Ecology in the context of Unity in diversity

Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of life. Central to biology are five fundamental themes: the cell as the basic unit of life, genes and heredity as the basis of inheritance, evolution as the driver of biological diversity, energy transformation for sustaining life processes, and the maintenance of internal stability (homeostasis).

Biology examines life across multiple levels of organization, from molecules and cells to organisms, populations, and ecosystems. Subdisciplines include molecular biology, physiology, ecology, evolutionary biology, developmental biology, and systematics, among others. Each of these fields applies a range of methods to investigate biological phenomena, including observation, experimentation, and mathematical modeling. Modern biology is grounded in the theory of evolution by natural selection, first articulated by Charles Darwin, and in the molecular understanding of genes encoded in DNA. The discovery of the structure of DNA and advances in molecular genetics have transformed many areas of biology, leading to applications in medicine, agriculture, biotechnology, and environmental science.

Alfred North Whitehead OM FRS FBA (15 February 1861 – 30 December 1947) was an English mathematician and philosopher. He created the philosophical school known as process philosophy, which has been applied in a wide variety of disciplines, including ecology, theology, education, physics, biology, economics, and psychology.

In his early career Whitehead wrote primarily on mathematics, logic, and physics. He wrote the three-volume Principia Mathematica (1910–1913), with his former student Bertrand Russell. Principia Mathematica is considered one of the twentieth century's most important works in mathematical logic, and placed 23rd in a list of the top 100 English-language nonfiction books of the twentieth century by Modern Library.

A sustainable city, eco-city, or green city is a city designed with consideration for the social, economic, and environmental impact (commonly referred to as the triple bottom line), as well as a resilient habitat for existing populations. The UN Sustainable Development Goal 11 defines as one that is dedicated to achieving green, social, and economic sustainability, facilitating opportunities that prioritize inclusivity as well as maintaining a sustainable economic growth. Furthermore, the objective is to minimize the inputs of energy, water, and food, and to drastically reduce waste, as well as the outputs of heat, air pollution (including CO2, methane, and water pollution).

The UN Environment Programme calls out that most cities today are struggling with environmental degradation, traffic congestion, inadequate urban infrastructure, in addition to a lack of basic services, such as water supply, sanitation, and waste management. A sustainable city should promote economic growth and meet the basic needs of its inhabitants, while creating sustainable living conditions for all. Ideally, a sustainable city is one that creates an enduring way of life across the four domains of ecology, economics, politics, and culture. The European Investment Bank is assisting cities in the development of long-term strategies in fields including renewable transportation, energy efficiency, sustainable housing, education, and health care. The European Investment Bank has spent more than €150 billion in bettering cities over the last eight years.

Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Phytogeography is the branch of biogeography that studies the distribution of plants, Zoogeography is the branch that studies distribution of animals, while Mycogeography is the branch that studies distribution of fungi, such as mushrooms.

Knowledge of spatial variation in the numbers and types of organisms is as vital to us today as it was to our early human ancestors, as we adapt to heterogeneous but geographically predictable environments. Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, taxonomy, geology, physical geography, palaeontology, and climatology.

Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologically, where the term covers several slightly different but related regions.

In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them underpin biology as a whole. They affect a plethora of species, in all forms of environmental conditions, such as marine or terrestrial animals. Humans can make or change abiotic factors in a species' environment. For instance, fertilizers can affect a snail's habitat, or the greenhouse gases which humans utilize can change marine pH levels.

Abiotic components include physical conditions and non-living resources that affect living organisms in terms of growth, maintenance, and reproduction. Resources are distinguished as substances or objects in the environment required by one organism and consumed or otherwise made unavailable for use by other organisms. Component degradation of a substance occurs by chemical or physical processes, e.g. hydrolysis. All non-living components of an ecosystem, such as atmospheric conditions and water resources, are called abiotic components.

Ecological units refer to specific levels or degrees of organization within ecological systems. The units that are most commonly used and discussed within ecological systems are those at the levels of individuals, populations, communities, and ecosystems. These terms help distinguish between very specific, localized interactions, such as those occurring at the individual or population level, and broader, more complex interactions that occur at the community and ecosystem levels, providing a framework for understanding ecological structure and processes at different scales.

These ecological units are foundational to the field of ecology as they define and identify the key components and relationships within ecological systems at the different levels—providing cohesion in conversation and research. Additionally, these terms and the concept of ecological units as a whole are intertwined in ecological theory, understanding biodiversity, conservation strategies, and more. However, these ecological units have been met with some disagreements over the inconsistencies in the exact terminology and its uses. Arguments over stem from conflicting views from four different areas:

Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances. Chemistry also addresses the nature of chemical bonds in chemical compounds.

In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties of the soil on the Moon (cosmochemistry), how medications work (pharmacology), and how to collect DNA evidence at a crime scene (forensics).

Environmentalism is a broad philosophy, ideology, and social movement about supporting life, habitats, and surroundings. While environmentalism focuses on the environmental and nature-related aspects of green ideology and politics, ecologism combines the ideology of social ecology and environmentalism. Ecologism is a term more commonly used in continental European languages, while environmentalism is more commonly used in English, but the words have slightly different connotations.

Environmentalism advocates the preservation, restoration and improvement of the natural environment and critical earth system elements or processes such as the climate, and may be referred to as a movement to control pollution or protect plant and animal diversity. For this reason, concepts such as a land ethics, environmental ethics, biodiversity, ecology, and the biophilia hypothesis figure predominantly. The environmentalist movement encompasses various approaches to addressing environmental issues, including free market environmentalism, evangelical environmentalism, and the environmental conservation movement.

Evolutionary biology is a subfield of biology that analyzes the four mechanisms of evolution: natural selection, mutation, genetic drift, and gene flow. The purpose of evolutionary biology is to observe the diversity of life on Earth. The idea of natural selection was first researched by Charles Darwin as he studied bird beaks. The discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology. Huxley was able to take what Charles Darwin discovered and elaborate to build on his understandings.

The investigational range of current research has widened to encompass the genetic architecture of adaptation, molecular evolution, and the different forces that contribute to evolution, such as sexual selection, genetic drift, and biogeography. The newer field of evolutionary developmental biology ("evo-devo") investigates how embryogenesis is controlled, thus yielding a wider synthesis that integrates developmental biology with the fields of study covered by the earlier evolutionary synthesis.

A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creation of a river delta occurs at the river mouth, where the river merges into an ocean, a sea, or an estuary, into a lake, a reservoir, or (more rarely) into another river that cannot carry away the sediment supplied by the feeding river. Etymologically, the term river delta derives from the triangular shape (Δ) of the uppercase Greek letter delta. In hydrology, the dimensions of a river delta are determined by the balance between the watershed processes that supply sediment and the watershed processes that redistribute, sequester, and export the supplied sediment into the receiving basin.

River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide coastline defence and can impact drinking water supply. They are also ecologically important, with different species' assemblages depending on their landscape position. On geologic timescales, they are also important carbon sinks.

A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a riparian zone. The word riparian is derived from Latin ripa, meaning "river bank".

Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants. Riparian zones are important in ecology, environmental resource management, and civil engineering because of their role in soil conservation, their habitat biodiversity, and the influence they have on terrestrial and semiaquatic fauna as well as aquatic ecosystems, including grasslands, woodlands, wetlands, and even non-vegetative areas.

Paleontology or palaeontology is the scientific study of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geologic time, and assess the interactions between prehistoric organisms and their natural environment. While paleontological observations are known from at least the 6th century BC, the foundation of paleontology as a science dates back to the work of Georges Cuvier in 1796. Cuvier demonstrated evidence for the concept of extinction and how the life of the past was not necessarily the same as that of the present. The field developed rapidly over the course of the following decades, and the French word paléontologie was introduced for the study in 1822, which was derived from the Ancient Greek word for 'ancient' and words describing relatedness and a field of study. Further advances in the field accompanied the work of Charles Darwin who popularized the concept of evolution. Together, evolution and extinction can be understood as complementary processes that shaped the history of life.

Paleontology overlaps the most with the fields of geology and biology. It draws on technology and analysis of a wide range of sciences to apply them to the study of life and environments of the past, particularly for the subdisciplines of paleobiology and paleoecology that are analogous to biology and ecology. Paleontology also contributes to other sciences, being utilized for biostratigraphy to reconstruct the geologic time scale of Earth, or in studies on extinction to establish both external and internal factors that can lead to the disappearance of a species. Much of the history of life is now better understood because of advances in paleontology and the increase in interdisciplinary studies. Several improvements in understanding have occurred from the introduction of theoretical analysis to paleontology in the 1950s and 1960s which led to the rise of more focused fields of paleontology that assess the changing geography and climate of Earth, the phylogenetic relationships between different species, and the analysis of how fossilization occurs and what biases can impact the quality of the fossil record.

Colonisation or colonization is the spread and development of an organism in a new area or habitat. Colonization comprises the physical arrival of a species in a new area, but also its successful establishment within the local community. In ecology, it is represented by the symbol λ (lowercase lambda) to denote the long-term intrinsic growth rate of a population.

Surrounding theories and applicable process have been introduced below. These include dispersal, colonisation-competition trade off and prominent examples that have been previously studied.

Henry David Thoreau (born David Henry Thoreau; July 12, 1817 – May 6, 1862) was an American naturalist, essayist, poet, and philosopher. A leading transcendentalist, he is best known for his book Walden, a reflection upon simple living in natural surroundings, and his essay "Civil Disobedience" (originally published as "Resistance to Civil Government"), an argument in favor of citizen disobedience against an unjust state.

Thoreau's books, articles, essays, journals, and poetry amount to more than 20 volumes. Among his lasting contributions are his writings on natural history and philosophy, in which he anticipated the methods and findings of ecology and environmental history, two sources of modern-day environmentalism. His literary style interweaves close observation of nature, personal experience, pointed rhetoric, symbolic meanings, and historical lore, while displaying a poetic sensibility, philosophical austerity, and attention to practical detail. He was also deeply interested in the idea of survival in the face of hostile elements, historical change, and natural decay; at the same time he advocated abandoning waste and illusion in order to discover life's true essential needs.

The northern region of Europe has several definitions. A restrictive definition may describe northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54°N, or may be based on other geographical factors such as climate and ecology.

Sustainable living describes a lifestyle that attempts to reduce the use of Earth's natural resources by an individual or society. Its practitioners often attempt to reduce their ecological footprint (including their carbon footprint) by altering their home designs and methods of transportation, energy consumption and diet. Its proponents aim to conduct their lives in ways that are consistent with sustainability, naturally balanced, and respectful of humanity's symbiotic relationship with the Earth's natural ecology. The practice and general philosophy of ecological living closely follows the overall principles of sustainable development.

One approach to sustainable living, exemplified by small-scale urban transition towns and rural ecovillages, seeks to create self-reliant communities based on principles of simple living, which maximize self-sufficiency, particularly in food production. These principles, on a broader scale, underpin the concept of a bioregional economy.

In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate.

The physical factors may include (for example): soil, moisture, range of temperature, and light intensity. Biotic factors include the availability of food and the presence or absence of predators. Every species has particular habitat requirements, habitat generalist species are able to thrive in a wide array of environmental conditions while habitat specialist species require a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss; a parasitic organism has as its habitat the body of its host, part of the host's body (such as the digestive tract), or a single cell within the host's body.