The evolutionary species concept was developed by Simpson in 1951 to include asexual organisms and extinct species because the biological species concept could not be applied. The problem arises when the evolutionary species concept was seen in the gaps in the fossil, especially the particular ones experiencing regular size or shape evolution.
Simpson’s definition of a species is modified to state: a species is a lineage of ancestral descendant populations which tends to maintain their own identity from other such ancestry and which goes through its evolutionary tendencies and historical fate.
This particular definition is that it has the widest theoretical information given in the current knowledge evolutionary process. Four after-effects are concluded and discussed in other concepts
- all organisms, past and present, belong to some evolutionary species;
- reproductive isolation must be effective enough to permit maintenance of identity from another contemporary ancestry
- morphological distinctiveness is not necessary
- no presumed (hypothesized) single lineage may be subdivided into a series of ancestral “species.
Simpson in 1951
George Gaylord Simpson was a scientist who made enduring contributions to countless fields of study. However, the ideas resulting from his discoveries as a geologist and paleontology drive the field of evolution to this extent today. George Gaylord Simpson was a frail and small child growing up in Denver with his family. From 1918 to 1922 Simpson studied at Colorado University, Boulder.
Simpson’s passion for geology and paleontology was encouraged by one of his early professors at the University of Colorado Arthur J. Tieje. However, it is known he never graduated from the University of Colorado. In 1927 he was appointed as an assistant curator at the American Museum of national history.
While working at the museum he was offered the opportunity of the job as a professor at the University of Colorado. Not like the fellow paleontologists he was working with, he was able to recognize the role of genetics in evolutionary theory.
His work ‘Tempo and Mode in evolution’ developed the new evolutionary species concept. In his work ‘Tempo and Mode in evolution,’ he made various arguments about evolution and gave a new idea known as quantum evolution. He argued that all these rates of evolution were all due to the result of genetic change in the population.
Evolutionary species concept limitations
The application of the evolutionary species concept to allopathic demes and for the case of the asexual species is discussed and then concluded that the lack of evolutionary divergence forms the basis for grouping such populations into a single species. Due to the rate of extinction of some ecological species, definitions lead to under such estimations.
The other thing responsible for these estimations is the logical framework that excludes unsuccessful species from being species. Defining and recognizing a species has been a controversial issue for a long time. To determine the variation and the limitation between species, many concepts have been proposed. When a particular taxon is being studied by a taxonomist, a species concept must be adopted by him or her to provide a species limitation to define the particular taxon. Positive and negative aspects are represented as their addition to the application.
Species are one of the basic units to compare in almost all fields of biology, derived from anatomy to behavior, development, and also ecology. Evolutionary species concept examples are evolution, genetics, molecular biology, paleontology, physiology, and systematic. The term species has different meanings for various botanists including systematizes as well as taxonomists. The main recent issue in the field of biological systems is to develop any theory to lead the taxonomic practices in building a tenacious biological classification.
The fossil record
The study of paleontology is to recover and study the Fossil remains of thousands of organisms that lived in the past. It is shown in fossil records that many varieties of organisms that are extinct now were quite different in form than the ones that are living now. It also showcases the succession or evolution of organisms through time, their transition from one form to another. When an organism dies, it gets destroyed by other life forms and also by the process of weathering.
Only in some or rare cases some body parts or the organisms ( like hard parts mainly made of calcium ones such as shells, teeth, or bones) are conserved by being buried in mud or protected from other animals such as predators and also by natural factors.
Eventually, the dead bodies get petrified and are preserved well in the rocks or soil where they get embedded into those rocks. Using the same process the paleontologists have recovered various fossils and then reconstructed them to get examples of radical evolutionary transitions in both forms and their body functions. For example, the lower jaw of reptiles consists of several bones, but mammals have only one. The other bones in the reptile jaw were then unmistakably evolved into bones now found in the mammalian ear.
Conclusion
The whole concept of species as taxa was adopted by a known investigator who influenced his point of view on the processes by which the species originate. The concept adopted by him should be applied universally as current knowledge permits. It should not be expected that all members of a species be identical, so we ought to consider what immense and types of differences there are between individuals which will lead our way to discover a completely different organism.
Three species will be considered here that are vastly used by scientists, well all the species will be provided with limitations and also better in the field of functioning for some organismal groups than others.