone limit to size in the sea because bone material dissolves and recirculates to the biosphere.

This, then is my observation in the limits set to how big creatures can grow; the availability of oxygen sets the limit in the water and the availability of bone matter sets the limit on land. Smaller fish have a greater surface to volume ratio.

Now let's consider whales, which are by far the largest creatures on earth. The Bone to Flesh ratio explains how the whale attains it's size. The whale gets the best of both worlds by living in the sea for the abundant bone material but coming to the surface to breathe air like creatures on land. the whale is not a fish but a mammal with lungs instead of gills.