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

How do white cells differ from red cells, How do white cells differ from re...

How do white cells differ from red cells (a) In their structure, (b) Their function?   a) White cells have nuclei, red cells do not have nucle

What is an immunotoxin, Immunotoxin is formed by conjugating or combining a...

Immunotoxin is formed by conjugating or combining an antibody with highly toxic agent.

Ice age, Ice age is an interval of geologic time between 2 million and 10,...

Ice age is an interval of geologic time between 2 million and 10,000 years ago during that period the northern hemisphere experienced several episodes of continental glacial advan

Introduction to fertilization, INTRODUCTIO N - Fertilization is a c...

INTRODUCTIO N - Fertilization is a complex process which involves fusion of male & female gametes. The male gamete in animals is called as sperm & the female gamete as o

Amphibia, what should i write in conclusion

what should i write in conclusion

Radiolarians - protozoan, Radiolarians - Protozoan Radiolarians are en...

Radiolarians - Protozoan Radiolarians are entirely marine planktonic species with spherical bodies and radiating pseudopodia known as axopods. The spherical body is divided in

State in brief about gullstrands theory, State in brief about Gullstrands T...

State in brief about Gullstrands Theory A change in the lens is controlled by the balance between elasticity of the lens capsule and the pull of zonules. It is believed that on

What are the main cellular functions of potassium, Q. What are the main cel...

Q. What are the main cellular functions of potassium? Moreover being important for the osmotic regulation and for the acid-base equilibrium (pH) potassium is fundamental for th

How many different types of pseudopods can amoebas have?, Tests of shelled ...

Tests of shelled amoebas are made from a variety of substances including sand grains, chitin and substrate, calcium salts, and even silica. These shells still accumulate in ocean d

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