PinkMonkey Online Study Guide-Biology
13.1 Concept of Species
The original concept of species has undergone a considerable
change during the progress of taxonomy. John Ray (1627-1705) was the first
to distinguish genus and species. However, the clear morphological concept
of species was first given by Linnaeus (1707-1778). Later on, Darwin proposed
the biological concept of species. The concept was further modified by
Morphological concept of species by Linnaeus.
A species is the group of individual which resemble each other in most
major morphological (vegetative and reproductive) characteristics.
Biological concept of species by Darwin. In addition to morphology, the biological concept also takes into consideration ecology, geography, cytology, physiology, behavior, etc.
According to the biological concept, a species is a group
of individuals which resemble each other in morphological, physiological,
biochemical, and behavioral characteristics. These individuals are capable
of breeding with each other under natural conditions, but are unable to
breed successfully with members of other species.
Thus, species is a group of fertile organisms that can interbreed and produce fertile offspring only among themselves.
The recent trend is to consider species as the groups of actually or potentially interbreeding natural populations of closely resembling individuals (Ernst Meyr).
A species is considered to be the smallest, most basic
unit of classification in most of the systems. It was thought to be an
indivisible, stable and static unit (taxon). However, in modern taxonomy,
sub-divisions of species, such as sub-species and populations, have been
created which aid in our understanding through classification.