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

Calculate how much of the absorbance of the bsa, For a sample containing bo...

For a sample containing both protein and nucleic acid, the absorbance measured at a particular wavelenght will be the sum of contributions from both types of molecule. using the pr

When to use the term 2'' carbon, When do you use the term 2' carbon and whe...

When do you use the term 2' carbon and when do you use 2 carbons on a molecular structure? I need examples please!

Types of retaining structure, What are the types of evaluation of lateral e...

What are the types of evaluation of lateral earth forces acting on retaining structures? This section seeks to introduce you to the evaluation of lateral earth forces acting on

Hydra – metazoa, Hydra – Metazoa The animals of phyla Cnidaria and Cte...

Hydra – Metazoa The animals of phyla Cnidaria and Ctenophora are made up of only two germ layers: ectoderm which forms the outer covering of the animal and endoderm which is t

Normal color vision- color blindness, If a color blind man marries a woman ...

If a color blind man marries a woman pure for normal color vision, it's probable that one of the below situations may result. Is it possible that a) All the children would be

What is cost effective analysis, What is Cost Effective Analysis? Cost ...

What is Cost Effective Analysis? Cost effective analysis: Cost effective analysis provides for the choice of least expensive strategy at the least cost. Here the outcome is mea

What is catabolism, Q. what is Catabolism? Catabolism is a process of b...

Q. what is Catabolism? Catabolism is a process of breaking down large or complex molecules of food components into smaller components. These supply energy to the cell in a form

Explain the penicillium - fungi, Explain the Penicillium - Fungi? Class...

Explain the Penicillium - Fungi? Classification Kingdom - Mycetae Division - Amastigomycota Class - Ascomycetes Subclass - Plectomycetidae Order - Eurotiales

Explain the term direct calorimetry, Explain the term Direct Calorimetry? ...

Explain the term Direct Calorimetry? Calorimetry refers to the measurement of the amount of heat evolved or absorbed in a chemical reaction, change of state, or formation of a

Types of variations, Types of Variations - Somatogenic and Blastogenic...

Types of Variations - Somatogenic and Blastogenic Variation Changes in somatic parts of the body are somatic variations e.g. wrestler's muscle, circumcised penis of mus

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