Species concept, Biology

SPECIES CONCEPT -

  • According to Davis and Heywood species define as assemblage of individuals with morphological features in common and separable from other such assemblage by correlated morphological discontinuities in a number of features.
  • Lumpers tend to combine populations into single species or groups.
  • Splitters tend to separate the same populations into different species or groups.

BIOLOGICAL SPECIES CONCEPT -

  • A species is a sexually interbreeding or potentially interbreeding group of individuals separated from other species by reproductive isolation that is by absence of genetic exchange.

SIBLING SPECIES CONCEPT -

  • When the two species are morphologically almost identical but do not interbreed. e.g., Drosophila pseudoobscura¬†and Drosophila persimilis are two species, do not cross-fertilize.

POLYTYPIC SPECIES CONCEPT -

  • Morphologically and geographically separated species into a single species on the basis of their successful interbreeding is called polytypic species. e.g., North American sparrows - Passarella melodia.

EVOLUTIONARYCHRONO SPECIES CONCEPT -

  • According to George Gaylord Simpson (1961) A species as a group of organism that is derived from its ancestor by a process of slow, steady evolutionary change and is not regarded as members of the same species as its ancestor.
Posted Date: 10/9/2012 1:52:00 AM | Location : United States







Related Discussions:- Species concept, Assignment Help, Ask Question on Species concept, Get Answer, Expert's Help, Species concept Discussions

Write discussion on Species concept
Your posts are moderated
Related Questions
Explain the Toxicity of nicotinic acid? Although therapeutically useful in lowering serum cholesterol, administration of chronic high oral doses of nicotinic acid can lead to h

Evaluation This is the last step in nursing process. Throughout care, you constantly evaluate the progress the client has made towards reaching the pre-established goals/ ob

Q. Proteins requirement in dyslipidemia? Proteins: While the quantity of protein does not impose any significant impact on the serum lipoproteins, it is the quality of protein,

Steps for Conversion of food Conversion of food is done in four steps: 1) Ingestion, mastication and swallowing: Ingestion or taking in of food and mastication are done b

Why is there a concern on waste water?

Determine Food Sources of Zinc? Zinc is normally associated with the protein and/or nucleic acid fraction of foods. Thus, foods high in proteins are good sources of zinc. Lean

Bacteria:- Advantages High yield of protein (60-80%) Can be grown on paraffin, cellulose waste and molasses. Growth rate is fast. Disadvantages  If the bacteri

Q. Requirements of various nutrients in constipation? The requirements of various nutrients are not altered in constipation. It is essentially a normal balanced diet (normal RD

a) The image above is part of a DNA sequencing gel. Assuming this is the DNA coding strand and you are reading 5' -> 3' what are ALL the possible polypeptides this sequence cou

Implementation The planned goals and strategies are translated into nursing intervention by means of the nursing care plan. It is essential that the client and family par