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FAQs on New Species
by Emilio Garcia

How Do New Species Occur?
In l942 E. Mayr published the classic book, Systematics and the Origin of Species. In it he states that there have to exist two factors for speciation: "the development of diversity and the establishment of discontinuity between diverging forms." Although geographic isolation is the more common means of establishing discontinuity between populations, Mayer later observes that changes in ecology and/or reproductive patterns may also contribute to the process of speciation.

What Is A New Species?
It is the problem of those who describe new species, the taxonomists, to decide if the differences in populations due to geographic or ecological isolation are sufficient to have created a new species. The act of describing the new species, therefore, indicates that the taxonomist has reached the conclusion that they are sufficient.
Many species have specific differences from all others. However, with closely related species, extremely similar in appearance, the taxonomist ideally will have to inspect the original material from which each related species was described before reaching a final decision. Furthermore, the taxonomist should have access to series of specimens of the species that have already been described to make sure that this new species does not fit into any of the variations of named species. Along this line, it is also preferable to have more than one specimen of the new species to be sure that one is not dealing only with a unique aberration. A good description of a new species will establish constant and clear differences between it and all other closely related species.

What is a subspecies?
When two or more populations of a species are geographically isolated and show consistent differences between them, they are given subspecific names. For example, there is a population of the spider conch Lambis crocata that inhabits the Marquesas Islands. The specimens are much larger than those of contiguous populations. The population is called Lambis crocata pilsbryi. Therefore, the species Lambis crocata is divided into two subspecies: Lambis crocata crocata and Lambis crocata pilsbryi. Many taxonomists no longer accept the validity of a subspecies, arguing that the isolated populations have either become different species or are only forms of the original species and therefore have no taxonomic validity.

Holotypes and paratypes:
The author of a new species will choose a single specimen which he considers to be the best representative of the species he is describing, and he will name it the holotype. Then he may choose other specimens from the type series that will reinforce the understanding of the species, and he will name them paratypes. After the species is published, anyone who wants to describe a new species closely related to this one, or who wants to question the validity of the new species, will have to consult this type material. Holotypes and paratypes should be deposited in public institutions so that they are readily accessible to any worker who needs to inspect them.

Lumpers and splitters:
Many species described in the past as new were later found to be only forms of species already described. At times, everyone agrees; at other times, however, the relationship between very closely related species is not clear and taxonomists (and amateur collectors) disagree as to whether a certain species is valid or only a form of an already described species. Those who think that the differences between two or more species are minor and that they all should be treated as one are called lumpers, and those who think the differences, and thus the species, are valid are called splitters. Such controversies are more prevalent with popular families such as Cypraeidae (cowries), Conidae (cones), Volutidae (volutes) and Muricidae (murex and rock shells).

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