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

Palynofossils (microfossils), Palynofossil s (Microfossils) - Fossils ...

Palynofossil s (Microfossils) - Fossils of planktons, diatoms, unicellular algae (diatoms) and shelled protozoans. (Heliozoans, Radiolarian and Foraminifera). Its finding in s

Explain about left cerebral hemisphere, How is it structurally explained th...

How is it structurally explained that the motor activity of the left side of the body is controlled by the right cerebral hemisphere and the motor activity of the right side of the

Find human anatomy & physiology laboratory manual, I can not find Human Ana...

I can not find Human Anatomy & Physiology Laboratory manual 10th edition cat version by Marieb/mitchell in expertsmind homework help, I have the text book just need to make sure I

Explain about salivary glands in humans, Q. What is the location of the sal...

Q. What is the location of the salivary glands in humans? There are six major salivary glands and they are located one in each parotid gland, two beneath the mandibles (submand

Differance among subphylum chaetognatha and urochordata, Explain differance...

Explain differance between Subphylum Chaetognatha and Subphylum Urochordata? Subphylum Chaetognatha: Larval stages of this small group share some of the characteristics with

Design a microcontroller-based system, Suppose you are in charge of designi...

Suppose you are in charge of designing a microcontroller-based system for a packet processing application. These are high speed internet packets from the PC that are going to be pr

Define intracellular fluid or the water within the cells, Define intracellu...

Define intracellular Fluid or the water within the cells? The intracellular Fluid or the water within the cells makes up about 40-4596 of the total body weight. Because the bod

Explain about bt reassessment, Will the plant-incorporated protectants rule...

Will the plant-incorporated protectants rules affect the Bt reassessment? No. To make sure that our biotechnology assessments reflect the latest data on health and ecological e

Transgenics considered a threat to the environmental safety, Q. Why are tra...

Q. Why are transgenics considered a threat to the environmental safety? The Transgenics can be dangerous to the whole biosphere since the transfer of genes between species may

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