I think it might be <em>natural disasters.</em>
If a burning splint is placed in a container and burns more brightly in the presence of some gas already in the cylinder, that gas would probably be Oxygen.
Oxygen is the main component of air that we need to breathe. It is the most commonly available oxidizer. Besides combustion, it plays many roles in our life such as; the food we eat requires oxygen which helps in digestion and absorption of nutrients by the cells.
<span>The difference that you are searching for is the addition of Appendages. They appeared in Cambrian animals and were used to increase their physical capabilities like when sensing and processing the information found in the environment. Common appenadges found in animals are things like antennae found in insects that are used to help them communicate or notice things or similar things.</span>
A rigid cell wall is found in plants so they can hold themselves up.
