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

Pressure gradient, Pressure Gradient You know that air pressure is the ...

Pressure Gradient You know that air pressure is the weight of the atmosphere over a unit area of the earth's surface. The average air pressure at sea level is approximately 1 k

What is polygenic inheritance?, What is polygenic inheritance? How does it ...

What is polygenic inheritance? How does it work?  The Polygenic inheritance, also called as quantitative inheritance, is the gene interaction in which a given trait is conditio

Procedure for spore staining in a given bacterial culture, Explain Procedur...

Explain Procedure for Spore Staining in a Given Bacterial Culture Carry out the exercise following the steps enumerated herewith 1. Take a clean, non-greasy slide. Prepare b

Rejection reaction, Rejection Reaction For rejection reaction the phys...

Rejection Reaction For rejection reaction the physiological and biochemical processes are set in the pistil by the recognition reaction specific to the type of pollen that lan

Explain what an isotonic fluid loss means, Your client has the flu and repo...

Your client has the flu and reports 5-6 loose stools a day. He has experienced an isotonic fluid volume loss. Explain what an isotonic fluid loss means. Your patient has a respi

Guess the number of different haploid cells, A diploid cell contains four p...

A diploid cell contains four pairs of homologous chromosomes designated C1 and C2, M1 and M2, S1 and S2, and W1 and W2. Predict the number of different haploid cells that could be

What is the significance of spicules, What is the significance of Spicules?...

What is the significance of Spicules? Any needlelike structure. This term is very often thought of in conjunction with sponges and refers to needlelike structures produced by s

When fecundation to be effective, Q. How long after ovulation must fecundat...

Q. How long after ovulation must fecundation occur to be effective? If fecundation doesn't occur around 24 hours after ovulation the released ovum often dies.

Arthropoda phylum, characteristic of spider that makes it the phylum arthro...

characteristic of spider that makes it the phylum arthropoda?

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