Speciation, Biology

Assignment Help:

SPECIATION -

  • Origin of new species: An isolated population of a species independently develops different types of mutations.
  • The later accumulate in its gene pool. After several generations, the isolated population becomes genetically and reproductively different from others so as to constitute a new species.
  • The million of different species that exist today did not emerge by any single sequence of events but have come into existence by following types different paths of speciation.

1.       PHYLECTIC SPECIATION -

  • Darwin entitled his great book.
  • For Darwin, speciation was the simple, gradual accumulation of changes in a lineage throughout time, until the group was distinct enough to be considered a new species. This process is now called phyletic speciation.

2.       ALLOPATRIC SPECIATION -

  • It is considered as the most common type of speciation.
  • Allopatric speciation typically occurs when a physical barrier i. e., a mountain range, a river, or an oil pipeline, geographically separates a population from its parental population.
  • E.g., Different species of Darwin finches in the Galapagos Island.

3.       SYMPATRIC SPECIATION -

  • Sympatric speciation occurs in populations where individuals continue to live among one another, even though some type of biological difference, such as the time of the year when gonads mature, has divided the members into different reproductive groups.
  • The best accepted cases of sympatric speciation occur in plants as a result of polyploidy, an increase in the number of sets of chromosomes per cell occurs.

4.       PARAPATRIC SPECIATION -

  • Parapatric speciation is thought to occur in populations that lie adjacent to one another.
  • Gene pools diverge because the environment varies sufficiently in the different localities.
  • As a result, different traits are selected in each population.

Related Discussions:- Speciation

What is counsellor, Q. What is Counsellor? Counsellor is someone who gi...

Q. What is Counsellor? Counsellor is someone who gives advice about the problem. A counselor's role is to help patients help themselves. In our context  a counsellor is  a comm

What are phospholipids, What are phospholipids? Phospholipids are molec...

What are phospholipids? Phospholipids are molecules made of glycerol bound to two long molecules of fatty acids and to one phosphate group. Thus, phospholipids are amphipathic

List out points about the traditional food preservation, List out Points ab...

List out Points about the Traditional Food Preservation? 1. The traditional food preservation methods like drying, pickling, salting, smoking, canning and freezing have been wi

Describe casparian strip, Casparian strip  In plants, the impermeable waxy ...

Casparian strip  In plants, the impermeable waxy layer between the cells of endodermis which stops water and solutes from entering into the xylem, except by passing through the cyt

What is osmotic pressure, Q. What is Osmotic Pressure? Ans. Import...

Q. What is Osmotic Pressure? Ans. Important characteristic of a cell is 'osmosis'. You would recall reading about osmosis in the Applied Physiology Course in Unit 8. I

Target organ damage, Central Nervous System   Hypertension is one of th...

Central Nervous System   Hypertension is one of the leading causes of cerebrovascular disease. It has been associated with accelerated age related cognitive decline. The most d

Define procedure for testing the presence of urea in milk, Define Procedure...

Define Procedure for Testing the Presence of Urea in Milk? 1. To 0.5 ml of milk add 0.5 ml of  DMAB solution  (prepared by dissolving 0.4 gm of p-dimethyl amino benzaldehyde po

Define nutrient needs and recommended dietary intake, Define Nutrient Needs...

Define Nutrient Needs and Recommended Dietary Intake? Table depicts growth of normal well-to-do Indian children. Their intake is the criteria to assess nutrient requirements t

What is protein denaturation, What is protein denaturation? Is there any ch...

What is protein denaturation? Is there any change in the primary structure when a protein is denatured? Secondary, tertiary and quaternary structures of proteins are spatial st

Determine the statement- the evolution of color vision, Based on your readi...

Based on your reading of the article entitled "The Evolution of Color Vision", which of the following is a false statement? A. Trichomatic vision is found in all male and femal

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