Homology (biology)

In the context of biology, homology is the existence of shared ancestry between a pair of structures, or genes, in different species. A common example of homologous structures in evolutionary biology are the wings of bats and the arms of primates. Evolutionary theory explains the existence of homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.

In the context of sexual differentiation—the process of development of the differences between males and females from an undifferentiated fertilized egg—the male and female organs are homologous if they develop from the same embryonic tissue. A typical example is the ovaries of female humans and the testicles of male humans.

Etymology

The word homology, coined in about 1656, derives from the Greek ὁμόλογος homologos from ὁμός homos "same" and λόγος logos "relation". In biology, two things are homologous if they bear the same relationship to one another, such as a certain bone in various forms of the "hand". The alternative term homogeny was also used in the early 1900s.

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.

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