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Tokogeny or tocogeny is the biological relationship between parent and offspring, or more generally between ancestors and descendants. In contradistinction to phylogeny it applies to individual organisms as opposed to species.

In the tokogentic system shared characteristics are called traits. [1]

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Cladistics is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics (synapomorphies) that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms worms or fishes were used within a strict cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a 'grade', which are fruitless to precisely delineate, especially when including extinct species. Radiation results in the generation of new subclades by bifurcation, but in practice sexual hybridization may blur very closely related groupings.

In biology, phylogenetics is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms.

<span class="mw-page-title-main">Paraphyly</span> Type of taxonomic group

In taxonomy, a grouping is paraphyletic if it consists of the grouping's last common ancestor and most of its descendants, but excludes a few monophyletic subgroups. The grouping is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic grouping includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic.

<span class="mw-page-title-main">Polyphyly</span> Property of a group not united by common ancestry

A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly. It is contrasted with monophyly and paraphyly.

<span class="mw-page-title-main">Autapomorphy</span> Distinctive feature, known as a derived trait, that is unique to a given taxon

In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to the focal taxon. It can therefore be considered an apomorphy in relation to a single taxon. The word autapomorphy, first introduced in 1950 by German entomologist Willi Hennig, is derived from the Greek words αὐτός, autos "self"; ἀπό, apo "away from"; and μορφή, morphḗ = "shape".

<span class="mw-page-title-main">Norman I. Platnick</span> American arachnologist (1951–2020)

Norman Ira Platnick was an American biological systematist and arachnologist. At the time of his death, he was a professor emeritus of the Richard Gilder Graduate School and Peter J. Solomon Family Curator Emeritus of the invertebrate zoology department of the American Museum of Natural History. A 1973 Ph.D. recipient at Harvard University, Platnick described over 1,800 species of spiders from around the world, making him the second most prolific spider taxonomist in history, behind only Eugène Simon. Until 2014 he was also the maintainer of the World Spider Catalog, a website formerly hosted by the AMNH which tracks the arachnology literature, and attempts to maintain a comprehensive list, sorted taxonomically, of every species of spider which has been formally described. In 2007 he received the International Society of Arachnology's Bonnet award, named for Pierre Bonnet, in recognition of his work on the catalog.

<span class="mw-page-title-main">Austrochilidae</span> Family of spiders

Austrochilidae is a small spider family with nine species in two genera. Austrochilus and Thaida are endemic to the Andean forest of central and southern Chile and adjacent Argentina.

<span class="mw-page-title-main">Prodidomidae</span> Subfamily of spiders

Prodidomidae is a family of spider, sometimes called long-spinneret ground spiders. It was formerly regarded as a subfamily of Gnaphosidae, but was raised to a family in 2022.

<span class="mw-page-title-main">Anapidae</span> Family of spiders

Anapidae is a family of rather small spiders with 232 described species in 58 genera. It includes the former family Micropholcommatidae as the subfamily Micropholcommatinae, and the former family Holarchaeidae. Most species are less than 2 millimetres (0.079 in) long.

<span class="mw-page-title-main">Archaeidae</span> Family of spiders

Archaeidae, also known as assassin spiders and pelican spiders, is a spider family with about ninety described species in five genera. It contains small spiders, ranging from 2 to 8 millimetres long, that prey exclusively on other spiders. They are unusual in that they have "necks", ranging from long and slender to short and fat. The name "pelican spider" refers to these elongated jaws and necks used to catch their prey. Living species of Archaeidae occur in South Africa, Madagascar and Australia, with the sister family Mecysmaucheniidae occurring in southern South America and New Zealand.

<span class="mw-page-title-main">Palpimanoidea</span> Superfamily of spiders

The Palpimanoidea or palpimanoids, also known as assassin spiders, are a group of araneomorph spiders, originally treated as a superfamily. As with many such groups, its circumscription has varied. As of September 2018, the following five families were included:

<span class="mw-page-title-main">Araneoidea</span> Superfamily of spiders

Araneoidea is a taxon of araneomorph spiders, termed "araneoids", treated as a superfamily. As with many such groups, its circumscription has varied; in particular some families that had at one time moved to the Palpimanoidea have more recently been restored to Araneoidea. A 2014 treatment includes 18 families, with the araneoids making up about 26% of the total number of known spider species; a 2016 treatment includes essentially the same taxa, but now divided into 17 families.

<span class="mw-page-title-main">Haplogynae</span>

The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata.

In biology, a species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour, or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.

<span class="mw-page-title-main">Caponiidae</span> Family of spiders

Caponiidae is a family of ecribellate haplogyne spiders that are unusual in a number of ways. They differ from other spiders in lacking book lungs and having the posterior median spinnerets anteriorly displaced to form a transverse row with the anterior lateral spinnerets. Most species have only two eyes, which is also unusual among spiders. A few species of Caponiidae variously have four, six or eight eyes. In some species the number of eyes will increase when the spiderling changes its skin as it grows towards adulthood.

<span class="mw-page-title-main">Quentin D. Wheeler</span> American entomologist (born 1954)

Quentin Duane Wheeler is an American entomologist, taxonomist, author and newspaper columnist, and is the founding director of the International Institute for Species Exploration. He was the fourth President of the State University of New York College of Environmental Science and Forestry, in Syracuse, New York until his retirement. Other positions have included: professor of entomology at Cornell University and Arizona State University; Keeper and Head of Entomology at the Natural History Museum in London; and Director of the Division of Environmental Biology at the National Science Foundation.

Transformed cladistics, also known as pattern cladistics is an epistemological approach to the cladistic method of phylogenetic inference and classification that makes no a priori assumptions about common ancestry. It was advocated by Norman Platnick, Colin Patterson, Ronald Brady and others in the 1980s, but has few modern proponents. The book, Foundations of Systematics and Biogeography by David Williams and Malte Ebach provides a thoughtful history of the origins of this point of view.

Synotaxus is a genus of araneomorph spiders in the family Synotaxidae that was first described by Eugène Louis Simon in 1895. Originally placed with the tangle web spiders, it was moved to the family Synotaxidae in 2017.

Myrmecicultor is a monotypic genus of North American spiders in the family Myrmecicultoridae. It contains the single species, Myrmecicultor chihuahuensis, and was first described by M. J. Ramírez, C. J. Grismado and D. Ubick in 2019. It is native to the Chihuahuan Desert, from the Big Bend region of Texas to Coahuila and Aguascalientes in Mexico. Collected specimens were found in pitfall traps where three species of harvester ants are most active: Pogonomyrmex rugosus, Novomessor albisetosis, and Novomessor cockerelli.

Brent D. Mishler is an American botanist who is director of the University and Jepson Herbaria at the University of California, Berkeley as well as Distinguished Professor in the Department of Integrative Biology, where he teaches phylogenetics, plant diversity, and island biology.


  1. Quentin R. Wheeler and Norman I. Platnick (21 August 2012). "5: The Phylogenetic Concept ( sensu Wheeler and Platnick)". Species Concepts and Phylogenetic Theory: A Debate. Editors: Quentin Wheeler, Rudolf Meier. Columbia University Press, 2000. ISBN   978-0231101424.