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 the importance of the auxin, a) How is the milk production regulate...

a) How is the milk production regulated by hormones in human female? Define. b) Explain the importance of the auxin / cytokinin ratio in plant tissue culture.

Obelia, what are the economic importance of obelia?

what are the economic importance of obelia?

Illustrate target organs of the hormones, Q. What are target organs of the ...

Q. What are target organs of the hormones? Target tissues, Target organs and target cells are those specific organs, cells and tissues upon which each hormone produces and acts

Define male and female ascaris lumbricoides, Define Male and Female Ascaris...

Define Male and Female Ascaris Lumbricoides? Ascaris lumbricoides unlike most free-living nematodes and a large number of parasites of plants and animals are not tiny or micro

Agro industrial-processing of roughage, Processing of roughage Roughag...

Processing of roughage Roughages constitute the bulk of the ration of farm animals and these include green fodder (leguminous and non-leguminous), grasses, and various crop re

Define sterol regulatory element binding proteins (srebps), Define Sterol R...

Define Sterol Regulatory Element Binding Proteins (SREBPS)? These belong to a general family of transcription factors. They are synthesized as membrane embedded proteins in res

Human development, Human Development Human development is a continuous...

Human Development Human development is a continuous procedure that begins when the ovum from a female is fertilised via sperm from a male to form the zygote. Growth and differ

Explain about the cardiovascular and circulatory system, Explain about the ...

Explain about the Cardiovascular and Circulatory System? Aging affects the cardiac muscle causing a diminished resting cardiac output. The capacity of myocardium for cellula

What are taenias and diseases caused by them, Q. What are taenias? What are...

Q. What are taenias? What are the diseases caused by them? The Taenias, as well know as tapeworms, are platyhelminth animals (flatworms). The major diseases caused by taenias a

What is the formula of the net primary production, What is the formula of t...

What is the formula of the net primary production (NPP)? How does NPP relate to the energy pyramids? Net primary production is the gross main productivity less the organic mate

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