In polytypic species, the diagnosis of a subspecies is designed only to distinguish it from other subspecies of that species.
Isolation of some sort seems necessary to polytypic evolution.
A discussion of the polytypic species, Hypopachus oxyrrhinus, with a description of a new subspecies.
Duellman reviewed the species of the genus occurring in western Mxico and concluded that there were five species (two polytypic).
First, the distinction between monotypic and polytypic evolution is not defined.
Darwin was, therefore, of opinion that natural selection is able to bring about polytypic evolution.
Here we have what may perhaps be regarded as a glimmering of the distinction between monotypic and polytypic evolution.
It has been shown that divergent or polytypic evolution on common areas is inexplicable by natural selection alone.
Had he gone a step further, he must have seen that separation, in some form or another, is "indispensable" to polytypic evolution.
polytypic pol·y·typ·ic (pŏl'ē-tĭp'ĭk) or pol·y·typ·i·cal (-ĭ-kəl)
Having several variant forms, especially subspecies or varieties.
Having several variant forms, especially containing more than one taxonomic category of the next lower rank. A polytypic genus contains two or more different species, while a polytypic species consists of two or more subspecies. Compare monotypic.