In phylogenetics In biology, phylogenetics is the study of evolutionary relatedness among various groups of organisms , which is discovered through molecular sequencing data and morphological data matrices. The term phylogenetics is of Greek origin from the terms phyle/phylon (φυλή/φῦλον), meaning "tribe, race," and genetikos (γενετικός, a trait is derived if it is present in an organism, but was absent in the last common ancestor of the group being considered. This may also refer to structures that are not present in an organism, but were present in its ancestors, i.e. traits that have undergone secondary loss. Here the lack of a structure is a derived trait.
For the sake of precision, the term "derived" is preferred to "advanced," a term which may inaccurately imply superiority. Simplicity is often secondarily derived.[1] For example, the absence of mitochondria In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 10 micrometers (μm) in diameter. Mitochondria are sometimes described as "cellular power plants" because they generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of in the anaerobic protist Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista but this group is contested in modern taxonomy. Instead, it is "better regarded as a loose grouping of 30 or 40 disparate phyla with diverse combinations of trophic modes, mechanisms of motility, cell coverings and life Entamoeba histolytica Entamoeba histolytica is an anaerobic parasitic protozoan, part of the genus Entamoeba. Predominantly infecting humans and other primates, E. histolytica is estimated to infect about 50 million people worldwide. Many older textbooks state that 10% of the world population is infected, but these figures predate the recognition that at least 90% of is a result of their secondary loss, and when considered in the context of eukaryotes as a whole, is a derived trait.[2] Likewise, the primitive character state for birds (i.e. the state possessed by their last common ancestor) is flight, which was secondarily lost by penguins and dodos.
Whether or not a trait is considered derived depends on the group in question. For example, among the (crown group) tetrapods, having five fingers is the primitive trait - as their last common ancestor bore a five-digit hand.[citation needed] However, amongst the vertebrates, five fingers is a derived trait, as the last common ancestor to the vertebrates did not even bear fingers.
In programming languages A programming language is an artificial language designed to express computations that can be performed by a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine, to express algorithms precisely, or as a mode of human communication, the word derived is used in connection with object-oriented programming Object-oriented programming is a programming paradigm that uses "objects" – data structures consisting of datafields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction, encapsulation, modularity, polymorphism, and as an alternative way of describing class inheritance In object-oriented programming , inheritance is a way to form new classes (instances of which are called objects) using classes that have already been defined. Inheritance is employed to help reuse existing code with little or no modification. The new classes, known as Sub-classes (or derived classes), inherit attributes and behavior of the pre-.
References
- ^ Clark, C.G. (1999). "The Effect of Secondary Loss on Our Views of Eukaryotic Evolution". The Biological Bulletin (Marine Biological Laboratory) 196 (3): 385–388. doi A digital object identifier is a character string used to uniquely identify an electronic document or other object. Metadata about the object is stored in association with the DOI name and this metadata may include a location, such as a URL, where the object can be found. The DOI for a document is permanent, whereas its location and other metadata:10.2307/1542976. http://www.biolbull.org/cgi/reprint/196/3/385.pdf.
- ^ Clark CG, Roger AJ (July 1995). "Direct evidence for secondary loss of mitochondria in Entamoeba histolytica". Proc. Natl. Acad. Sci. U.S.A. 92 (14): 6518–21. PMID A PMID is a unique number assigned to each PubMed citation of life sciences and biomedical scientific journal articles. The related Pubmed Central archive may additionally assign a separate number, a PMCID (PubMed Central Identifier), normally written with a PMC prefix 7604025. PMC PubMed Central is a free digital database of full-text scientific literature in biomedical and life sciences. It grew from the online Entrez PubMed biomedical literature search system. PubMed Central was developed by the U.S. National Library of Medicine as an online archive of biomedical journal articles 41549. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=7604025.
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A number of wall paintings discovered within various Egyptian temples and tombs contain illustrations of persons playing board games The illustrations have been typically dated at around 2500 B C One such game with similarities to the modern physical format of backgammon is the game of Sen t or Senat Actual game boards and assorted gaming paraphernalia were discovered in a number of Egyptian tombs dating from the First Dynasty to the Twelfth Dynasty 3000 1788 B C Various commentators 4 2 have suggested that the concept of board games was originally derived from other games of chance which in turn had their origins in the divinatory use of the arrow head Other historians perceive their origin to lie in the realm of the occult 3 In general commentators attribute the origins of backgammon to the ancient board games played by the Egyptians Sumerians Romans and Persians Recreational board games employing skill and or chance are an almost universal feature throughout the panopl…
