I was wondering, why did life form settle on using calcium for our bones, was there a data driven decision with forced life form to adapt to this? Does this make calcium organic? Are there animals out there who have different bone elements?
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There’s a bit of history to remember here, and a bit of biology. First is the biology, which needs Calcium for its ability to be a huge multitasker in nerve tissues. Once you start off with an organism already needing something, there’s a tendency in evolution to use it in other ways if possible. In the oceans, long before a vertebrate ever lived, you had boneless organisms using calcium for their nerves, but also in the form of calcium carbonate to form shells. It’s worth remembering all of that, because one of the answers to “why calcium” is “because it’s readily available and already present in organisms out of necessity.”
At some point in the deep evolutionary past, an organism that had internal collagen structures, but not bones based on calcium phosphate like us, started mineralizing that collagen and it was beneficial, conferring an evolutionary advantage. It was probably something small and primitive like lamprey or hagfish, and the bone was used in the jaw/teeth. There’s more to this story, such as the evolution of a new type of collagen, but it’s sort of beside the point for ELI5 purposes.
Once organisms started making bones, it was just a matter of time until the benefits of structural rigidity, armor, anchor points for tendons and ligaments, and the ability to support bursts of activity that invertebrates often can’t manage… drove evolution of some organisms in the direction of having skeletons.
tl;dr Organisms already need calcium, and bones may have first evolved as calcium storage devices, early teeth/jaws, and mineralized soft tissues.
There’s a bit of history to remember here, and a bit of biology. First is the biology, which needs Calcium for its ability to be a huge multitasker in nerve tissues. Once you start off with an organism already needing something, there’s a tendency in evolution to use it in other ways if possible. In the oceans, long before a vertebrate ever lived, you had boneless organisms using calcium for their nerves, but also in the form of calcium carbonate to form shells. It’s worth remembering all of that, because one of the answers to “why calcium” is “because it’s readily available and already present in organisms out of necessity.”
At some point in the deep evolutionary past, an organism that had internal collagen structures, but not bones based on calcium phosphate like us, started mineralizing that collagen and it was beneficial, conferring an evolutionary advantage. It was probably something small and primitive like lamprey or hagfish, and the bone was used in the jaw/teeth. There’s more to this story, such as the evolution of a new type of collagen, but it’s sort of beside the point for ELI5 purposes.
Once organisms started making bones, it was just a matter of time until the benefits of structural rigidity, armor, anchor points for tendons and ligaments, and the ability to support bursts of activity that invertebrates often can’t manage… drove evolution of some organisms in the direction of having skeletons.
tl;dr Organisms already need calcium, and bones may have first evolved as calcium storage devices, early teeth/jaws, and mineralized soft tissues.
There’s a bit of history to remember here, and a bit of biology. First is the biology, which needs Calcium for its ability to be a huge multitasker in nerve tissues. Once you start off with an organism already needing something, there’s a tendency in evolution to use it in other ways if possible. In the oceans, long before a vertebrate ever lived, you had boneless organisms using calcium for their nerves, but also in the form of calcium carbonate to form shells. It’s worth remembering all of that, because one of the answers to “why calcium” is “because it’s readily available and already present in organisms out of necessity.”
At some point in the deep evolutionary past, an organism that had internal collagen structures, but not bones based on calcium phosphate like us, started mineralizing that collagen and it was beneficial, conferring an evolutionary advantage. It was probably something small and primitive like lamprey or hagfish, and the bone was used in the jaw/teeth. There’s more to this story, such as the evolution of a new type of collagen, but it’s sort of beside the point for ELI5 purposes.
Once organisms started making bones, it was just a matter of time until the benefits of structural rigidity, armor, anchor points for tendons and ligaments, and the ability to support bursts of activity that invertebrates often can’t manage… drove evolution of some organisms in the direction of having skeletons.
tl;dr Organisms already need calcium, and bones may have first evolved as calcium storage devices, early teeth/jaws, and mineralized soft tissues.
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