In evolutionary biology, evolutionary relay describes how independent species acquire similar characteristics as a result of their evolution in similar ecosystems, but not at the same time. Evolutionary biology is a subfield of biology concerned with the origin and descent of species, as well as their change over time, i. ...

A classic example is the dorsal fin of the extinct ichthyosaurs and the shark. Another example is the streamlined, fish-like shape of the ichthyosaurs and the shape of extant dolphins and small whales. Except for the tail fins, cetaceans greatly resemble fish in outline, but are instead descended from four-legged land mammals. Their closest land relative today is thought to be the hippopotamus. Their modern shape is due to their water-based life cycle, as is the shape of the fish. Dorsal Fin of the Orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins and porpoises. ... In biology and ecology, extinction is the ceasing of existence of a species or group of species. ... Ichthyosaurs (Greek for fish lizards) were giant marine reptiles that resemble a dolphin with teeth (see convergent evolution). ... Orders See Classification and Shark taxonomy Sharks are a group (superorder Selachimorpha) of fish, with a full cartilaginous skeleton, a streamlined body plan with between 5 and 7 gill slits along the sides (most often) or side of the head (the first modified slit is behind the eye and called... This article is about the dolphin mammal. ... Whales are the largest species of exclusively aquatic placental mammals, members of the order Cetacea, which also includes dolphins and porpoises. ... Suborders Mysticeti Odontoceti (see text) The order Cetacea includes whales, dolphins and porpoises. ... Atlantic herring, Clupea harengus, the most abundant fish species in the world. ... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals primarily characterized by the presence of mammary... they are fat friends ...

Evolutionary relay is a different phenomenon than convergent evolution and parallel evolution. In convergent evolution, independent organisms acquire similar characteristics while evolving in different habitats (e.g. bird and fly wings). Parallel evolution occurs when two independent species evolve together at the same time in the same ecospace and acquire similar characteristics (e.g. extinct browsing-horses and extinct paleotheres). In evolutionary biology, convergent evolution describes the process whereby organisms not closely related independently acquire similar characteristics while evolving in separate and sometimes varying ecosystems. ... In evolutionary biology, parallel evolution occurs when two independent species evolve together at the same time in the same ecospace and acquire similar characteristics. ... Orders Many - see section below. ... The Mediterranean fruit fly, or medfly, Ceratitis capitata A fly (plural flies) is any species of insect of the order Diptera, some of which can land on food and transmit bacteria to humans. ... The word wing or wings has more than one use: In aeronautics a wing is an apparatus used to create lift. ...

Related articles

Convergent evolution
Parallel evolution
Mimicry In evolutionary biology, convergent evolution describes the process whereby organisms not closely related independently acquire similar characteristics while evolving in separate and sometimes varying ecosystems. ... In evolutionary biology, parallel evolution occurs when two independent species evolve together at the same time in the same ecospace and acquire similar characteristics. ... A mimic is any species that has evolved to appear similar to another successful species in order to dupe predators into avoiding the mimic, or dupe prey into approaching the mimic. ...