Sample Statistics. 1  x refers to a sample mean. 2  s refers to the standard deviation of a sample. 3  s2 refers to the variance of a sample. 4  p refers to the proportion of sample elements that have a particular attribute. 5  q refers to the proportion of sample elements that do not have a particular attribute, so q = 1 - p.
Ecology/Environmental Response. The most basic interest of ecologists is how organisms interact with their environment. Inanimate objects do not normally interactâthey are simply acted upon by forces in the environment. Organisms, however, cannot be totally passive within a chain of events and still sustain life.
Organisms detect changes in their environment and respond to these changes in a variety of ways. These changes may occur at the cellular or organism level. The graphic above shows the response of a human to being struck on the knee with a hammer. A change in the environment is called a stimulus.