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

Minimum difference in height among any two people, Suppose that there are s...

Suppose that there are six pairs of alleles which control height and that every dominant allele adds 5cm to the stature. Assume also that the average height of an adult (with equal

Explain about the zygomycota - fungi, Explain about the Zygomycota - Fungi?...

Explain about the Zygomycota - Fungi? Fungi belonging to zygomycota are called zygomycetes. Hyphae in this sub-class are coenocytic. Asexual spores develop in sporangia at the

Define typical structures of the seed and define endosperm, What are typica...

What are typical structures of the seed? What is the endosperm? A typical seed is the composed of the embryo, endosperm and shell. Inside seeds of angiosperms there are one or

Role of chemical factors in controlling apical dominance, Role of Chemical ...

Role of Chemical Factors in Controlling Apical Dominance There were indications about the existence of plant hormones in the last part of 19th century. The plant hormones had

How athletes benefit from consuming high carbohydrate foods, How Athletes b...

How Athletes benefit from consuming high carbohydrate foods? Athletes benefit from consuming high carbohydrate foods immediately after ending repeated intervals of intense exer

Body fluids – circulation, Normal 0 false false false E...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain major divisions of the hypophysis, Q. What are the major divisions ...

Q. What are the major divisions of the hypophysis? What are their functions? The hypophysis is divided into two portions- the anterior hypophysis or adenohypophysis and the pos

Explain the advantages of double beam method, Explain the Advantages of Dou...

Explain the Advantages of Double Beam Method? The double beam method has advantage over single beam as it automatically corrects, for the change in light transmission, through

When atp gives energy to the cellular metabolism, When ATP gives energy to ...

When ATP gives energy to the cellular metabolism it loses one of its phosphates and ADP reappears. ADP can also lose more phosphates and produce AMP (adenosine monophosphate) o

Define bitot''s spots - micronutrient deficiencies, Define Bitot's Spots - ...

Define Bitot's Spots - micronutrient deficiencies? As the deficiency progresses, dirty white, foamy and raised spots are formed on the surface of the conjunctiva, generally on

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