Speciation, Biology

Assignment Help:

Ernst Mayr, for whom, species and species problem have been the main concern of research, points out that speciation, the multiplication of species, that is division of one parent species into several daughter species is one process responsible for the evolutionary diversity of organic world. Darwin no where in his book Origin of Species defined the word species precisely although he interpreted speciation in terrns of reproductive isolation (Darwin again did not use the term reproductive isolation in his book.) Darwin did en~phasise that occupation of an unique ecological niche by each species could be a major characteristic of speciation. In this unit we shall briefly analyse the species concept laying emphasis on biological species and discuss in detail different types of mechanisms of speciation. Further we shall briefly look into how isolation brings about genetic repatterning and proceed to discuss the mechanisms of isolation with well chosen examples. As an illustration of how isolating mechanisms develop gradually, we shall explain the concept of ring species - the evolution of distinct new species. Finally there will also be a discussion on a phenomenon called genetic drift which however has no causal connection with speciation process but explains that in peripheral isolates gene frequencies drift due smapling error.


Related Discussions:- Speciation

Organ that belongs to more than one organ system, What is an organ that bel...

What is an organ that belongs to more than one organ system? One answer is the pancreas. It belongs to both the endocrine and digestive systems. Another one is bone marrow. It

Renal parenchymal disease, Renal parenchymal disease is the commonest cause...

Renal parenchymal disease is the commonest cause of secondary hypertension.  Hypertensive and diabetic nephropathy and chronic glomerulonephritis are the main causes. Eventually, t

Treatment and nursing management of cleft lip, Treatment and Nursing Manage...

Treatment and Nursing Management The initial treatment is surgical repair of  the cleft. The timing of the repair varies from surgeon to surgeon, but most prefer cleft lip rep

Strawberry slain - common disorders of skin, Strawberry Slain: It  sig...

Strawberry Slain: It  signfies the dilatation  of deeper vessels  to form  cavernous spaces like those seen  in  the erectile tissue of the penis. The  lesion  is well-defined

What is a chromosomal translocation, Question 1 Write a short note on the ...

Question 1 Write a short note on the following- Plasmids Retrotransposons Hfr Conjugation Generalized transduction Question 2 With the help of a neat diagra

Define aerobic respiration, Where in mitochondria does the process called r...

Where in mitochondria does the process called respiratory chain happen? Which are the products of the Krebs cycle used in that final phase of the aerobic respiration? Respirat

Mechanism of regulation, A number of protein-coding genes are active in all...

A number of protein-coding genes are active in all cells and are required for so- called house-keeping functions such as the enzymes of glycolysis, the citric acid cycle and the pr

Analytic characters - nature and structure of community, Analytic Character...

Analytic Characters - Nature and Structure of Community As you know a community has its own characteristics. Which are not shown by its individual component species. These cha

Define physiology cohesion and adhesion theory, Define Physiology: Cohesion...

Define Physiology: Cohesion & Adhesion Theory? Transport in Plants :  Transport of water, minerals and nutrients within vascular plants is dramatically different from animals

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd