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

Instrument examination and care, Instrument Examination and Care Cleani...

Instrument Examination and Care Cleaning instruments, provides a good opportunity to examine, replace or remove damaged instruments; lubricate items such as handpieces; and oth

Describe the need for harmonization in clinical trials, Question 1: Des...

Question 1: Describe the need for Harmonization in clinical trials? Brief on the Revised ICH terms of reference and explain the structure of ICH? Need for Harmonization i

Safety measures in the administration of drugs, SAFETY MEASURES IN THE ADMI...

SAFETY MEASURES IN THE ADMINISTRATION OF DRUGS It is essential to revise the five "Rights" before administration of medication to the paediatric group. These as you know are:

Interspecific competition, Darwin while evolving the concept of natural sel...

Darwin while evolving the concept of natural selection laid emphasis on competition among individuals belonging to a species, that is intraspecific competition. Here the individual

What is the life cycle of the gymnosperms, What is the life cycle of the gy...

What is the life cycle of the gymnosperms? As all plants they show a diplobiontic life cycle, i.e., alternation of generations with diploid and haploid stages. The lasting (fin

Diagnosis and management of cancer lung, Diagnosis Chest X-ray, Sp...

Diagnosis Chest X-ray, Sputum Cytology Test  Fibro Optic Bronchoscopy and Biopsy  In later stage of disease - weight loss, Debility indicating metastasis Staging of

Giardia – flagellates, Giardia – Flagellates Giardia intestinalis inha...

Giardia – Flagellates Giardia intestinalis inhabits the intestine of man. It has the distinction of being probably the first parasitic protozoan to be seen by Antony Van Leeuw

Ecological isolation, Ecological isolation is based on the fact that popula...

Ecological isolation is based on the fact that population shows preference to one habitat over the other. This extensive forests become barriers to the dispersal of organims living

How do taenias classify according to the division of sexes, How do taenias ...

How do taenias classify according to the division of sexes? Taenias are monoecious (hermaphrodite), the similar individual has female and male reproductive organs and undergoes

Why the diluent is distilled water, A drug has a molec. weight of 200. How ...

A drug has a molec. weight of 200. How many grams would you use to make 100 ml of a solution that is isotonic (for man)? Assume that the diluent is distilled water and that the dru

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