What is the difference between monophyletic and polyphyletic?

in biological taxonomy - also called scientific classification or biological classification - a monofyně means that the group includes exclusively the species and all its ancestors, while polyphically means that the group can contain a "bag" of various families. These are called monophyletic and polyphyletic groups. An example of a polyphyletic group would be "worms" or "warm -blooded animals", while the monophyletic group would be "mammals" or "crustaceans". Since the 1970s of the 20th century, it was much easier by genetic methods - also called phylogenetic analysis or "molecular studies" - which study similar lengths of DNA to see how the animals are interrelated. Many groups that look superficially similar can be completely unrelated in practice. For example, pygopodidae, a family of element lizards, appear to be similar to toos, but they differ from them with eye eyelids that flash (which are missing), external holes for ears, flat, prevented tongues and residual limbs. For an amateur can be a tongue of divisionsTo be somewhat difficult, but it may be clear to a professional biologist.

One of the most standard examples of polyphyletic groups is warm -blooded animals, including both birds and mammals. Both species have a common predecessor who lived during a paleozoic long long ago. Birds, although distortion, have evolved from cold -blooded ancestors, dinosaurs who are hardly monophyletic in mammals. Birds and mammals are therefore from completely different groups, but both fall into the general category of warm animals.

specific biological taxonomy is the aim of taxonomists, but often contrary to common wisdom or lack of rigor. For example, when you ask, "Are there sea insects?" Some mod answer: "Well, certainly, the lobsters are like insects." Although for an occasional observer, this response might seem sufficient, it is enough to cause a career taxonoma to virtually spit its coffee.

IncorporatesZ are members of the insecta class, while the lobsters are a member of the Subhylum Crustacea, completely different groups. Although both are arthropods and are probably relatives, groups are completely different, one is primarily earthly and the other water. They are constantly referred to as a monophyletic group, a type of custom that taxonomists fight by being more specific about relationships between animals, which helps us better understand.