Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in this world. Diseases have always been present during the evolution, acting themselves as a natural selectors - the weaker organisms get sick and die. Not just humans, but all species have to establish a great protecting mechanism in order to survive. That is how our bodies are built, to be able to withstand and survive in the conditions we live in, and that is why our immune system has to be taken care of.
When cells in a body are not working properly and normally, they cause disruption in the body homeostasis.
Homeostatis is characterized as balance in the body but when there is any disturbance in the body, it breaks down the balance and cause imbalance. For example in the case of diabetes in which body fails to maintain the good amount of glucose in blood which results in imbalance the body which is why diabetic patients are asked to maintain and monitor their body sugar level to maintain homeostatis.
I think its the atmosphere ?????
By studying the fossil record we can tell how long life has existed on Earth, and how different plants and animals are related to each other. Often we can work out how and where they lived, and use this information to find out about ancient environments.
i believe the answer is "A fundamental role". hope this helps.
