Population regulation, Biology

Assignment Help:

Population Regulation

The number of individuals in a natural population varies with time. If the size of a population declines too drastically due to some reason, it may become extinct, but may later be re-established by immigration from other populations. On the other hand, increase in size of a population is not infinite since the carrying capacity of the environment always imposes a restriction upon it. In spite of such fluctuations, however, an outstanding feature of most large populations is that their average size changes relatively little over the years and certainly less than is expected from their biotic potentials. This indicates that population sizes are regulated in such a way that small population grow fast, larger populations grow more slowly and still larger populations decline.

Let us see what brings about such ecological homeostasis. In low-diversity, physically stressed ecosystems or in those subjected to irregular or unpredictable external perturbations, populations tend to be regulated by physical components such as weather, water, chemical limiting factors, pollution etc. In high diversity ecosystems, or in those which are not physically stressed, populations tend to be biologically controlled. In all ecosystems there is a strong tendency for all populations to evolve through natural selection towards self-regulation such as failure of reproduction and self-inflicted mortality. Even though this is difficult to achieve under external stress. It is because over-population is not in best interests of any population. Thus it can be said that limitation of number in any population is brought about by the action and interaction of two basic regulatory processes namely density dependent and density independent factors. We will discuss these processes in the following subsections.


Related Discussions:- Population regulation

How cholera is generally spread in humans, How cholera is generally spread ...

How cholera is generally spread in humans Associated Foods: Cholera is generally a disease spread by poor sanitation, resulting in contaminated water supplies. Sporadic cases o

Phanerophytes - classes of life form, Phanerophytes - Classes of Life Form ...

Phanerophytes - Classes of Life Form The perennating buds in this case are present on erect, negatively geotropic shoots, much above the ground. These buds are naked or least

Explain restriction endonucleases are enzymes, Restriction endonucleases ar...

Restriction endonucleases are enzymes which: 1. make cuts at specific positions within the DNA molecule 2. recognize a specific nucleotide sequence for binding of DNA ligase

Clinical manifestation and diagnosis of pericardiocentesis, Clinical Manife...

Clinical Manifestation Occurs over an extended time period and mimic those of CHF and corpulmonale. Dyspnea on exertion, dependent odema, ascitis, fatigue, anorexia and weight

Indirect routes of disease transmission, Question 1: Define Survey. Lis...

Question 1: Define Survey. List out advantages of surveys. Brief up different survey methods Definition of survey. Advantages of surveys Different survey methods

Illustrate stage of cellular respiration, Q. What is the stage of cellular ...

Q. What is the stage of cellular respiration during which carbon dioxide is liberated? In aerobic cellular respiration the release of carbon dioxide happens in the transformati

Pathophysiology of endocrine system, What is the relation between posterior...

What is the relation between posterior pituitary gland and diabetes insipidus?

Define food business and food technology, Define Food Business and Food Tec...

Define Food Business and Food Technology? The food business and food technology are practically inseparable. The food business may be characterized as: vulnerable to spoilage,

Cell theory, Cell Theory The term cell was first used by an English cyt...

Cell Theory The term cell was first used by an English cytologist, Robert Hooke (1665) not for unit protoplasmic masses, but for the well defined and empty compartments, he obs

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