Question

I have a quick question. why do some animals have a backbone and others don't

Answer 1

Animals are classified into two main groups: vertebrates and invertebrates. The main difference between vertebrates and invertebrates is that invertebrates, like insects and flatworms, do not have a backbone or a spinal column. Some examples of vertebrates include humans, birds, and snakes.

Answer 2

Step-by-step explanation:

Animals with a backbone belong to a group called vertebrates, while animals without a backbone belong to a group called invertebrates. The backbone, also known as the vertebral column or spine, is a flexible rod-like structure that runs along the dorsal (back) side of the body and provides support and protection for the nervous system.

The evolution of the backbone and the development of vertebrates are thought to have arisen as a result of various environmental pressures and adaptations over time. It is believed that early vertebrates developed a more complex nervous system and musculature, which enabled them to be more mobile and better equipped to survive in their environment. As a result, they evolved a backbone to protect this important structure and provide support for their bodies.

Invertebrates, on the other hand, have evolved a wide variety of different structural adaptations to meet the challenges of their environments, such as exoskeletons, shells, or hydrostatic skeletons. These adaptations provide support and protection for their bodies without the need for a backbone.