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

Heart, about of moving blood

about of moving blood

ANIMAL TRANSPORT SYSTEM, WWHAT ARE THE ORGANS THAT ARE INVOLVDED IN THE TRA...

WWHAT ARE THE ORGANS THAT ARE INVOLVDED IN THE TRANSPORTTATION SYSTEM OF ANIMALS

What do you mean by neuronal repolarization, Q. In chemical terms how is th...

Q. In chemical terms how is the neuronal repolarization achieved? Repolarization is the return of the membrane probable from the action potential (+35 mV) to the resting potent

Define vitamins and minerals needs in nutrient requirement, Define Vitamins...

Define Vitamins and Minerals needs in Nutrient Requirement and Dietary Management Although the exact requirements are not known, it is generally recommended to give plenty of f

What are fibroids, Fibroids, also called as leiomyomas, are benign smooth m...

Fibroids, also called as leiomyomas, are benign smooth muscle tumors that happen in the uterus. They grow under the influence of estrogen and progesterone, and are therefore seen i

Community gradients and boundaries, Community Gradients and Boundaries ...

Community Gradients and Boundaries It is often difficult or impossible to determine where one community ends and the next begins. Many communities, in fact, grade continuousl

Define composition of the diet during pregnancy period, Define composition ...

Define composition of the diet during pregnancy period? The composition of the diet during pregnancy should be the same as for a non- pregnant woman; hence the contribution to

What does boiling do to an enzyme, What does boiling do to an enzyme? Enz...

What does boiling do to an enzyme? Enzymes are denatured (their shape is changed so it doesn't work) when boiled.

Determine the meaning of response cost, Determine the meaning of Response c...

Determine the meaning of Response cost This is a type of punishment in which the subject has to return back the token (positive reinforcement) earned earlier if the subject dis

Define about the sucrose and trehalose, Define about the Sucrose and Trehal...

Define about the Sucrose and Trehalose? Sucrose, also called saccharose, is ordinary table sugar refined from sugar cane or sugar beets. Trehalose has two a-D-glucose molecu

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