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

How did pasteur experiment vary from spallanzani, How did Pasteur's experim...

How did Pasteur's experiment vary from Spallanzani's experiment? Instead of sealing the flask in the experimental group after boiling, Pasteur used a flask with a curved neck,

How nutritional status influences the age, How nutritional status influence...

How nutritional status influences the age? The nutritional status influences the age-related rate of functional decline in many organ systems in the body. Nutrition is also an

Explain about the kwashiorkor - protein energy malnutrition, Explain about ...

Explain about the Kwashiorkor - protein energy malnutrition? Kwashiorkor is an African word, meaning a "disease of the displaced child", who is deprived of adequate nutrition.

Explain disease jet lag, Jet Lag   Disturbance of body and environmental...

Jet Lag   Disturbance of body and environmental rhythms resulting from a rapid change in time zones gives rise to jet lag, which is characterized by insomnia, decreased quality

Aschelminthes, In what part of the human body ASchelminthes found?

In what part of the human body ASchelminthes found?

Heparinisation, Heparinisation Blood when allowed to flow out from ...

Heparinisation Blood when allowed to flow out from body to the circuit tubings can get clotted. To prevent this, heparinisation is done. Patient is administered 3 mg

Which responds to electrical signals, You have identified a protein in a ce...

You have identified a protein in a cell that you know that comes from the human body. With respect to that protein you have also determined that it allows sodium ions to go through

RDA.., formulation of RDA

formulation of RDA

Define fermented dairy products-cheese, Normal 0 false false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

What are muscle tissues, What are muscle tissues? How is the function of th...

What are muscle tissues? How is the function of this tissue related to the typical characteristics of its cells? Muscle tissues are tissues made of cells able to perform contr

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