The Pyramid of Number is one of three types of ecological pyramids.
Ecological pyramids depict the quantity of energy or matter contained within each trophic level of a food chain or food web. Pyramids of energy, biomass, and numbers are the three types. 15.8 million years ago, during the Miocene period, there was an explosion of diversity in animals, with many new species appearing almost immediately after the extinction of the dinosaurs. This is known as the Cenozoic Era Discovery! Scientists think that this explosive diversification may have been caused by changes in climate that allowed for new habitats to develop, which in turn gave rise to different kinds of organisms. For example, insects began to dominate the landscape once more after being absent for about 95% of history of life on Earth. Ancient Egyptians would have recognized these ecological pyramids as representations of their society. The pyramids were made up of three parts: a base, a pyramid, and a top. The bases were probably made of stone or clay and could be flat or shaped like a cake pan. The pyramids themselves were usually built out of rock or soil piled up on the foundation- sometimes including some pieces of wood or metal- and held together with plaster or mortar. At the top of the pyramid was a flat surface called the apex. It might be decorated with stones or other materials such as feathers.
A number pyramid depicts the total number of individual creatures at each level of an ecosystem's food chain. Because the biomass of the creatures is not taken into consideration, a pyramid of numbers does not necessarily have a regular pyramid form. The diagram on the left shows a number chain with 10 links and the right diagram shows a triangle pyramid with the same number of links.
The word "pyramid" comes from the Greek words pyr meaning fire and massa meaning heap. Thus, a pyramid is a heaped-up pile of burning coal or wood. In ancient Egypt, pyramids were used as tombs for pharaohs and their servants. They are shaped like small mountains, with the narrow end toward the sky and the wide end down toward the horizon. There are actually two types of pyramids: those without any openings and those that contain one central chamber with air holes leading to inner passageways called corbelling.
In biology, a pyramid structure is a complex organism containing several compartments, such as myriads of cells within an animal body or plants within a tissue. Biological pyramids are important because they provide protection against damage and death of some of the components if others are damaged or killed. For example, if all the bone marrow was removed from blood vessels, then the body would quickly die from lack of blood cells.
Biomass pyramids are typically more better at displaying the concept of energy loss as you move down the food chain. Pyramids have the form they do because energy is wasted at each trophic level. Only a portion of the energy is available to be transmitted down the food chain at each trophic level. For example, only 10% of the solar energy that reaches the surface of the earth is actually used by plants for growth. The rest is lost through radiation into space or consumed by other organisms.
When we talk about biomass pyramids, we are talking about the relationship between body mass and different measures of organ size. Scientists use the term "pyramid" to describe how organs scale with respect to body mass in mammals. The three main types of biomass pyramids are the metabolic pyramid, the structural pyramid, and the evolutionary pyramid.
Metabolic pyramids show the relative sizes of various organs when expressed on a per unit of body mass basis. The heart is usually the largest organ in metabolic pyramids, followed by the brain and then the lungs. Other major organs include the liver, kidneys, muscles, and bones.
Structural pyramids show the relative sizes of various organs when expressed in terms of total body weight. The heart is usually the largest organ in structural pyramids, followed by the lungs and then the brain. Other major organs include the liver, muscles, and bones.