Study of the proximate mechanisms of how work.

The term "work" in the definition is used as a for "function". Biological systems can range from the molecules making up living things to ecosystem. Contrast functional biology particularly with evolutionary biology.

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The functional biologist is vitally concerned with the operation and interaction of structural elements, from molecules up to organs and whole . His ever-repeated question is "How?" How does something operate, how does it function? The functional who studies an shares this method and approach with the who studies the function of a DNA molecule in the transfer of . The functional biologist attempts to isolate the particular component he studies, and in any given study he usually deals with a single individual, a single organ, a single cell, or a single part of a cell. He attempts to eliminate, or control, all , and he repeats his under constant or varying conditions until he believes he has clarified the function of the element he studies. The chief technique of the functional biologist is the experiment, and his approach is essentially the same as that of the and the . Indeed, by isolating the studied phenomenon sufficiently from the of the organism, he may achieve the ideal of a purely physical or chemical experiment. In spite of certain limitations of this method, one must agree with the functional biologist that such a simplified approach is an absolute necessity for achieving his particular objectives. The spectacular success of biochemical and research justifies this direct, although distinctly simplistic, approach.