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 units are the nucleic acids constituted, Q. Of what units are the nucl...

Q. Of what units are the nucleic acids constituted? What are chemical entities that compose that unit? The Nucleic acids are formed by sequences of nucleotides. Nucleotides

Explain procedure for determination of the quality of milk, Explain Procedu...

Explain Procedure for Determination of the Quality of Milk? 1. Prepare methylene blue solution by dissolving 1 mg methylene blue in 250 ml of sterile distilled water. 2. Aft

Set up a potometer in the laboratory, A student set up a potometer in the l...

A student set up a potometer in the laboratory and measured the rate of movement of water in the capillary. An average of four readings gave a rate of 50mm per minute. The apparatu

What are protozoans? explain their functions, Protozoans are microscopic in...

Protozoans are microscopic in size however some are large enough to be seen with naked eye. Microscopic organisms such as these have numerous advantages, one of which is that they

Echinodermata - regeneration in invertebrates, Echinodermata - Regeneration...

Echinodermata - Regeneration in Invertebrates Asteroids (starfishes), ophiuroids (brittle stars) and crinoids (sea lilies) can reproduce their lost arms and although parts of

What is signifying by concentration gradient, Q What is signifying by conce...

Q What is signifying by concentration gradient? Is it correct or not to refer to "concentration gradient of water"? Concentration gradient is the variation of concentration of

Regeneration - development biology, Regeneration - Development Biology ...

Regeneration - Development Biology Regeneration has, intrigued scientists for several generations and has resulting in voluminous literature on the subject beginning from the

Empyema, Empyema: Empyema is accumulation of  thick pus in the pleural...

Empyema: Empyema is accumulation of  thick pus in the pleural cavity. Primary infection of pleura does not arise so the pathology may either be in chest wall, mediastinum or t

Give an example of structural protein, Give an example of each of the follo...

Give an example of each of the following types of proteins: a. Enzyme b. Structural protein c. Motor protein

Which kind of polarity do fat-soluble substance has, Q. Which kind of polar...

Q. Which kind of polarity do fat-soluble and water-soluble substances respectively have? Ans. Water-soluble substances are behave as polar molecules, i.e., they have e

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