Describe and contrast 2 species definitions.
The species designation is one of the lower designations in terms of identifying organisms on the taxonomic scale. The organisms in a species are usually classified on the basis of identical DNA, so DNA would be one way to establish a species. A good example of this would be that human beings and chimpanzees share a 99% identity rating within their DNA structure. However, chimpanzees and humans do not have truly identical DNA, therefore not only are they separated into different species, but into different genus categories as well; chimpanzees are classified as either Pan troglodytes or Pan paniscus, while the taxonomy for modern humans is Homo sapiens sapiens.
Another way to identify organisms, so as to classify them into a category of species, would be to identify by phenotypical structure. This is quite useful in the establishment of plant species, say by identifying similar flower structure. Butter cups, the flowers that herald the arrival of spring are all very similar in their structure, but have differences within the structure of their design and color.
A species is a subdivision of a genus. Members of a species can interbreed and produce fertile offspring, resemble one another and are not able to breed with members of a different species. A different definition states that a species is one of the basic units of biological classification. In taxonomy, living things are given a genus and species name. This designation is known as binomial nomenclature. For example, the genus Canis includes various species of animals including dogs, wolves, coyotes among others. Wolves are placed in Canis lupus and coyotes are placed in Canis latrans. Both are in the same genus Canis, but are classified as different species. This indicates common ancestry in the past that diverged into the various species of Canis, that exist today. By definition however, only members of a given species can produce fertile offspring when they breed. Sometimes, closely related individuals mate(as in donkey and horse) and they produce a mule. However, mules are sterile, therefore, donkey and horse are classified as different species.