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

State the concepts of soil- pedology and edaphology, State the concespts of...

State the concespts of soil- pedology and edaphology In the last two centuries of scientific study, two concepts or approaches to the study of soil have evolved.  One called  p

Providing critical resources - conservation of wildlife, Providing Critical...

Providing Critical Resources - Conservation of Wildlife Another way to improve the habitat of a threatened species is to determine which resource is limiting the population si

Drug nomenclature, DRU G NOMENCLATURE - Generally drug has three types...

DRU G NOMENCLATURE - Generally drug has three types of names - Chemical, Proprietary & Non-proprietary. Chemical Name - Indicates chemical nature. Proprietary Name -

What are the symptoms of mitral stenosis, Q. What are the Symptoms of Mitra...

Q. What are the Symptoms of Mitral stenosis? The cardinal symptom of mitral stenosis is dyspnoea on exertion. Typically it progresses over a period of years. As the severity in

Practical preparation - qualitative test for monosaccharides, Define Practi...

Define Practical Preparation - Qualitative Test for Monosaccharides? 1. Wear your labcoat. Make sure your hair is tied and you have no loose clothing. These can be dangerous in

Explain virus envelope, Virus envelope is known as: 1.  Capsid 2.  Vi...

Virus envelope is known as: 1.  Capsid 2.  Virion 3.  Nucleoprotein 4.  Core Capsid

From which germ layer epidermis and nervous system originate, Q. From which...

Q. From which germ layer do the epidermis and the nervous system originate? What are other organs and tissues made from that germ layer? Epidermis and nervous system have the s

What is the physiological explanation for the daltonism, What is the type o...

What is the type of genetic inheritance of daltonism? Is daltonism more frequent in men or in women? What is the physiological explanation for the daltonism ? The Daltonism

What are the cell kinds that form the phloem, What are the cell kinds that ...

What are the cell kinds that form the phloem? What are the major features of those cells? The major cells that form the phloem are the sieve elements and the companion cells an

Colour coding rules for biomedical waste management, Q. Discuss the colour ...

Q. Discuss the colour coding rules for biomedical waste management and handling? Colour coding biomedical waste( management and handling) rules, 1998

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