Homogeneity and heterogeneity#habitat heterogeneity

The words homogeneous and heterogeneous come from Medieval Latin homogeneus and heterogeneus, from Ancient Greek ὁμογενής (homogenēs) and ἑτερογενής (heterogenēs), from ὁμός (homos, "same") and ἕτερος (heteros, "other, another, different") respectively, followed by γένος (genos, "kind"); -ous is an adjectival suffix.

[https://web.archive.org/web/20120717050711/http://oxforddictionaries.com/definition/english/heterogeneous Heterogeneous: Definition in the Oxford English Dictionary]

Alternate spellings omitting the last -e- (and the associated pronunciations) are common, but mistaken:

[https://dictionary.cambridge.org/dictionary/english/homogeneous Cambridge Dictionary: homogeneous]

homogenous is strictly a biological/pathological term which has largely been replaced by homologous. But use of homogenous to mean homogeneous has seen a rise since 2000, enough for it to now be considered an "established variant".

[https://web.archive.org/web/20121003000741/http://oxforddictionaries.com/definition/english/homogeneous Homogeneous: Definition in the Oxford England Dictionary]

Similarly, heterogenous is a spelling traditionally reserved to biology and pathology, referring to the property of an object in the body having its origin outside the body.

[http://grammarist.com/usage/heterogeneous-heterogenous/ Heterogeneous vs. heterogenous] - Grammarist)

The concepts are the same to every level of complexity. From atoms to galaxies, plants, animals, humans, and other living organisms all share both a common or unique set of complexities.

Hence, an element may be homogeneous on a larger scale, compared to being heterogeneous on a smaller scale. This is known as an effective medium approximation.

{{Cite book

| last = Guéguen

| first =Yves

|author2=Palciauskas, Victor

| title =Introduction to the physics of rocks

| publisher =Princeton University Press

| date =May 1994

| pages = 53–72 (Chapter 3)

|url=https://books.google.com/books?id=fCP5qyRyX-oC&q=heterogeneous+physics&pg=PA53

| isbn =978-0-691-03452-2}}Google Books preview download available{{Cite journal| last1 = Shadrivov| first1 =Ilya V.| title =Nonlinear magnetic metamaterials|journal =Optics Express| volume =16| format =Introduction section. Free PDF download |pages =20266–71| date =2008-11-24|url=http://assets0.pubget.com/pdf/19065165.pdf

|doi =10.1364/OE.16.020266| access-date =2009-11-26| pmid = 19065165| last2 = Kozyrev| first2 = AB| last3 = Van Der Weide| first3 = DW| last4 = Kivshar| first4 = YS| issue = 25|bibcode = 2008OExpr..1620266S | hdl =10440/410| doi-access =free}}{{dead link|date=July 2016}}

Various disciplines understand heterogeneity, or being heterogeneous, in different ways.

{{cite web

|title=Webster's Revised Unabridged Dictionary (1913 + 1828)

|work=Heterogeneous

|publisher=The ARTFL Project, University of Chicago

|date=September 2010

|url=http://machaut.uchicago.edu/?action=search&word=heterogeneous&resource=Webster%27s&quicksearch=on

|format=Part of this paragraph is public domain material copyright 1828 and 1913

|access-date=2010-09-10

|url-status=dead

|archive-url=https://web.archive.org/web/20110728124031/http://machaut.uchicago.edu/?action=search&word=heterogeneous&resource=Webster%27s&quicksearch=on

|archive-date=2011-07-28

}}

{{expand section|date=January 2024}}

Environmental heterogeneity is a hypernym for different environmental factors that contribute to the diversity of species, like climate, topography, and land cover.{{cite journal |last1=Wan |first1=Ji-Zhong |last2=Wang |first2=Chun-Jing |last3=Marquet |first3=Pablo A |title=Environmental heterogeneity as a driver of terrestrial biodiversity on a global scale |journal=Progress in Physical Geography: Earth and Environment |date=December 2023 |volume=47 |issue=6 |pages=912–930 |doi=10.1177/03091333231189045 |s2cid=260849226 |url=https://journals.sagepub.com/doi/abs/10.1177/03091333231189045 |language=en |issn=0309-1333|url-access=subscription }} Biodiversity is correlated with geodiversity on a global scale. Heterogeneity in geodiversity features and environmental variables are indicators of environmental heterogeneity. They drive biodiversity at local and regional scales.

Scientific literature in ecology contains a big number of different terms for environmental heterogeneity, often undefined or conflicting in their meaning.{{cite journal |last1=Stein |first1=Anke |last2=Kreft |first2=Holger |title=Terminology and quantification of environmental heterogeneity in species-richness research |journal=Biological Reviews |date=August 2015 |volume=90 |issue=3 |pages=815–836 |doi=10.1111/brv.12135 |pmid=25099766 |s2cid=593580 |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/brv.12135 |language=en |issn=1464-7931|url-access=subscription }} {{vanchor|Habitat diversity}} and {{vanchor|habitat heterogeneity}} are a synonyms of environmental heterogeneity.

{{Main|Homogeneous and heterogeneous mixtures}}

In chemistry, a heterogeneous mixture consists of either or both of 1) multiple states of matter or 2) hydrophilic and hydrophobic substances in one mixture; an example of the latter would be a mixture of water, octane, and silicone grease. Heterogeneous solids, liquids, and gases may be made homogeneous by melting, stirring, or by allowing time to pass for diffusion to distribute the molecules evenly. For example, adding dye to water will create a heterogeneous solution at first, but will become homogeneous over time. Entropy allows for heterogeneous substances to become homogeneous over time.{{Cite web |title=Lessons |url=https://cecs.wright.edu/~gdong/mining03/tuto1/lesson_6.html#:~:text=Entropy%20measures%20the%20homogeneity%20(purity,of%20examples%20has%20more%20information. |access-date=2024-03-09 |website=cecs.wright.edu}}

A heterogeneous mixture is a mixture of two or more compounds. Examples are: mixtures of sand and water or sand and iron filings, a conglomerate rock, water and oil, a salad, trail mix, and concrete (not cement).{{cite book|last=Gamow|first=George|title=One Two Three... Infinity|date=April 1967|publisher=Bantam|edition=Bantam Science and Mathematics, 5th printing|author-link=George Gamow|page=117|type=Mass market paperback|chapter=Chapter VI, "Descending Staircase"|quote=[Clam chowder] represents a nice example of what is known as a heterogeneous material.}} A mixture can be determined to be homogeneous when everything is settled and equal, and the liquid, gas, the object is one color or the same form. Various models have been proposed to model the concentrations in different phases. The phenomena to be considered are mass rates and reaction.{{cn|date=July 2022}}

Homogeneous reactions are chemical reactions in which the reactants and products are in the same phase, while heterogeneous reactions have reactants in two or more phases. Reactions that take place on the surface of a catalyst of a different phase are also heterogeneous. A reaction between two gases or two miscible liquids is homogeneous. A reaction between a gas and a liquid, a gas and a solid or a liquid and a solid is heterogeneous.{{Citation needed|date=September 2010}}

Earth is a heterogeneous substance in many aspects; for instance, rocks (geology) are inherently heterogeneous, usually occurring at the micro-scale and mini-scale.

{{Main|Homogeneity (linguistics)}}

In formal semantics, homogeneity is the phenomenon in which plural expressions imply "all" when asserted but "none" when negated. For example, the English sentence "Robin read the books" means that Robin read all the books, while "Robin didn't read the books" means that she read none of them. Neither sentence can be asserted if Robin read exactly half of the books. This is a puzzle because the negative sentence does not appear to be the classical negation of the sentence. A variety of explanations have been proposed including that natural language operates on a trivalent logic.{{cite journal|last1=Križ|first1=Manuel|year=2019|title=Homogeneity effects in natural language semantics|journal=Language and Linguistics Compass|volume=13|issue=11|pages=e12350 |doi=10.1111/lnc3.12350|pmid=32699550 |pmc=7363159}}

{{see also|Heterogeneous network}}With information technology, heterogeneous computing occurs in a network comprising different types of computers, potentially with vastly differing memory sizes, processing power and even basic underlying architecture.{{Citation needed|date=September 2010}}

{{further|Homogeneity (disambiguation)#In mathematics}}

In algebra, homogeneous polynomials have the same number of factors of a given kind.

In the study of binary relations, a homogeneous relation R is on a single set (R ⊆ X × X) while a heterogeneous relation concerns possibly distinct sets (R ⊆ X × Y,  X = Y or X ≠ Y).{{cite book|last1=Schmidt|first1=Gunther|last2=Ströhlein|first2=Thomas|title=Relations and Graphs: Discrete Mathematics for Computer Scientists|date=2012|publisher=Springer Science & Business Media|isbn=978-3-642-77968-8|author-link1=Gunther Schmidt}}

In statistical meta-analysis, study heterogeneity is when multiple studies on an effect are measuring somewhat different effects due to differences in subject population, intervention, choice of analysis, experimental design, etc.; this can cause problems in attempts to summarize the meaning of the studies.

{{See also|Heterogeneous condition}}

In medicine and genetics, a genetic or allelic heterogeneous condition is one where the same disease or condition can be caused, or contributed to, by several factors, or in genetic terms, by varying or different genes or alleles.

In cancer research, cancer cell heterogeneity is thought to be one of the underlying reasons that make treatment of cancer difficult.{{cite journal|last=Bhatia|first=Sangeeta|author2=John V Frangioni |author3=Robert M Hoffman |author4=A John Iafrate |author5=Kornelia Polyak |title=The challenges posed by cancer heterogeneity|journal=Nature Biotechnology|date=10 July 2012|volume=30|issue=7|pages=604–610|doi=10.1038/nbt.2294|pmid=22781679|s2cid=15083285}}

{{main|Homogeneity (physics)}}

In physics, "heterogeneous" is understood to mean "having physical properties that vary within the medium".

In sociology, "heterogeneous" may refer to a society or group that includes individuals of differing ethnicities, cultural backgrounds, sexes, or ages. Diverse is the more common synonym in the context.[https://books.google.com/books?id=ibzZZxWC_vEC Dictionary of Sociology]. Routledge; 12 November 2012. {{ISBN|978-1-136-59845-6}}.

In landscape ecology, heterogeneity refers to the different elements of a system. {{Cite book |last=Turner |first=Monica G. |url=https://link.springer.com/10.1007/978-1-4939-2794-4 |title=Landscape Ecology in Theory and Practice: Pattern and Process |last2=Gardner |first2=Robert H. |date=2015 |publisher=Springer |isbn=978-1-4939-2793-7 |location=New York, NY |language=en |doi=10.1007/978-1-4939-2794-4}} Heterogeneous systems support higher biodiversity and is a target for many landscape restoration efforts. {{Cite journal |last=Cardoso |first=Fernanda C. G. |last2=Capellesso |first2=Elivane S. |last3=de Britez |first3=Ricardo Miranda |last4=Inague |first4=Gabriel |last5=Marques |first5=Marcia C. M. |date=September 2022 |title=Landscape conservation as a strategy for recovering biodiversity: Lessons from a long‐term program of pasture restoration in the southern Atlantic Forest |url=https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.14240 |journal=Journal of Applied Ecology |language=en |volume=59 |issue=9 |pages=2309–2321 |doi=10.1111/1365-2664.14240 |issn=0021-8901|url-access=subscription }}

• Complete spatial randomness
• Heterologous
• Epidemiology
• Spatial analysis
• Statistical hypothesis testing
• Homogeneity blockmodeling

{{Reflist|30em}}

{{Wiktionary|homogeneity|heterogeneity|homogeneous|heterogeneous}}

{{Wikiquote|Homogeneity}}

• The following cited pages in this book cover the meaning of "homogeneity" across disciplines: {{Cite book |last=Morris |first=Christopher G. |year=1992 |title=Academic Press Dictionary of Science and Technology |url=https://archive.org/details/academicpressdic00morr |url-access=registration |publisher = Gulf Professional Publishing |pages=[https://archive.org/details/academicpressdic00morr/page/n1082 1039], 1040 |isbn=0-12-200400-0 |quote=Homogeneity in physics.}}

{{DEFAULTSORT:Homogeneous And Heterogeneous Reactions}}

Category:Chemical reactions

Category:Scientific terminology

de:Heterogenität

eu:Homogeneo eta heterogeneo