Where is ecology found

This the Gaia hypothesis , [ 19 ] and is an example of holism applied in ecological theory. The Gaia hypothesis states that there is an emergent feedback loop generated by the metabolism of living organisms that maintains the temperature of the Earth and atmospheric conditions within a narrow self-regulating range of tolerance. Ecology and evolution are considered sister disciplines of the life sciences.

Natural selection, life history, development, adaptation, populations, and inheritance are examples of concepts that thread equally into ecological and evolutionary theory. In this framework, the analytical tools of ecologists and evolutionists overlap as they organize, classify and investigate life through common systematic principals, such as phylogenetics or the Linnaean system of taxonomy. Both disciplines discover and explain emergent and unique properties and processes operating across different spatial or temporal scales of organization.

All organisms are motile to some extent. Even plants express complex behavior, including memory and communication. Ethology is the study of observable movement or behaviour in nature. This could include investigations of motile sperm of plants, mobile phytoplankton, zooplankton swimming toward the female egg, the cultivation of fungi by weevils, the mating dance of a salamander, or social gatherings of amoeba.

Adaptation is the central unifying concept in behavioral ecology. Behaviors can be recorded as traits and inherited in much the same way that eye and hair color can.

Behaviours evolve and become adapted to the ecosystem because they are subject to the forces of natural selection. Predator-prey interactions are an introductory concept into food-web studies as well as behavioural ecology. Many prey species are faced with multiple predators that differ in the degree of danger posed.

To be adapted to their environment and face predatory threats, organisms must balance their energy budgets as they invest in different aspects of their life history, such as growth, feeding, mating, socializing, or modifying their habitat.

Hypotheses posited in behavioural ecology are generally based on adaptive principals of conservation, optimization or efficiency. The behaviour of long-toed salamanders Ambystoma macrodactylum presents an example in this context. When threatened, the long-toed salamander defends itself by waving its tail and secreting a white milky fluid.

Hence, salamanders subjected to frequent predatory attack will be energetically compromised as they use up their energy stores. Ecological interactions can be divided into host and associate relationships.

A host is any entity that harbors another that is called the associate. If the host and associate are physically connected, the relationship is called symbiosis. Symbiotic plants and fungi exchange carbohydrates for mineral nutrients.

For example, tropical rainforests regulate the Earth's atmosphere. Trees living in the equatorial regions of the planet supply oxygen into the atmosphere that sustains species living in distant polar regions of the planet.

This relationship is called commensalism because many other host species receive the benefits of clean air at no cost or harm to the associate tree species supplying the oxygen. Competition among species or among members of the same species is defined as reciprocal antagonism, such as grasses competing for growth space.

Intraspecific behaviours are notable in the social insects, slime moulds, social spiders, human society, and naked mole rats where eusocialism has evolved. Social behaviours include reciprocally beneficial behaviours among kin and nest mates. Kin selection explains altruism through genetic relationships, whereby an altruistic behaviour leading to death is rewarded by the survival of genetic copies distributed among surviving relatives.

The social insects, including ants, bees and wasps are most famously studied for this type of relationship because the male drones are clones that share the same genetic make-up as every other male in the colony.

Groups that are predominantely altruists beat groups that are predominantely selfish. A often quoted behavioural ecology hypothesis is known as Lack's brood reduction hypothesis named after David Lack.

Lack's hypothesis posits an evolutionary and ecological explanation as to why birds lay a series of eggs with an asynchronous delay leading to nestlings of mixed age and weights. According to Lack, this brood behaviour is an ecological insurance that allows the larger birds to survive in poor years and all birds to survive when food is plentiful. Elaborate sexual displays and posturing are encountered in the behavioural ecology of animals.

The birds of paradise, for example, display elaborate ornaments and song during courtship. These displays serve a dual purpose of signalling healthy or well-adapted individuals and good genes. The elaborate displays are driven by sexual selection as an advertisement of quality of traits among male suitors. The word biogeography is an amalgamation of biology and geography. Biogeography is the comparative study of the geographic distribution of organisms and the corresponding evolution of their traits in space and time.

For example, the theory of island biogeography, published by the mathematician Robert MacArthur and ecologist Edward O. Wilson in [ ] is considered one of the fundamentals of ecological theory. Biogeography has a long history in the natural sciences where questions arise concerning the spatial distribution of plants and animals.

Ecology and evolution provide the explanatory context for biogeographical studies. The splitting of lineages in a species is called vicariance biogeography and it is a sub-discipline of biogeography. For example, the range and distribution of biodiversity and invasive species responding to climate change is a serious concern and active area of research in context of global warming.

When an island is first colonized the density of individuals is low. The initial increase in population size is not limited by competition, which leaves an abundance of available resources for rapid population growth. These early phases of population growth experience density independent forces of natural selection, which is called r -selection.

When the population becomes crowded, it reaches the island's carrying capacity, and individuals compete more heavily for fewer available resources. Under crowded conditions the population experiences density-dependent forces of natural selection, called K -selection. An r -selected species is one that has high birth rates, low levels of parental investment, and high rates of mortality before individuals reach maturity.

Evolution favors high rates of fecundity in r -selected species. Many kinds of insects and invasive species exhibit r -selected characteristics. In contrast, a K -selected species has low rates of fecundity, high levels of parental investment in the young, and low rates of mortality as individuals mature. Humans and elephants are examples of species exhibiting K -selected characteristics, including longevity and efficiency in the conversion of more resources into fewer offspring.

The important relationship between ecology and genetic inheritance predates modern techniques for molecular analysis. Molecular ecological research became more feasible with the development of rapid and accessible genetic technologies, such as the polymerase chain reaction PCR. The rise of molecular technologies and influx of research questions into this new ecological field resulted in the publication Molecular Ecology in In , professor John Avise also played a leading role in this area of science with the publication of his book, Molecular Markers, Natural History and Evolution.

Molecular ecology engendered a new research paradigm to investigate ecological questions considered otherwise intractable. Molecular investigations revealed previously obscured details in the tiny intricacies of nature and improved resolution into probing questions about behavioral and biogeographical ecology. For example, molecular ecology revealed promiscuous sexual behavior and multiple male partners in tree swallows previously thought to be socially monogamous.

The environment is dynamically interlinked, imposed upon and constrains organisms at any time throughout their life cycle. Environment " The physical environment is external to the level of biological organization under investigation, including abiotic factors such as temperature, radiation, light, chemistry, climate and geology. The biotic environment includes genes, cells, organisms, members of the same species conspecifics and other species that share a habitat.

Armed with an understanding of metabolic and thermodynamic principles a complete accounting of energy and material flow can be traced through an ecosystem.

Environmental and ecological relations are studied through reference to conceptually manageable and isolated parts. However, once the effective environmental components are understood they conceptually link back together as a holocoenotic [ ] system. In other words, the organism and the environment form a dynamic whole or umwelt. Ecological studies are necessarily holistic as opposed to reductionistic. An example of the metaphysical aspect to holism is the trend of increased exterior thickness in shells of different species.

The reason for a thickness increase can be understood through reference to principals of natural selection via predation without any reference to the biomolecular properties of the exterior shells. Metabolism — the rate at which energy and material resources are taken up from the environment, transformed within an organism, and allocated to maintenance, growth and reproduction — is a fundamental physiological trait.

The Earth formed approximately 4. During this early Hadean period, the Earth started to cool, allowing a crust and oceans to form. Environmental conditions were unsuitable for the origins of life for the first billion years after the Earth formed. The Earth's atmosphere transformed from being dominated by hydrogen, to one composed mostly of methane and ammonia.

Over the next billion years the metabolic activity of life transformed the atmosphere to higher concentrations of carbon dioxide, nitrogen, and water vapor. These gases changed the way that light from the sun hit the Earth's surface and greenhouse effects trapped heat. There were untapped sources of free energy within the mixture of reducing and oxidizing gasses that set the stage for primitive ecosystems to evolve and, in turn, the atmosphere also evolved.

Throughout history, the Earth's atmosphere and biogeochemical cycles have been in a dynamic equilibrium with planetary ecosystems. The history is characterized by periods of significant transformation followed by millions of years of stability.

Early forms of fermentation also increased levels of atmospheric methane. The transition to an oxygen dominant atmosphere the Great Oxidation did not begin until approximately 2.

The biology of life operates within a certain range of temperatures. Heat is a form of energy that regulates temperature. Heat affects growth rates, activity, behavior and primary production. Temperature is largely dependent on the incidence of solar radiation.

The latitudinal and longitudinal spatial variation of temperature greatly affects climates and consequently the distribution of biodiversity and levels of primary production in different ecosystems or biomes across the planet. Heat and temperature relate importantly to metabolic activity. Poikilotherms, for example, have a body temperature that is largely regulated and dependent on the temperature of the external environment. In contrast, homeotherms regulate their internal body temperature by expending metabolic energy.

There is a relationship between light, primary production, and ecological energy budgets. Sunlight is the primary input of energy into the planet's ecosystems.

Light is composed of electromagnetic energy of different wavelengths. Radiant energy from the sun generates heat, provides photons of light measured as active energy in the chemical reactions of life, and also acts as a catalyst for genetic mutation. Organisms capable of assimilating energy by photosynthesis or through inorganic fixation of H 2 S are autotrophs. Autotrophs—responsible for primary production—assimilate light energy that becomes metabolically stored as potential energy in the form of biochemical enthalpic bonds.

Wetland conditions such as shallow water, high plant productivity, and anaerobic substrates provide a suitable environment for important physical, biological, and chemical processes. Because of these processes, wetlands play a vital role in global nutrient and element cycles.

The rate of diffusion of carbon dioxide and oxygen is approximately 10, times slower in water than it is in air. When soils become flooded, they quickly lose oxygen from low-concentration hypoxic to an anoxic environment where anaerobic bacteria thrive among the roots. Water also influences the spectral properties of light that becomes more diffuse as it is reflected off the water surface and submerged particles.

For example, the roots and stems develop large cellular air spaces to allow for the efficient transportation gases for example, CO 2 and O 2 used in respiration and photosynthesis. In drained soil, microorganisms use oxygen during respiration.

In aquatic environments, anaerobic soil microorganisms use nitrate, manganic ions, ferric ions, sulfate, carbon dioxide and some organic compounds. The activity of soil microorganisms and the chemistry of the water reduces the oxidation-reduction potentials of the water.

Carbon dioxide, for example, is reduced to methane CH 4 by methanogenic bacteria. Salt water also requires special physiological adaptations to deal with water loss.

Salt water plants or halophytes are able to osmo-regulate their internal salt NaCl concentrations or develop special organs for shedding salt away. Their gills form electrochemical gradients that mediate salt excrusion in salt water and uptake in fresh water. The shape and energy of the land is affected to a large degree by gravitational forces.

On a larger scale, the distribution of gravitational forces on the earth are uneven and influence the shape and movement of tectonic plates as well as having an influence on geomorphic processes such as orogeny and erosion. These forces govern many of the geophysical properties and distributions of ecological biomes across the Earth. On a organism scale, gravitational forces provide directional cues for plant and fungal growth gravitropism , orientation cues for animal migrations, and influence the biomechanics and size of animals.

Climatic and osmotic pressure places physiological constraints on organisms, such as flight and respiration at high altitudes, or diving to deep ocean depths. These constraints influence vertical limits of ecosystems in the biosphere as organisms are physiologically sensitive and adapted to atmospheric and osmotic water pressure differences. Mammals, such as whales, dolphins and seals are adapted to deal with changes in sound due to water pressure differences.

Turbulent forces in air and water have significant effects on the environment and ecosystem distribution, form and dynamics.

On a planetary scale, ecosystems are affected by circulation patterns in the global trade winds. Wind power and the turbulent forces it creates can influence heat, nutrient, and biochemical profiles of ecosystems. The westerlies, for example, come into contact with the coastal and interior mountains of western North America to produce a rain shadow on the leeward side of the mountain.

The air expands and moisture condenses as the winds move up in elevation which can cause precipitation; this is called orographic lift. This environmental process produces spatial divisions in biodiversity, as species adapted to wetter conditions are range-restricted to the coastal mountain valleys and unable to migrate across the xeric ecosystems of the Columbia Basin to intermix with sister lineages that are segregated to the interior mountain systems.

Plants convert carbon dioxide into biomass and emit oxygen into the atmosphere. Fire is a significant ecological parameter that raises many issues pertaining to its control and suppression in management. Fire creates environmental mosaics and a patchiness to ecosystem age and canopy structure. Native North Americans were among the first to influence fire regimes by controlling their spread near their homes or by lighting fires to stimulate the production of herbaceous foods and basketry materials.

Plants, for example, are equipped with a variety of adaptations to deal with forest fires. Some species e. This environmental trigger for seedlings is called serotiny.

Ecologists study and measure nutrient budgets to understand how these materials are regulated and flow through the environment. There are six major elements, including H hydrogen , C carbon , N nitrogen , O oxygen , S sulfur , and P phosphorus that form the constitution of all biological macromolecules and feed into the Earth's geochemical processes.

From the smallest scale of biology the combined effect of billions upon billions of ecological processes amplify and ultimately regulate the biogeochemical cycles of the Earth. Understanding the relations and cycles mediated between these elements and their ecological pathways has significant bearing toward understanding global biogeochemistry. The ecology of global carbon budgets gives one example of the linkage between biodiversity and biogeochemistry.

For starters, the Earth's oceans are estimated to hold 40, gigatonnes Gt carbon, vegetation and soil is estimated to hold Gt carbon, and fossil fuel emissions are estimated to emit an annual flux of 6. For example, through the early-mid Eocene volcanic outgassing, the oxidation of methane stored in wetlands, and seafloor gases increased atmospheric CO 2 concentrations to levels as high as ppm.

This new photosynthetic pathway evolved in response to the drop in atmospheric CO 2 concentrations below ppm. Loss in the abundance and distribution of biodiversity causes global carbon cycle feedbacks that are expected to increase rates of global warming in the next century. Hence, there is a relationship between global warming, decomposition and respiration in soils and wetlands producing significant climate feedbacks and altered global biogeochemical cycles.

Unlike many of the scientific disciplines, ecology has a complex and winding origin due in large part to its interdisciplinary nature.

Such examinations, conducted by important natural historians including James Hutton and Jean-Baptiste Lamarck , contributed to the development of ecology. By ecology we mean the body of knowledge concerning the economy of nature-the investigation of the total relations of the animal both to its inorganic and its organic environment; including, above all, its friendly and inimical relations with those animals and plants with which it comes directly or indirectly into contact-in a word, ecology is the study of all those complex interrelations referred to by Darwin as the conditions of the struggle of existence.

Opinions differ on who was the founder of modern ecological theory. Haeckel, who admired Darwin's work, defined ecology in reference to the economy of nature which has led some to question if ecology is synonymous with Linnaeus' concepts for the economy of nature. The modern synthesis of ecology is a young science, which first attracted substantial formal attention at the end of the 19th century around the same time as evolutionary studies and become even more popular during the s environmental movement.

For example, the concept on the balance or regulation of nature can be traced back to Herodotos died c. One of Aristotle's students, Theophrastus, made astute ecological observations about plants and posited a philosophical stance about the autonomous relations between plants and their environment that is more in line with modern ecological thought. Both Aristotle and Theophrastus made extensive observations on plant and animal migrations, biogeography, physiology, and their habits in what might be considered an analog of the modern ecological niche.

From Aristotle to Darwin the natural world was predominantly considered static and unchanged since its original creation. Prior to The Origin of Species there was little appreciation or understanding of the dynamic and reciprocal relations between organisms, their adaptations and their modifications to the environment.

This scientific paradigm changed the way that researchers approached the ecological sciences. Nowhere can one see more clearly illustrated what may be called the sensibility of such an organic complex,--expressed by the fact that whatever affects any species belonging to it, must speedily have its influence of some sort upon the whole assemblage.

He will thus be made to see the impossibility of studying any form completely, out of relation to the other forms,--the necessity for taking a comprehensive survey of the whole as a condition to a satisfactory understanding of any part.

The first American ecology book was published in by Frederic Clements. This publication launched a debate between ecological holism and individualism that lasted until the s. The Clements superorganism concept proposed that ecosystems progress through regular and determined stages of seral development that are analogous to developmental stages of an organism whose parts function to maintain the integrity of the whole.

The Clementsian paradigm was challenged by Henry Gleason. This perceptual shift placed the focus back onto the life histories of individual organisms and how this relates to the development of community associations. The Clementsian superorganism concept has not been completely rejected, but it was an overextended application of holism, [ ] which remains a significant theme in contemporary ecological studies.

Smuts was inspired by Clement's superorganism theory when he developed and published on the unifying concept of holism, which runs in stark contrast to his racial views as the father of apartheid. Fortunately, researchers have used ecological studies to advise on the effects land-conversion has on native species. Mangroves play a number of ecological roles from fixing sediments to acting as nursery site for young fish. Mangrove forests are also a source of food, medicine and firewood for local populations.

Support our mission and help develop the next generation of ecologists by donating to the British Ecological Society. We use cookies to make our website work properly and get anonymous information about how the site is used. Diversity and the BES What is ecology? It can only lay its eggs on lupine plants. Researchers studying ecology at the organismal level are interested in the adaptations that enable individuals to live in specific habitats.

These adaptations can be morphological pertaining to the study of form or structure , physiological, and behavioral. For instance, the Karner blue butterfly Lycaeides melissa samuelis is considered a specialist because the females preferentially oviposit that is, lay eggs on wild lupine. This preferential adaptation means that the Karner blue butterfly is highly dependent on the presence of wild lupine plants for its continued survival. Wild lupine : The wild lupine Lupinus perennis is the host plant for the Karner blue butterfly.

After hatching, the larval caterpillars emerge to spend four to six weeks feeding solely on wild lupine. The caterpillars pupate undergo metamorphosis , emerging as butterflies after about four weeks.

The adult butterflies feed on the nectar of flowers of wild lupine and other plant species. A population is a group of interbreeding organisms that are members of the same species living in the same area at the same time.

Organisms that are all members of the same species, a population, are called conspecifics. A population is identified, in part, by where it lives; its area of population may have natural or artificial boundaries. Natural boundaries might be rivers, mountains, or deserts, while examples of artificial boundaries include mowed grass or manmade structures such as roads. The study of population ecology focuses on the number of individuals in an area and how and why population size changes over time.

Population ecologists are particularly interested in counting the Karner blue butterfly, for example, because it is classified as federally endangered. However, the distribution and density of this species is highly influenced by the distribution and abundance of wild lupine.

Researchers might ask questions about the factors leading to the decline of wild lupine and how these affect Karner blue butterflies. For example, ecologists know that wild lupine thrives in open areas where trees and shrubs are largely absent.

In natural settings, intermittent wildfires regularly remove trees and shrubs, helping to maintain the open areas that wild lupine requires. Mathematical models can be used to understand how wildfire suppression by humans has led to the decline of this important plant for the Karner blue butterfly.

Community ecology studies interactions between different species; abiotic and biotic factors affect these on an ecosystem level. Years of ecological research have helped rice farmers adopt cropping strategies that simultaneously promote rice production and expand habitat for waterfowl.

The Environment Shapes Organisms. Figure 4: Gibbon demonstrating the use of flexible forelimbs for swinging in trees. Organisms Shape the Environment. References and Recommended Reading Beerling, D.

Burger, W. Flowers: How They Changed the World. Amherst, NY: Prometheus Books, Cowen, R. History of Life. Gaston, K. Global patterns in biodiversity. May, R. How many species are there on Earth? Sea Otters. Article History Close. Share Cancel. Revoke Cancel. Keywords Keywords for this Article. Save Cancel. Flag Inappropriate The Content is: Objectionable. Flag Content Cancel. Email your Friend. Submit Cancel. This content is currently under construction. Explore This Subject.

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