Backbones are the foundation for common animals. A backbone is also known as a spine, or a vertebrae. However, animals didn't always have a backbone. Our earliest ancestor has been found as organisms resembling sponges recently discovered in African rocks. That means all animal life could draw a line straight back to this organism. This organism did not contain a backbone. But if we had to have evolved from this organism then how do we have a vertebrae?
Evolution! We got the backbone from an animal with a slightly stronger body due to mutations in the genomes of these organisms. Since it had a stronger body, it was able to detach itself from the shelter of the rocks, and be able to survive! Eventually, due to the increased amount of calcium from the erosion of rocks, and the intake of the free calcium into the organisms' system, these "strong bodies" developed into bones. The back of the creature, which would support the entire body, had to become stronger than the rest of the bones. It developed disks of bone connected by tendons and muscles for structural flexibility. These strong support systems allowed animals to grow to bigger sizes. Imagine! Something as big as a dinosaur came from an object as small as a sponge!
Evolution! We got the backbone from an animal with a slightly stronger body due to mutations in the genomes of these organisms. Since it had a stronger body, it was able to detach itself from the shelter of the rocks, and be able to survive! Eventually, due to the increased amount of calcium from the erosion of rocks, and the intake of the free calcium into the organisms' system, these "strong bodies" developed into bones. The back of the creature, which would support the entire body, had to become stronger than the rest of the bones. It developed disks of bone connected by tendons and muscles for structural flexibility. These strong support systems allowed animals to grow to bigger sizes. Imagine! Something as big as a dinosaur came from an object as small as a sponge!