Niche construction

Niche construction is the process by which an organism alters its own (or another species') local environment. These alterations can be a physical change to the organism’s environment or encompass when an organism actively moves from one habitat to another to experience a different environment. Examples of niche construction include the building of nests and burrows by animals, and the creation of shade, influencing of wind speed, and alternation of nutrient cycling by plants. Although these alterations are often beneficial to the constructor they are not always (for example, when organisms dump detritus they can degrade their own environments).

Beaver dam in Tierra del Fuego
Beavers hold a very specific biological niche in the ecosystem: constructing dams across river systems.

Evolution

For niche construction to affect evolution it must satisfy three criteria: 1) the organism must significantly modify environmental conditions, 2) these modifications must influence one or more selection pressures on a recipient organism, and 3) there must be an evolutionary response in at least one recipient population caused by the environmental modification.[1][2] The first two criteria alone provide evidence of niche construction.

Recently, some biologists have argued that niche construction is an evolutionary process that works in conjunction with natural selection.[1] Evolution entails networks of feedbacks in which previously selected organisms drive environmental changes, and organism-modified environments subsequently select for changes in organisms.[1][3][4] The complementary match between an organism and its environment results from the two processes of natural selection and niche construction. The effect of niche construction is especially pronounced in situations where environmental alterations persist for several generations, introducing the evolutionary role of ecological inheritance. This theory emphasizes that organisms inherit two legacies from their ancestors: genes and a modified environment. A niche constructing organism may or may not be considered an ecosystem engineer. Ecosystem engineering is a related but non-evolutionary concept referring to structural changes brought about in the environment by organisms.[5]

Examples

Leafcutter ants transporting leaves
Leafcutter ants fill a vital niche in the rainforest ecosystem

The following are some examples of niche construction:

  • Earthworms physically and chemically modify the soil in which they live. Only by changing the soil can these primarily aquatic organisms live on land.[6] Earthworm soil processing benefits plant species and other biota present in the soil, as originally pointed out by Darwin in his book The Formation of Vegetable Mould through the Action of Worms.
  • Lemon ants (Myrmelachista schumanni) employ a specialized method of suppression that regulates the growth of certain trees. They live in the trunks of Duroia hirsuta trees found in the Amazonian rain forest of Peru. Lemon ants use formic acid (a chemical fairly common among species of ants) as a herbicide. By eliminating trees unsuitable for lemon ant colonies, these ants produce distinctive habitats known as Devil's gardens.[7]
  • Beavers build dams and thereby create lakes that drastically shape and alter riparian ecosystems. These activities modify nutrient cycling and decomposition dynamics, influence the water and materials transported downstream, and ultimately influence plant and community composition and diversity.[8]
  • Benthic diatoms living in estuarine sediments in the Bay of Fundy, Canada, secrete carbohydrate exudates that bind the sand and stabilize the environment. This changes the physical state of the sand which allows other organisms (such as the amphipod Corophium volutator) to colonize the area.[9]
  • Chaparrals and pines increase the frequency of forest fire through the dispersal of needles, cones, seeds and oils, essentially littering the forest floor. The benefit of this activity is facilitated by an adaptation for fire resistance which benefits them relative to their competitors.[10]
  • Saccharomyces cerevisiae yeast creates a novel environment out of fermenting fruit. This fermentation process in turn attracts fruit flies that it is closely associated with and utilizes for transportation.[11]
  • Cyanobacteria provide an example on a planetary scale through the production of oxygen as a waste product of photosynthesis (see Great Oxygenation Event). This dramatically changed the composition of the Earth’s atmosphere and oceans, with vast macroevolutionary and ecological consequences.[12]

Consequences

Reed warbler cuckoo
A Reed Warbler feeding its large, infant intruder.

As creatures construct new niches, they can have a significant effect on the world around them.[1]

  • An important consequence of niche construction is that it can affect the natural selection experienced by the species doing the constructing. The common cuckoo illustrates such a consequence. It parasitizes other birds by laying its eggs in their nests. This had led to several adaptations among the cuckoos, including a short incubation time for their eggs. The eggs need to hatch first so that the chick can push the host's eggs out of the nest, ensuring it has no competition for the parents' attention. Another adaptation it has acquired is that the chick mimics the calls of multiple young chicks, so that the parents are bringing in food not just for one offspring, but a whole brood.[1][13]
  • Niche construction can also generate co-evolutionary interactions, as illustrated by the above earthworm, beaver and yeast examples.
  • The development of many organisms, and the recurrence of traits across generations, has been found to depend critically on the construction of developmental environments such as nests by ancestral organisms. Ecological inheritance refers to the inherited resources and conditions, and associated modified selection pressures, that ancestral organisms bequeath to their descendants as a direct result of their niche construction.
  • Niche construction has important implications for understanding, managing, and conserving ecosystems.[9]

History

Niche construction theory (NCT) has been anticipated by diverse people in the past, including by the physicist Erwin Schrödinger in his What Is Life? and Mind and Matter essays (1944). An early advocate of the niche construction perspective in biology was the developmental biologist, Conrad Waddington. He drew his attention to the many ways in which animals modify their selective environments throughout their lives, by choosing and changing their environmental conditions, a phenomenon that he termed "the exploitive system".[14]

The niche construction perspective was subsequently brought to prominence through the writings of Harvard evolutionary biologist, Richard Lewontin. In the 1970s and 1980s Lewontin wrote a series of articles on adaptation, in which he pointed out that organisms do not passively adapt through selection to pre-existing conditions, but actively construct important components of their niches.[4]

Oxford biologist John Odling-Smee (1988) was the first person to coin the term 'niche construction', and the first to make the argument that ‘niche construction’ and ‘ecological inheritance’ should be recognized as evolutionary processes.[15] Over the next decade research into niche construction increased rapidly, with a rush of experimental and theoretical studies across a broad range of fields.

Modeling niche construction

Niche construction in evolutionary time
Niche Construction in Evolutionary Time. The organism both changes its environment and adapts to it.[16]

Mathematical evolutionary theory explores both the evolution of niche construction, and its evolutionary and ecological consequences. These analyses suggest that niche construction is of considerable importance. For instance, niche construction can:

  • fix genes or phenotypes that would otherwise be deleterious, create or eliminate equilibria, and affect evolutionary rates;[17][18][19]
  • cause evolutionary time lags, generate momentum, inertia, autocatalytic effects, catastrophic responses to selection, and cyclical dynamics;[17][19]
  • drive niche-constructing traits to fixation by creating statistical associations with recipient traits;[18]
  • facilitate the evolution of cooperation;[20][21]
  • regulate environmental states, allowing persistence in otherwise inhospitable conditions, facilitating range expansion and affecting carrying capacities;[22][23]
  • drive coevolutionary events, exacerbate and ameliorate competition, affect the likelihood of coexistence and produce macroevolutionary trends.[23]

Humans

Niche construction theory has had a particular impact in the human sciences, including biological anthropology,[24] archaeology,[25] and psychology.[26] Niche construction is now recognized to have played important roles in human evolution,[24][27] including the evolution of cognitive capabilities.[28] Its impact is probably because it is immediately apparent that humans possess an unusually potent capability to regulate, construct and destroy their environments, and that this is generating some pressing current problems (e.g. climate change, deforestation, urbanization). However, human scientists have been attracted to the niche construction perspective because it recognizes human activities as a directing process, rather than merely the consequence of natural selection.[1][25] Cultural niche construction can also feed back to affect other cultural processes, without affecting genetics.

Niche construction theory emphasizes how acquired characters play an evolutionary role, through transforming selective environments. This is particularly relevant to human evolution, where our species appears to have engaged in extensive environmental modification through cultural practices.[29] Such cultural practices are typically not themselves biological adaptations (rather, they are the adaptive product of those much more general adaptations, such as the ability to learn, particularly from others, to teach, to use language, and so forth, that underlie human culture).

Mathematical models have established that cultural niche construction can modify natural selection on human genes and drive evolutionary events. This interaction is known as gene-culture coevolution. There is now little doubt that human cultural niche construction has co-directed human evolution.[29] Humans have modified selection, for instance, by dispersing into new environments with different climatic regimes, devising agricultural practices or domesticating livestock. A well-researched example is the finding that dairy farming created the selection pressure that led to the spread of alleles for adult lactase persistence.[30] Analyses of the human genome have identified many hundreds of genes subject to recent selection, and human cultural activities are thought to be a major source of selection in many cases. The lactose persistence example may be representative of a very general pattern of gene-culture coevolution.

Niche construction is also now central to several accounts of how language evolved. For instance, Derek Bickerton describes how our ancestors constructed scavenging niches that required them to communicate in order to recruit sufficient individuals to drive off predators away from megafauna corpses.[28] He maintains that our use of language, in turn, created a new niche in which sophisticated cognition was beneficial.

Current status

While the fact that niche construction occurs is non-contentious, and its study goes back to Darwin's classic books on earthworms and corals, the evolutionary consequences of niche construction have not always been fully appreciated. Researchers differ over to what extent niche construction requires changes in understanding of the evolutionary process. Many advocates of the niche-construction perspective align themselves with other progressive elements in seeking an extended evolutionary synthesis,[31][32] a stance that other prominent evolutionary biologists reject.[33] Laubichler and Renn[32] argue that niche construction theory offers the prospect of a broader synthesis of evolutionary phenomena through "the notion of expanded and multiple inheritance systems (from genomic to ecological, social and cultural)."[32]

Niche construction theory (NCT) remains controversial, particularly amongst orthodox evolutionary biologists.[34][35] In particular, the claim that niche construction is an evolutionary process has excited controversy. A collaboration between some critics of the niche-construction perspective and one of its advocates attempted to pinpoint their differences.[35] They wrote:

"NCT argues that niche construction is a distinct evolutionary process, potentially of equal importance to natural selection. The skeptics dispute this. For them, evolutionary processes are processes that change gene frequencies, of which they identify four (natural selection, genetic drift, mutation, migration [ie. gene flow])... They do not see how niche construction either generates or sorts genetic variation independently of these other processes, or how it changes gene frequencies in any other way. In contrast, NCT adopts a broader notion of an evolutionary process, one that it shares with some other evolutionary biologists. Although the advocate agrees that there is a useful distinction to be made between processes that modify gene frequencies directly, and factors that play different roles in evolution... The skeptics probably represent the majority position: evolutionary processes are those that change gene frequencies. Advocates of NCT, in contrast, are part of a sizable minority of evolutionary biologists that conceive of evolutionary processes more broadly, as anything that systematically biases the direction or rate of evolution, a criterion that they (but not the skeptics) feel niche construction meets."[35]

The authors conclude that their disagreements reflect a wider dispute within evolutionary theory over whether the modern synthesis is in need of reformulation, as well as different usages of some key terms (e.g., evolutionary process).

Further controversy surrounds the application of niche construction theory to the origins of agriculture within archaeology. In a 2015 review, archaeologist Bruce Smith concluded: "Explanations [for domestication of plants and animals] based on diet breadth modeling are found to have a number of conceptual, theoretical, and methodological flaws; approaches based on niche construction theory are far better supported by the available evidence in the two regions considered [eastern North America and the Neotropics]".[36] However, other researchers see no conflict between niche construction theory and the application of behavioral ecology methods in archaeology.[37][38]

A critical review by Manan Gupta and colleagues was published in 2017 which led to a dispute amongst critics and proponents.[39][40][41]

See also

References

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  2. ^ Matthews, Blake; De Meester, Luc; Jones, Clive G; Ibelings, Bas W; Bouma, Tjeerd J; Nuutinen, Visa; De Koppel, Johan van; Odling-Smee, John (2014). "Under niche construction: An operational bridge between ecology, evolution, and ecosystem science" (PDF). Ecological Monographs. 84 (2): 245–63. doi:10.1890/13-0953.1. JSTOR 43187889.
  3. ^ Levins, Richard; Lewontin, Richard C. (1985). The Dialectical Biologist. Cambridge, MA: Harvard University Press.
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  20. ^ Lehmann, Laurent (2008). "The Adaptive Dynamics of Niche Constructing Traits in Spatially Subdivided Populations: Evolving Posthumous Extended Phenotypes". Evolution. 62 (3): 549–66. doi:10.1111/j.1558-5646.2007.00291.x. PMID 17983464.
  21. ^ Van Dyken, J. David; Wade, Michael J (2012). "Origins of Altruism Diversity Ii: Runaway Coevolution of Altruistic Strategies Via 'Reciprocal Niche Construction'". Evolution. 66 (8): 2498–513. doi:10.1111/j.1558-5646.2012.01629.x. PMC 3408633. PMID 22834748.
  22. ^ Kylafis, G.; Loreau, M. (2008). "Ecological and evolutionary consequences of niche construction for its agent". Ecology Letters. 11 (10): 1072–1081. doi:10.1111/j.1461-0248.2008.01220.x. PMID 18727670.
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  29. ^ a b Laland, KN.; Odling-Smee, FJ.; Myles, S. (2010). "How culture shaped the human genome: Bringing genetics and the human sciences together". Nature Reviews Genetics. 11 (2): 137–148. doi:10.1038/nrg2734. PMID 20084086.
  30. ^ Gerbault, P.; Liebert, A.; Itan, Y.; Powell, A.; Currat, M.; Burger, J.; Swallow, DS.; Thomas, MG. (2011). "Evolution of lactase persistence: an example of human niche construction". Phil Trans R Soc B. 366 (1566): 863–877. doi:10.1098/rstb.2010.0268. PMC 3048992. PMID 21320900.
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  32. ^ a b c Laubichler, Manfred D.; Renn, Jürgen (2015). "Extended evolution: A Conceptual Framework for Integrating Regulatory Networks and Niche Construction". J Exp Zool (Mol Dev Evol). 324 (7): 565–577. doi:10.1002/jez.b.22631. PMC 4744698. PMID 26097188.
  33. ^ Laland, Kevin; Uller, Tobias; Feldman, Marc; Sterelny, Kim; Müller, Gerd B; Moczek, Armin; Jablonka, Eva; Odling-Smee, John; Wray, Gregory A; Hoekstra, Hopi E; Futuyma, Douglas J; Lenski, Richard E; MacKay, Trudy F. C; Schluter, Dolph; Strassmann, Joan E (2014). "Does evolutionary theory need a rethink?". Nature. 514 (7521): 161–4. Bibcode:2014Natur.514..161L. doi:10.1038/514161a. PMID 25297418.
  34. ^ Pocheville, Arnaud (2010). "What Niche Construction is (not)". La Niche Ecologique: Concepts, Modèles, Applications (PhD Thesis). Paris: Ecole Normale Supérieure. pp. 39–124.
  35. ^ a b c Scott-Phillips, Thomas C; Laland, Kevin N; Shuker, David M; Dickins, Thomas E; West, Stuart A (2014). "The Niche Construction Perspective: A Critical Appraisal". Evolution. 68 (5): 1231–43. doi:10.1111/evo.12332. PMC 4261998. PMID 24325256.
  36. ^ Smith, Bruce (2015). "A Comparison of Niche Construction Theory and Diet Breadth Models as Explanatory Frameworks for the Initial Domestication of Plants and Animals". Journal of Archaeological Research. 23 (3): 215–262. doi:10.1007/s10814-015-9081-4.
  37. ^ Laland, Kevin N.; Brown, Gillian R. (2006). "Niche construction, human behavior, and the adaptive-lag hypothesis". Evolutionary Anthropology. 15 (3): 95–104. doi:10.1002/evan.20093.
  38. ^ Stiner, MC.; Kuhn, SL. (2016). "Are we missing the "sweet spot" between optimality theory and niche construction theory in archaeology?". J Anthropol Archaeol. 44: 177–184. doi:10.1016/j.jaa.2016.07.006.
  39. ^ Gupta, M., N. G. Prasad, S. Dey, A. Joshi, and T. N. C. Vidya. (2017). "Niche construction in evolutionary theory: the construction of an academic niche?" Journal of Genetics 96 (3): 491–504.
  40. ^ Feldman, M. W; Odling-Smee, J; Laland, K. N. (2017). "Why Gupta et al.'s critique of niche construction theory is off target". Journal of Genetics 96 (3): 505-508.
  41. ^ Gupta, Manan; Prasad, N. G; Dey, Sutirth; Joshi, Amitabh; Vidya, T. N. C. (2017). "Feldman et al. do protest too much, we think". Journal of Genetics 96 (3): 509–511.

Further reading

External links

Affordance

Affordance is what the environment offers the individual. James J. Gibson, coined the term in his 1966 book, The Senses Considered as Perceptual Systems, and it occurs in many of his earlier essays (e.g.). However, his best-known definition is taken from his seminal 1979 book, The Ecological Approach to Visual Perception:The affordances of the environment are what it offers the animal, what it provides or furnishes, either for good or ill. The verb to afford is found in the dictionary, the noun affordance is not. I have made it up. I mean by it something that refers to both the environment and the animal in a way that no existing term does. It implies the complementarity of the animal and the environment.

The original definition in psychology includes all transactions that are possible between an individual and their environment. When the concept was applied to design, it started also referring to only those physical action possibilities of which one is aware.

The word is used in a variety of fields: perceptual psychology, cognitive psychology, environmental psychology, industrial design, human–computer interaction (HCI), interaction design, user-centered design, communication studies, instructional design, science, technology and society (STS), sports science and artificial intelligence.

Allele frequency

Allele frequency, or gene frequency, is the relative frequency of an allele (variant of a gene) at a particular locus in a population, expressed as a fraction or percentage. Specifically, it is the fraction of all chromosomes in the population that carry that allele. Microevolution is the change in allele frequencies that occurs over time within a population.

Given the following:

a particular locus on a chromosome and a given allele at that locus

a population of N individuals with ploidy n, i.e. an individual carries n copies of each chromosome in their somatic cells (e.g. two chromosomes in the cells of diploid species)

the allele exists in i chromosomes in the populationthen the allele frequency is the fraction of all the occurrences i of that allele and the total number of chromosome copies across the population, i/(nN).

The allele frequency is distinct from the genotype frequency, although they are related, and allele frequencies can be calculated from genotype frequencies.In population genetics, allele frequencies are used to describe the amount of variation at a particular locus or across multiple loci. When considering the ensemble of allele frequencies for a large number of distinct loci, their distribution is called the allele frequency spectrum.

Bacterivore

Bacterivores are free-living, generally heterotrophic organisms, exclusively microscopic, which obtain energy and nutrients primarily or entirely from the consumption of bacteria. Many species of amoeba are bacterivores, as well as other types of protozoans. Commonly, all species of bacteria will be prey, but spores of some species, such as Clostridium perfringens, will never be prey, because of their cellular attributes.

Copiotroph

A copiotroph is an organism found in environments rich in nutrients, particularly carbon. They are the opposite to oligotrophs, which survive in much lower carbon concentrations.

Copiotrophic organisms tend to grow in high organic substrate conditions. For example, copiotrophic organisms grow in Sewage lagoons. They grow in organic substrate conditions up to 100x higher than oligotrophs.

Decomposer

Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development. While the terms decomposer and detritivore are often interchangeably used, detritivores must ingest and digest dead matter via internal processes while decomposers can directly absorb nutrients through chemical and biological processes hence breaking down matter without ingesting it. Thus, invertebrates such as earthworms, woodlice, and sea cucumbers are technically detritivores, not decomposers, since they must ingest nutrients and are unable to absorb them externally.

Dominance (ecology)

Ecological dominance is the degree to which a taxon is more numerous than its competitors in an ecological community, or makes up more of the biomass.

Most ecological communities are defined by their dominant species.

In many examples of wet woodland in western Europe, the dominant tree is alder (Alnus glutinosa).

In temperate bogs, the dominant vegetation is usually species of Sphagnum moss.

Tidal swamps in the tropics are usually dominated by species of mangrove (Rhizophoraceae)

Some sea floor communities are dominated by brittle stars.

Exposed rocky shorelines are dominated by sessile organisms such as barnacles and limpets.

Ecological inheritance

Ecological inheritance is the passing on to descendants of inherited resources and conditions, and associated modified selection pressures, through niche construction. For instance, many organisms build, choose or provision nursery environments, such as nests, for their offspring. The recurrence of traits across life cycles results in part from parents constructing developmental conditions for their descendants. Richard Lewontin stresses how by modifying the availability of biotic and abiotic resources, niche-constructing organisms can cause organisms to coevolve with their environments.Ecological inheritance has significant implications for macroevolution. Ancestral species may modify environments through their niche construction that may have consequences for other species, sometimes millions of years later. For instance, cyanobacteria produced oxygen as a waste product of photosynthesis (see great oxygenation event), which dramatically changed the composition of the Earth’s atmosphere and oceans, with vast macroevolutionary consequences.

In recent years, many evolutionary biologists have sought to expand the concept of inheritance within evolutionary biology, and ecological inheritance is now commonly incorporated into these schemes. The evolutionary significance of ecological inheritance, however, remains disputed.

Ecological niche

In ecology, a niche (CanE, UK: or US: ) is the match of a species to a specific environmental condition. It describes how an organism or population responds to the distribution of resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (for example, limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another [and] the relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts".A Grinnellian niche is determined by the habitat in which a species lives and its accompanying behavioral adaptations. An Eltonian niche emphasizes that a species not only grows in and responds to an environment, it may also change the environment and its behavior as it grows. The Hutchinsonian niche uses mathematics and statistics to try to explain how species coexist within a given community.

The concept of ecological niche is central to ecological biogeography, which focuses on spatial patterns of ecological communities. "Species distributions and their dynamics over time result from properties of the species, environmental variation..., and interactions between the two—in particular the abilities of some species, especially our own, to modify their environments and alter the range dynamics of many other species." Alteration of an ecological niche by its inhabitants is the topic of niche construction.The majority of species exist in a standard ecological niche, sharing behaviors, adaptations, and functional traits similar to the other closely related species within the same broad taxonomic class, but there are exceptions. A premier example of a non-standard niche filling species is the flightless, ground-dwelling kiwi bird of New Zealand, which feeds on worms and other ground creatures, and lives its life in a mammal-like niche. Island biogeography can help explain island species and associated unfilled niches.

Ecology

Ecology (from Greek: οἶκος, "house", or "environment"; -λογία, "study of") is the branch of biology which studies the interactions among organisms and their environment. Objects of study include interactions of organisms that include biotic and abiotic components of their environment. Topics of interest include the biodiversity, distribution, biomass, and populations of organisms, as well as cooperation and competition within and between species. Ecosystems are dynamically interacting systems of organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and niche construction, regulate the flux of energy and matter through an environment. These processes are sustained by organisms with specific life history traits. Biodiversity means the varieties of species, genes, and ecosystems, enhances certain ecosystem services.

Ecology is not synonymous with environmentalism, natural history, or environmental science. It overlaps with the closely related sciences of evolutionary biology, genetics, and ethology. An important focus for ecologists is to improve the understanding of how biodiversity affects ecological function. Ecologists seek to explain:

Life processes, interactions, and adaptations

The movement of materials and energy through living communities

The successional development of ecosystems

The abundance and distribution of organisms and biodiversity in the context of the environment.Ecology has practical applications in conservation biology, wetland management, natural resource management (agroecology, agriculture, forestry, agroforestry, fisheries), city planning (urban ecology), community health, economics, basic and applied science, and human social interaction (human ecology). For example, the Circles of Sustainability approach treats ecology as more than the environment 'out there'. It is not treated as separate from humans. Organisms (including humans) and resources compose ecosystems which, in turn, maintain biophysical feedback mechanisms that moderate processes acting on living (biotic) and non-living (abiotic) components of the planet. Ecosystems sustain life-supporting functions and produce natural capital like biomass production (food, fuel, fiber, and medicine), the regulation of climate, global biogeochemical cycles, water filtration, soil formation, erosion control, flood protection, and many other natural features of scientific, historical, economic, or intrinsic value.

The word "ecology" ("Ökologie") was coined in 1866 by the German scientist Ernst Haeckel. Ecological thought is derivative of established currents in philosophy, particularly from ethics and politics. Ancient Greek philosophers such as Hippocrates and Aristotle laid the foundations of ecology in their studies on natural history. Modern ecology became a much more rigorous science in the late 19th century. Evolutionary concepts relating to adaptation and natural selection became the cornerstones of modern ecological theory.

Ecosystem engineer

An ecosystem engineer is any organism that creates, significantly modifies, maintains or destroys a habitat. These organisms can have a large impact on the species richness and landscape-level heterogeneity of an area. As a result, ecosystem engineers are important for maintaining the health and stability of the environment they are living in. Since all organisms impact the environment they live in in one way or another, it has been proposed that the term "ecosystem engineers" be used only for keystone species whose behavior very strongly affects other organisms.

Evolutionary psychology and culture

Evolutionary psychology has traditionally focused on individual-level behaviors, determined by species-typical psychological adaptations. Considerable work, though, has been done on how these adaptations shape and, ultimately govern, culture (Tooby and Cosmides, 1989). Tooby and Cosmides (1989) argued that the mind consists of many domain-specific psychological adaptations, some of which may constrain what cultural material is learned or taught. As opposed to a domain-general cultural acquisition program, where an individual passively receives culturally-transmitted material from the group, Tooby and Cosmides (1989), among others, argue that: "the psyche evolved to generate adaptive rather than repetitive behavior, and hence critically analyzes the behavior of those surrounding it in highly structured and patterned ways, to be used as a rich (but by no means the only) source of information out of which to construct a 'private culture' or individually tailored adaptive system; in consequence, this system may or may not mirror the behavior of others in any given respect." (Tooby and Cosmides 1989).

Extended evolutionary synthesis

The extended evolutionary synthesis consists of a set of theoretical concepts argued to be more comprehensive than the earlier modern synthesis of evolutionary biology that took place between 1918 and 1942. The extended evolutionary synthesis was called for in the 1950s by C. H. Waddington, argued for on the basis of punctuated equilibrium by Stephen Jay Gould and Niles Eldredge in the 1980s, and was reconceptualized in 2007 by Massimo Pigliucci and Gerd B. Müller.

The extended evolutionary synthesis revisits the relative importance of different factors at play, examining several assumptions of the earlier synthesis, and augmenting it with additional causative factors. It includes multilevel selection, transgenerational epigenetic inheritance, niche construction, evolvability, and several concepts from evolutionary developmental biology.Not all biologists have agreed on the need for, or the scope of, an extended synthesis. Many have collaborated on another synthesis in evolutionary developmental biology, which concentrates on developmental molecular genetics and evolution to understand how natural selection operated on developmental processes and deep homologies between organisms at the level of highly conserved genes.

Feeding frenzy

In ecology, a feeding frenzy occurs when predators are overwhelmed by the amount of prey available. For example, a large school of fish can cause nearby sharks, such as the lemon shark, to enter into a feeding frenzy. This can cause the sharks to go wild, biting anything that moves, including each other or anything else within biting range. Another functional explanation for feeding frenzy is competition amongst predators. This term is most often used when referring to sharks or piranhas. It has also been used as a term within journalism.

Karola Stotz

Karola Stotz (born 8 September 1963 in Neumünster, Schleswig-Holstein, Germany) is a German scholar of philosophy of biology, cognitive science, and philosophy of science. With Paul E. Griffiths, she pioneered the use of experimental philosophy methods in the field of philosophy of science.

Mesotrophic soil

Mesotrophic soils are soils with a moderate inherent fertility. An indicator of soil fertility is its base status, which is expressed as a ratio relating the major nutrient cations (calcium, magnesium, potassium and sodium) found there to the soil's clay percentage. This is commonly expressed in hundredths of a mole of cations per kilogram of clay, i.e. cmol (+) kg−1 clay.

Mycotroph

A mycotroph is a plant that gets all or part of its carbon, water, or nutrient supply through symbiotic association with fungi. The term can refer to plants that engage in either of two distinct symbioses with fungi:

Many mycotrophs have a mutualistic association with fungi in any of several forms of mycorrhiza. The majority of plant species are mycotrophic in this sense. Examples include Burmanniaceae.

Some mycotrophs are parasitic upon fungi in an association known as myco-heterotrophy.

Organotroph

An organotroph is an organism that obtains hydrogen or electrons from organic substrates. This term is used in microbiology to classify and describe organisms based on how they obtain electrons for their respiration processes. Some organotrophs such as animals and many bacteria, are also heterotrophs. Organotrophs can be either anaerobic or aerobic.

Antonym: Lithotroph, Adjective: Organotrophic.

Recruitment (biology)

In biology, especially marine biology, recruitment occurs when a juvenile organism joins a population, whether by birth or immigration, usually at a stage whereby the organisms are settled and able to be detected by an observer.There are two types of recruitment: closed and open.In the study of fisheries, recruitment is "the number of fish surviving to enter the fishery or to some life history stage such as settlement or maturity".

The Extended Phenotype

The Extended Phenotype is a 1982 book by Richard Dawkins, in which the author introduced a biological concept of the same name. The main idea is that phenotype should not be limited to biological processes such as protein biosynthesis or tissue growth, but extended to include all effects that a gene has on its environment, inside or outside the body of the individual organism.

Dawkins considers The Extended Phenotype to be a sequel to The Selfish Gene (1976) aimed at professional biologists, and as his principal contribution to evolutionary theory.

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Ecology: Modelling ecosystems: Other components
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