Most philosophers agreed on the fact that there is nothing in world that is constant; everything is in a state of dynamism. Although some few others disagree with this stand, however, what we witness daily testifies to the acuity of the former stand; life keeps changing.
Change is a natural phenomenon that comes to play anytime. Some changes could be however mediated, while some others could be beyond the control of man. Nevertheless, nature has a way of keeping life balanced; there are many natural checks to this effect. Yet, the efforts make by nature to stabilize things is also brought about due to the constant change of things. Hence, when there is change, especially to the adverse side in nature, the nature changes so as to keep life going on smoothly.
A practical example of this is the body system of human. When there is change in the concentration of body fluid and the concentration of ions in the blood becomes high, the body quickly responds to this through some physiological process and as a result of this, man starts to feel thirsty. This is a sharp response of the body to such change.
However, there could be changes sometimes which would have a serious adverse effect on the nature. This change won’t apparently be for stabilization of nature, but a calamity. Such happens suddenly and without prior notice. Because of these sudden changes, man is usually negatively affect man; it could lead to loss of lives, properties, disruption in the earth structure and many others. Examples of these are earthquake and tsunami; both usually strike without a full and evasive warning.
Just the way unpredictable nature is, so also is man. There is nothing about man that is fully predictable; not his behaviour nor his health. In case of health, although some sicknesses are symptomatic, i.e. give symptoms, however, the time of these symptoms and the portentous disease would strike is virtually unpredictable. Therefore, diseases and many other incidence that happen to man come suddenly, but human beings, however, have created tools, such as health coverage and life insurance, to protect themselves. Hope we could do something similar to save the other species too.