The rate at which organisms process energy and materials determines how fast they grow and reproduce, how long they live, and how rapidly they move through space. Thus it is not surprising that a number of key ecological traits depend on body mass and temperature. For example, John Damuth hypothesized that the maximal population abundance (or carrying capacity, large K) that a species can achieve is determined by how much energy is available (Efull) and how much energy is used by each private (Eindividual), so that Etotal is proportional to KEindividual. Because Eindividual is proportional to body mass raised to an exponent b (Mb where b ? 3/4), then Etotal is proportional to KM 3/4 , and K is proportional to EtotalM -3/4 .
This relationship, called the energy equivalence rule, tells you two things: 1. mice can reach higher abundances than elephants and 2. if the populations of elephants and mice are at their carrying capacity, these populations will use the same amount of energy (KEindividual is proportional M -3/4 + 3/4 = M 0 ). The relationship works well when a large number of species, including a very broad range of body sizes from all over the globe, are plotted together, probably because a sufficiently large number of species close to their carrying capacity are represented.
As the, during the certain site, not all variety is within holding strength, the fresh wealth to help you human anatomy mass matchmaking will have lots of spread out, and its own exponent may not be -3/cuatro
Another important ecological trait that is influenced by body size and temperature is rmax, the intrinsic rate of population increase (i.e., the rate at which populations can grow in the absence of food or space limitations). We have known for a very long time that populations of small animals can grow faster than those of large ones. More precisely, ecologists found that rmax is proportional to M -b . In 1974, Tom Fenchel conjectured that the value of rmax would be set by the organism’s mass-specific metabolic rate (i.e., the ratio of metabolic rate to body mass), and hence that b should be about -0.25. In 2004, Vance Savage and his collaborators hypothesized that rmax would depend on both body mass and temperature. Both conjectures proved to be roughly correct (Figure 5). Both the maximal rates at which populations can grow and their potential carrying capacity are influenced by body size and temperature. Ecologists have documented similar effects for processes as disparate in scale as molecules evolving, and the flow of energy and materials through ecosystems. Temperature and size affect how organisms work because organisms cannot break the limits imposed on them by physics and chemistry. The physical and chemical principles that rule the transfer of energy and materials within and among organisms generate order in the riotous, and sometimes seemingly overwhelming, complexity of ecological systems.
Records and Demanded Discovering
Frazier, Yards., Huey, Roentgen. B. ainsi que al. Thermodynamics constrains https://hookupdaddy.net/ios-hookup-apps/ the fresh new advancement off insect population increases pricing: “hotter is the best”. American Naturalist 168, 512–520 (2006).
Gillooly, J. F., Brown, J. H. ainsi que al. Negative effects of size and you will temperatures into kcalorie burning. Technology 293, 2248–2251 (2001).
Into the Data 2 and you may step three, points away from 10 over the axes is separated from the same distance: a hundred kilogram can be as away from 10 kilogram because ten kilogram try from 1 kilogram. Which, we find that lots of options that come with dogs and you will herbs one interest ecologists are different while the fuel services from looks size. The research of these relationship is called allometry plus the equations you to definitely associate an enthusiastic organism’s element which have human anatomy mass are known as allometric equations (regarding Greek origins allo meaning that “other” and you may meter which means that “measure”). When organisms obey the main out of mathematical similarity demonstrated more than, upcoming we consider the partnership between a characteristic and the body bulk just like the isometric. For example, the connection ranging from surface area and body size try isometric.