Function (biology)

A biological function is the reason some object or process occurred in a system that evolved through a process of selection or natural selection. Thus, function refers forward from the object or process, along some chain of causation, to the goal or success. Compare this to the mechanism of the object or process, which looks backward along some chain of causation, explaining how the feature occurred.

A functional characteristic is known as an adaptation, and the research strategy for investigating whether a character is adaptive is known as adaptationism. Although an assumption that a character is functional may be fruitful as a research method, some characteristics of organisms are non-functional, and may simply be emergent phenomena arising as a side effect of functional systems (see Spandrel (biology)). They may also have a reduced function or lost function entirely over time due to changing conditions, in which case they are said to be vestigial.

The correlation of form (also referred to as structure) and function is one of the central themes in biology. However, knowing the structure of something does not necessarily reveal its function. To illustrate the point, an enzymologist discovering an unknown enzyme would be highly unlikely to identify its function with only structural information. It is also possible for different structures to carry out the same function. Teeth and the gizzard of a bird highlight this point: both grind up food, serving the same function in terms of digestion.

Function

Function may refer to:

Math, computing and engineering

Music

Other uses

See also

Ξ function

In mathematics, the Ξ function (named for the Greek letter Ξ or Xi) may refer to:

Minkowski's question mark function

In mathematics, the Minkowski question mark function (or the slippery devil's staircase), denoted by ?(x), is a function possessing various unusual fractal properties, defined by Hermann Minkowski (1904, pages 171–172). It maps quadratic irrationals to rational numbers on the unit interval, via an expression relating the continued fraction expansions of the quadratics to the binary expansions of the rationals, given by Arnaud Denjoy in 1938. In addition, it maps rational numbers to dyadic rationals, as can be seen by a recursive definition closely related to the Stern–Brocot tree.

Definition

If is the continued fraction representation of an irrational number x, then

whereas:

If is a continued fraction representation of a rational number x, then

Intuitive explanation

To get some intuition for the definition above, consider the different ways of interpreting an infinite string of bits beginning with 0 as a real number in [0,1]. One obvious way to interpret such a string is to place a binary point after the first 0 and read the string as a binary expansion: thus, for instance, the string 001001001001001001001001... represents the binary number 0.010010010010..., or 2/7. Another interpretation views a string as the continued fraction [0; a₁, a₂, … ], where the integers a_i are the run lengths in a run-length encoding of the string. The same example string 001001001001001001001001... then corresponds to [0; 2, 1, 2, 1, 2, 1, …] = √3 − 1/2. If the string ends in an infinitely long run of the same bit, we ignore it and terminate the representation; this is suggested by the formal "identity":

Biology

Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy. Modern biology is a vast and eclectic field, composed of many branches and subdisciplines. However, despite the broad scope of biology, there are certain general and unifying concepts within it that govern all study and research, consolidating it into single, coherent fields. In general, biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the synthesis and creation of new species. It is also understood today that all organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable and vital condition.

Subdisciplines of biology are defined by the scale at which organisms are studied, the kinds of organisms studied, and the methods used to study them: biochemistry examines the rudimentary chemistry of life; molecular biology studies the complex interactions among biological molecules; botany studies the biology of plants; cellular biology examines the basic building-block of all life, the cell; physiology examines the physical and chemical functions of tissues, organs, and organ systems of an organism; evolutionary biology examines the processes that produced the diversity of life; and ecology examines how organisms interact in their environment.

Biology (journal)

Biology is a quarterly, peer-reviewed, open access, scientific journal covering research on all aspects of biology. It was established in 2012 and is published by MDPI. The editor-in-chief is Chris O'Callaghan (University of Oxford). The journal publishes reviews, research papers, and communications.

Subject Areas

This journal covers all topics related to biology. More detail about the journal and its scope is available in the first editorial. Research fields of interest include, but are not limited to:

Biology: The Unity and Diversity of Life

Biology: The Unity and Diversity of Life is a college-level introductory biology textbook that covers basic biochemistry, anatomy, taxonomy, evolution, biotechnology and ecology. The book is designed to create in students a broad foundation of knowledge in biology and is frequently used in AP Biology classes in American high schools. Each book includes an interactive CD-ROM with links to additional instructional material. Like many textbooks new versions are printed every few years and reflect new gains in scientific knowledge. The book is published by Brooks/Cole and is currently in its twelfth edition. It was primarily compiled by Cecie Starr and Ralph Taggart with pictures and illustrations by Lisa Starr.

The book was translated into few languages, among others into Hebrew, published by the Open University of Israel.

External links