Species and its criteria

BIOLOGY
a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g. Homo sapiens.

About 8.7 million (give or take 1.3 million) is the new, estimated total number of species on Earth -- the most precise calculation ever offered -- with 6.5 million species on land and 2.2 million in oceans. Announced by the Census of Marine Life, the figure is based on a new analytical technique.

FOR EXAMPLE:
Humans ( Homo sapiens ), moose ( Alces laces ), black bears ( Ursus americans ), jack pines ( Pinus banksiana ) are all examples of different species.

OLDEST LIVING SPECIES:
The horseshoe crab, nautilus, jellyfish, and sponge may be some of the oldest living animal species and the Gingko tree may be the oldest living plant species, but they're far from the oldest things found in the fossil record. Certain groups of bacteria have been around for billions of years.

Are dogs a species?
But among dogs, which are well known for their hybrid (or mongrel) varieties, different breeds can mate and have viable offspring, so they are all found under the umbrella of a single species, Canis familiaris. Dogs are highly unusual in their variation, from the Chihuahua to the Great Dane.

What are the 4 species concepts?
The important species concept are:
Typological or Essentialist Species Concept Nominalistic Species Concept
Biological Species Concept
Evolutionary Species Concept.

What is the best species concept?
The Biological Species Concept defines a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring. According to that concept, a species' integrity is maintained by interbreeding within a species as well as by reproductive barriers between organisms in different species.

STRUCTURE OF SPECIES:
1. The possible internal structures of species-lineages. In general, species consist of demes or habitat clusters, and comprise clades. A) A lineage consisting of a bundle of demes that oscillate through the phenotypic/habitat space of an established species but does not fill up the space, as in the other models.

POLYMORPHISM
Polymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object. Any Java object that can pass more than one IS-A test is considered to be polymorphic.

POLYMORPHISM IN LEPIDOPTERA