Ads
related to: clade examples in biology for kids worksheetsmartholidayshopping.com has been visited by 1M+ users in the past month
Search results
Results From The WOW.Com Content Network
The crown age of a clade refers to the age of the most recent common ancestor of all of the species in the clade. The stem age of a clade refers to the time that the ancestral lineage of the clade diverged from its sister clade. A clade's stem age is either the same as or older than its crown age. [15] Ages of clades cannot be directly observed.
It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants.
Willi Hennig 1972 Peter Chalmers Mitchell in 1920 Robert John Tillyard. The original methods used in cladistic analysis and the school of taxonomy derived from the work of the German entomologist Willi Hennig, who referred to it as phylogenetic systematics (also the title of his 1966 book); but the terms "cladistics" and "clade" were popularized by other researchers.
Ovalentaria is a clade of ray-finned fishes within the Percomorpha, referred to as a subseries.It is made up of a group of fish families which are referred to in Fishes of the World's fifth edition as incertae sedis, as well as the orders Mugiliformes, Cichliformes, and Blenniiformes.
The term sister group is used in phylogenetic analysis, however, only groups identified in the analysis are labeled as "sister groups".. An example is birds, whose commonly cited living sister group is the crocodiles, but that is true only when discussing extant organisms; [3] [4] when other, extinct groups are considered, the relationship between birds and crocodiles appears distant.
An example is thermo-regulation in Sauropsida, which is the clade containing the lizards, turtles, crocodiles, and birds. Lizards, turtles, and crocodiles are ectothermic (coldblooded), while birds are endothermic (warmblooded). Being coldblooded is symplesiomorphic for lizards, turtles, and crocodiles, but they do not form a clade, as ...