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

Explain about the transcellular route - calcium, Explain about the Transcel...

Explain about the Transcellular Route - Calcium? Transcellular Route: It operates primarily in the duodenum and proximal jejunum. It is stimulated when Ca ingestion is lower re

Invertebrate, classification of invertebrate

classification of invertebrate

Explain phylum zooflagellata, Phylum Zooflagellata (Animal Flagellates)...

Phylum Zooflagellata (Animal Flagellates) 1) At some stage of life-cycle they have one or more flagella. 2) They feed heterotrophically by absorption or phagocytosis, and

Nuclear type - endosperm, Nuclear Type - Endosperm The primary endosp...

Nuclear Type - Endosperm The primary endosperm nucleus divides. The cell wall is not laid. These nuclei and their division products form a large number of free nuclei. The fi

Define clinical progress for treatment for pem, Define Clinical progress fo...

Define Clinical progress for treatment for pem? Normally, clinical improvement is evident within a week with the disappearance of oedema, The appetite improves almost dramatica

Explain about vitamins, Vitamins Vitamins, as you may already know, der...

Vitamins Vitamins, as you may already know, derive its name from the word 'Vital Amine'. These are the organic compounds required for normal metabolism, growth and developme

What kind of structure is the crystalline lens, Q. What kind of structure i...

Q. What kind of structure is the crystalline lens? What is its function? The crystalline is a converging spherical lens this natural lens has the function to project images of

What is the role of vitamin k in the blood coagulation, Q. What is the orga...

Q. What is the organ where most of the clotting factors are produced? What is the role of vitamin K in the blood coagulation? Most of the clotting factors are produced in the l

Describe population and the frequency of the melanics, In one study of a he...

In one study of a heavily polluted area near Birmingham, England, a researcher observed a frequency of 87% melanic Biston betlularia. Calculate the frequency of the dominant allele

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