Non-monophyletic grouping of organisms united by morphological or physiological characteristics
Cladogram (family tree) of a biological group. The green box (central) may represent an evolutionary grade (paraphyletic), a group united by conservative anatomical and physiological traits rather than phylogeny. The flanking red and blue boxes are clades (i.e., complete monophyletic subtrees).
A grade is a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit.[1]
^Huxley J. 1959. Clades and grades. In Cain A.J. (ed) Function and taxonomic importance. Systematics Association, London.
and 30 Related for: Evolutionary grade information
to fully understand evolutionarygrades, one must first get a better understanding of phylogenetics: the study of the evolutionary history and relationships...
Development and Evaluation (GRADE) approach Evolutionarygrade, a paraphyletic group of organisms Graded bedding, a description of the variation in grain...
wastebasket taxon may in some cases be retained as the designation of an evolutionarygrade, however. The term was coined in a 1985 essay by Steven Jay Gould...
studies have shown a supporting amount of evidence that Miacoidea is an evolutionarygrade of carnivoramorphs that, while viverravids are monophyletic basal...
scientists believed that modern ungulates were descended from an evolutionarygrade of mammals known as the condylarths. The earliest known member of...
protists were at that time thought to be "primitive forms", and thus an evolutionarygrade, united by their primitive unicellular nature. Understanding of the...
no longer considered a valid grouping, but rather a paraphyletic evolutionarygrade of basal mammals and mammaliaform cynodonts. Most of the animals in...
advanced radiation of a clade of smallish to largish rails, whose basal evolutionarygrade consists of larger species, many being flightless island endemics...
Madagascar, but are also found throughout Africa and in Asia. Being an evolutionarygrade rather than a clade, the prosimians are united by being primates with...
(clade) exclusive of other tetrapods. Instead, they consistute an evolutionarygrade (a paraphyletic group), ancestral to living tetrapods such as lissamphibians...
Gryposuchinae and Gryposuchus might be paraphyletic and rather an evolutionarygrade towards the gharial. The type species of Gryposuchus is G. jessei...
Rhamphorhynchoidea forms one of the two suborders of pterosaurs and represents an evolutionarygrade of primitive members of flying reptiles. This suborder is paraphyletic...
schemes have stabilized on a system where Rauisuchia is rendered an evolutionarygrade, or even a wastebin taxon. Crocodylomorphs most likely originated...
having given rise to Australidelphia, and thus could be considered an evolutionarygrade. Genetic studies indicate that they are the second most basal order...
Therefore, at its widest extent, the order Insectivora represented an evolutionarygrade rather than a clade. Taxonomy has been refined in recent years, and...
evidence indicate that Ameridelphia might best be understood as an evolutionarygrade. Since Didelphimorphia appears to be the basal marsupial group, it...
incorporates about 30 species) the genus is not monophyletic but an evolutionarygrade, as has long been suspected due to its lack of characteristic apomorphies...
reptiles and the birds. The class Reptilia has been known to be an evolutionarygrade rather than a clade for as long as evolution has been recognised....
It was believed they were the only surviving branch of the ancient evolutionarygrade Anapsida, which includes groups such as procolophonids and pareiasaurs...
ancestor Evidence of common descent – Common ancestor evolutionary evidence Evolutionarygrade – Non-monophyletic grouping of organisms united by morphological...
This traditional, informal usage of "Lobopodia" treats it as an evolutionarygrade, including only extinct Panarthropods near the base of crown Panarthropoda...
members of Archaeopterygidae, or an assemblage of dinosaurs that are an evolutionarygrade within Avialae or Paraves. Anchiornithids share many general features...
distinct clade—a group of closest relatives and nothing else—but an evolutionarygrade instead. As such, it is abandoned in modern treatments, being replaced...
paraphyletic groups to obscure inferred patterns of evolutionary history. The term "evolutionarygrade" is sometimes used for paraphyletic groups. Moreover...
argued that human fossils could be assigned a date, a race, and an evolutionarygrade. Coon divided humanity into five races and believed that each race...
animals (reptiles and birds) and the mammals. The group representing an evolutionarygrade rather than a clade, the term anamniote is now used as an informal...
representing the earliest landliving vertebrates. The group is thus an evolutionarygrade rather than a clade. While the group are recognized as having feet...
continues to the present day. It was long known that Mesosuchia was an evolutionarygrade, a hypothesis confirmed by the phylogenetic analysis of Benton and...
the adaptations of the crossbills represent a unique evolutionary path (see Evolutionarygrade), it seems more appropriate to split up the genus Carduelis...
extinct group of the first primitive, reptile-like birds. It is an evolutionarygrade of transitional fossils, the primitive birds halfway between non avian...
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