Nature

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Lightning strikes during the eruption of the Galunggung volcano, West Java, in 1982
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Life in the abyssal oceans

Nature, in the broadest sense, is the natural, physical, or material world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena.

Universe Universe events since the Big Bang 13.8 billion years ago

The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. While the spatial size of the entire Universe is unknown, it is possible to measure the size of the observable universe, which is currently estimated to be 93 billion light years in diameter. In various multiverse hypotheses, a universe is one of many causally disconnected constituent parts of a larger multiverse, which itself comprises all of space and time and its contents.

Phenomenon philosophical concept

A phenomenon is any thing which manifests itself. Phenomena are often, but not always, understood as "things that appear" or "experiences" for a sentient being, or in principle may be so.

Science systematic enterprise that builds and organizes knowledge

Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.

Contents

The word nature is derived from the Latin word natura, or "essential qualities, innate disposition", and in ancient times, literally meant "birth". [1] Natura is a Latin translation of the Greek word physis (φύσις), which originally related to the intrinsic characteristics that plants, animals, and other features of the world develop of their own accord. [2] [3] The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word φύσις by pre-Socratic philosophers, and has steadily gained currency ever since. This usage continued during the advent of modern scientific method in the last several centuries. [4] [5]

Latin Indo-European language of the Italic family

Latin is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets and ultimately from the Phoenician alphabet.

Physis is a Greek theological, philosophical, and scientific term usually translated into English as "nature".

Pre-Socratic philosophy philosophical school

A number of early Greek philosophers active before and during the time of Socrates are collectively known as the pre-Socratics. Their inquiries spanned the workings of the natural world as well as human society, ethics, and religion, seeking explanations based on natural principles rather than the actions of supernatural gods. They introduced to the West the notion of the world as a kosmos, an ordered arrangement that could be understood via rational inquiry.

Within the various uses of the word today, "nature" often refers to geology and wildlife. Nature can refer to the general realm of living plants and animals, and in some cases to the processes associated with inanimate objects—the way that particular types of things exist and change of their own accord, such as the weather and geology of the Earth. It is often taken to mean the "natural environment" or wilderness—wild animals, rocks, forest, and in general those things that have not been substantially altered by human intervention, or which persist despite human intervention. For example, manufactured objects and human interaction generally are not considered part of nature, unless qualified as, for example, "human nature" or "the whole of nature". This more traditional concept of natural things which can still be found today implies a distinction between the natural and the artificial, with the artificial being understood as that which has been brought into being by a human consciousness or a human mind. Depending on the particular context, the term "natural" might also be distinguished from the unnatural or the supernatural.

Wildlife undomesticated organisms that grow or live wild in an area without being introduced by humans

Wildlife traditionally refers to undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife can be found in all ecosystems. Deserts, forests, rain forests, plains, grasslands and other areas including the most developed urban areas, all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that much wildlife is affected by human activities.

Earth Third planet from the Sun in the Solar System

Earth is the third planet from the Sun, and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space, the Moon, Earth's only natural satellite. Earth orbits around the Sun in 365.26 days, a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times.

Natural environment All living and non-living things occurring naturally, generally on Earth

The natural environment encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to the Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity. The concept of the natural environment can be distinguished as components:

Earth

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View of the Earth, taken in 1972 by the crew of Apollo 17. The Earth seen from Apollo 17.jpg
View of the Earth, taken in 1972 by the crew of Apollo 17.

Earth is the only planet known to support life, and its natural features are the subject of many fields of scientific research. Within the solar system, it is third closest to the sun; it is the largest terrestrial planet and the fifth largest overall. Its most prominent climatic features are its two large polar regions, two relatively narrow temperate zones, and a wide equatorial tropical to subtropical region. [6] Precipitation varies widely with location, from several metres of water per year to less than a millimetre. 71 percent of the Earth's surface is covered by salt-water oceans. The remainder consists of continents and islands, with most of the inhabited land in the Northern Hemisphere.

Planet Class of astronomical body directly orbiting a star or stellar remnant

A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.

Terrestrial planet planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars

A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth, as these planets are, in terms of structure, "Earth-like". These planets are located between the Sun and the asteroid belt.

Equator Intersection of a spheres surface with the plane perpendicular to the spheres axis of rotation and midway between the poles

An equator of a rotating spheroid is its zeroth circle of latitude (parallel). It is the imaginary line on the spheroid, equidistant from its poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles.

Earth has evolved through geological and biological processes that have left traces of the original conditions. The outer surface is divided into several gradually migrating tectonic plates. The interior remains active, with a thick layer of plastic mantle and an iron-filled core that generates a magnetic field. This iron core is composed of a solid inner phase, and a fluid outer phase. Convective motion in the core generates electric currents through dynamo action, and these, in turn, generate the geomagnetic field.

Crust (geology) The outermost solid shell of a rocky planet, dwarf planet, or natural satellite

In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase.

A mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density. All terrestrial planets, a number of asteroids, and some planetary moons have mantles.

Magnetic field spatial distribution of vectors allowing the calculation of the magnetic force on a test particle

A magnetic field is a vector field that describes the magnetic influence of electric charges in relative motion and magnetized materials. Magnetic fields are observed in a wide range of size scales, from subatomic particles to galaxies. In everyday life, the effects of magnetic fields are often seen in permanent magnets, which pull on magnetic materials and attract or repel other magnets. Magnetic fields surround and are created by magnetized material and by moving electric charges such as those used in electromagnets. Magnetic fields exert forces on nearby moving electrical charges and torques on nearby magnets. In addition, a magnetic field that varies with location exerts a force on magnetic materials. Both the strength and direction of a magnetic field vary with location. As such, it is an example of a vector field.

The atmospheric conditions have been significantly altered from the original conditions by the presence of life-forms, [7] which create an ecological balance that stabilizes the surface conditions. Despite the wide regional variations in climate by latitude and other geographic factors, the long-term average global climate is quite stable during interglacial periods, [8] and variations of a degree or two of average global temperature have historically had major effects on the ecological balance, and on the actual geography of the Earth. [9] [10]

Atmosphere The layer of gases surrounding an astronomical body held by gravity

An atmosphere is a layer or a set of layers of gases surrounding a planet or other material body, that is held in place by the gravity of that body. An atmosphere is more likely to be retained if the gravity it is subject to is high and the temperature of the atmosphere is low.

Latitude The angle between zenith at a point and the plane of the equator

In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earth's surface. Latitude is an angle which ranges from 0° at the Equator to 90° at the poles. Lines of constant latitude, or parallels, run east–west as circles parallel to the equator. Latitude is used together with longitude to specify the precise location of features on the surface of the Earth. On its own, the term latitude should be taken to be the geodetic latitude as defined below. Briefly, geodetic latitude at a point is the angle formed by the vector perpendicular to the ellipsoidal surface from that point, and the equatorial plane. Also defined are six auxiliary latitudes which are used in special applications.

Geology

Geology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, structure, physical properties, dynamics, and history of Earth materials, and the processes by which they are formed, moved, and changed. The field is a major academic discipline, and is also important for mineral and hydrocarbon extraction, knowledge about and mitigation of natural hazards, some Geotechnical engineering fields, and understanding past climates and environments.

Geological evolution

Three types of geological plate tectonic boundaries. Tectonic plate boundaries.png
Three types of geological plate tectonic boundaries.

The geology of an area evolves through time as rock units are deposited and inserted and deformational processes change their shapes and locations.

Rock units are first emplaced either by deposition onto the surface or intrude into the overlying rock. Deposition can occur when sediments settle onto the surface of the Earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows, blanket the surface. Igneous intrusions such as batholiths, laccoliths, dikes, and sills, push upwards into the overlying rock, and crystallize as they intrude.

After the initial sequence of rocks has been deposited, the rock units can be deformed and/or metamorphosed. Deformation typically occurs as a result of horizontal shortening, horizontal extension, or side-to-side (strike-slip) motion. These structural regimes broadly relate to convergent boundaries, divergent boundaries, and transform boundaries, respectively, between tectonic plates.

Historical perspective

An animation showing the movement of the continents from the separation of Pangaea until the present day. Pangea animation 03.gif
An animation showing the movement of the continents from the separation of Pangaea until the present day.

Earth is estimated to have formed 4.54 billion years ago from the solar nebula, along with the Sun and other planets. [11] The moon formed roughly 20 million years later. Initially molten, the outer layer of the Earth cooled, resulting in the solid crust. Outgassing and volcanic activity produced the primordial atmosphere. Condensing water vapor, most or all of which came from ice delivered by comets, produced the oceans and other water sources. [12] The highly energetic chemistry is believed to have produced a self-replicating molecule around 4 billion years ago. [13]

Plankton inhabit oceans, seas and lakes, and have existed in various forms for at least 2 billion years. Hyperia.jpg
Plankton inhabit oceans, seas and lakes, and have existed in various forms for at least 2 billion years.

Continents formed, then broke up and reformed as the surface of Earth reshaped over hundreds of millions of years, occasionally combining to make a supercontinent. Roughly 750 million years ago, the earliest known supercontinent Rodinia, began to break apart. The continents later recombined to form Pannotia which broke apart about 540 million years ago, then finally Pangaea, which broke apart about 180 million years ago. [15]

During the Neoproterozoic era, freezing temperatures covered much of the Earth in glaciers and ice sheets. This hypothesis has been termed the "Snowball Earth", and it is of particular interest as it precedes the Cambrian explosion in which multicellular life forms began to proliferate about 530–540 million years ago. [16]

Since the Cambrian explosion there have been five distinctly identifiable mass extinctions. [17] The last mass extinction occurred some 66 million years ago, when a meteorite collision probably triggered the extinction of the non-avian dinosaurs and other large reptiles, but spared small animals such as mammals. Over the past 66 million years, mammalian life diversified. [18]

Several million years ago, a species of small African ape gained the ability to stand upright. [14] The subsequent advent of human life, and the development of agriculture and further civilization allowed humans to affect the Earth more rapidly than any previous life form, affecting both the nature and quantity of other organisms as well as global climate. By comparison, the Great Oxygenation Event, produced by the proliferation of algae during the Siderian period, required about 300 million years to culminate.

The present era is classified as part of a mass extinction event, the Holocene extinction event, the fastest ever to have occurred. [19] [20] Some, such as E. O. Wilson of Harvard University, predict that human destruction of the biosphere could cause the extinction of one-half of all species in the next 100 years. [21] The extent of the current extinction event is still being researched, debated and calculated by biologists. [22] [23] [24]

Atmosphere, climate, and weather

Blue light is scattered more than other wavelengths by the gases in the atmosphere, giving the Earth a blue halo when seen from space Top of Atmosphere.jpg
Blue light is scattered more than other wavelengths by the gases in the atmosphere, giving the Earth a blue halo when seen from space

The Earth's atmosphere is a key factor in sustaining the ecosystem. The thin layer of gases that envelops the Earth is held in place by gravity. Air is mostly nitrogen, oxygen, water vapor, with much smaller amounts of carbon dioxide, argon, etc. The atmospheric pressure declines steadily with altitude. The ozone layer plays an important role in depleting the amount of ultraviolet (UV) radiation that reaches the surface. As DNA is readily damaged by UV light, this serves to protect life at the surface. The atmosphere also retains heat during the night, thereby reducing the daily temperature extremes.

Terrestrial weather occurs almost exclusively in the lower part of the atmosphere, and serves as a convective system for redistributing heat. [25] Ocean currents are another important factor in determining climate, particularly the major underwater thermohaline circulation which distributes heat energy from the equatorial oceans to the polar regions. These currents help to moderate the differences in temperature between winter and summer in the temperate zones. Also, without the redistributions of heat energy by the ocean currents and atmosphere, the tropics would be much hotter, and the polar regions much colder.

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Lightning

Weather can have both beneficial and harmful effects. Extremes in weather, such as tornadoes or hurricanes and cyclones, can expend large amounts of energy along their paths, and produce devastation. Surface vegetation has evolved a dependence on the seasonal variation of the weather, and sudden changes lasting only a few years can have a dramatic effect, both on the vegetation and on the animals which depend on its growth for their food.

Climate is a measure of the long-term trends in the weather. Various factors are known to influence the climate, including ocean currents, surface albedo, greenhouse gases, variations in the solar luminosity, and changes to the Earth's orbit. Based on historical records, the Earth is known to have undergone drastic climate changes in the past, including ice ages.

A tornado in central Oklahoma Dszpics1.jpg
A tornado in central Oklahoma

The climate of a region depends on a number of factors, especially latitude. A latitudinal band of the surface with similar climatic attributes forms a climate region. There are a number of such regions, ranging from the tropical climate at the equator to the polar climate in the northern and southern extremes. Weather is also influenced by the seasons, which result from the Earth's axis being tilted relative to its orbital plane. Thus, at any given time during the summer or winter, one part of the Earth is more directly exposed to the rays of the sun. This exposure alternates as the Earth revolves in its orbit. At any given time, regardless of season, the northern and southern hemispheres experience opposite seasons.

Weather is a chaotic system that is readily modified by small changes to the environment, so accurate weather forecasting is limited to only a few days. [26] Overall, two things are happening worldwide: (1) temperature is increasing on the average; and (2) regional climates have been undergoing noticeable changes. [27]

Water on Earth

The Iguazu Falls on the border between Brazil and Argentina 44 - Iguazu - Decembre 2007.jpg
The Iguazu Falls on the border between Brazil and Argentina

Water is a chemical substance that is composed of hydrogen and oxygen and is vital for all known forms of life. [28] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor, or steam. Water covers 71% of the Earth's surface. [29] On Earth, it is found mostly in oceans and other large bodies of water, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds, and precipitation. [30] [31] Oceans hold 97% of surface water, glaciers, and polar ice caps 2.4%, and other land surface water such as rivers, lakes, and ponds 0.6%. Additionally, a minute amount of the Earth's water is contained within biological bodies and manufactured products.

Oceans

A view of the Atlantic Ocean from Leblon, Rio de Janeiro. Ocean from Leblon.jpg
A view of the Atlantic Ocean from Leblon, Rio de Janeiro.

An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface (an area of some 361 million square kilometers) is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas. More than half of this area is over 3,000 meters (9,800 feet) deep. Average oceanic salinity is around 35 parts per thousand (ppt) (3.5%), and nearly all seawater has a salinity in the range of 30 to 38 ppt. Though generally recognized as several 'separate' oceans, these waters comprise one global, interconnected body of salt water often referred to as the World Ocean or global ocean. [32] [33] This concept of a global ocean as a continuous body of water with relatively free interchange among its parts is of fundamental importance to oceanography. [34]

The major oceanic divisions are defined in part by the continents, various archipelagos, and other criteria: these divisions are (in descending order of size) the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean. Smaller regions of the oceans are called seas, gulfs, bays and other names. There are also salt lakes, which are smaller bodies of landlocked saltwater that are not interconnected with the World Ocean. Two notable examples of salt lakes are the Aral Sea and the Great Salt Lake.

Lakes

Lake Mapourika, New Zealand Lake mapourika NZ.jpeg
Lake Mapourika, New Zealand

A lake (from Latin lacus) is a terrain feature (or physical feature), a body of liquid on the surface of a world that is localized to the bottom of basin (another type of landform or terrain feature; that is, it is not global) and moves slowly if it moves at all. On Earth, a body of water is considered a lake when it is inland, not part of the ocean, is larger and deeper than a pond, and is fed by a river. [35] [36] The only world other than Earth known to harbor lakes is Titan, Saturn's largest moon, which has lakes of ethane, most likely mixed with methane. It is not known if Titan's lakes are fed by rivers, though Titan's surface is carved by numerous river beds. Natural lakes on Earth are generally found in mountainous areas, rift zones, and areas with ongoing or recent glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world, there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them.

Ponds

The Westborough Reservoir (Mill Pond) in Westborough, Massachusetts. Mill Pond Sunset.jpg
The Westborough Reservoir (Mill Pond) in Westborough, Massachusetts.

A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens designed for aesthetic ornamentation, fish ponds designed for commercial fish breeding, and solar ponds designed to store thermal energy. Ponds and lakes are distinguished from streams via current speed. While currents in streams are easily observed, ponds and lakes possess thermally driven micro-currents and moderate wind driven currents. These features distinguish a pond from many other aquatic terrain features, such as stream pools and tide pools.

Rivers

The Nile river in Cairo, Egypt's capital city View from Cairo Tower 31march2007.jpg
The Nile river in Cairo, Egypt's capital city

A river is a natural watercourse, [37] usually freshwater, flowing toward an ocean, a lake, a sea or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including stream, creek, brook, rivulet, and rill; there is no general rule that defines what can be called a river. Many names for small rivers are specific to geographic location; one example is Burn in Scotland and North-east England. Sometimes a river is said to be larger than a creek, but this is not always the case, due to vagueness in the language. [38] A river is part of the hydrological cycle. Water within a river is generally collected from precipitation through surface runoff, groundwater recharge, springs, and the release of stored water in natural ice and snowpacks (i.e., from glaciers).

Streams

A rocky stream in Hawaii Hawaii Creek.jpg
A rocky stream in Hawaii

A stream is a flowing body of water with a current, confined within a bed and stream banks. In the United States, a stream is classified as a watercourse less than 60 feet (18 metres) wide. Streams are important as conduits in the water cycle, instruments in groundwater recharge, and they serve as corridors for fish and wildlife migration. The biological habitat in the immediate vicinity of a stream is called a riparian zone. Given the status of the ongoing Holocene extinction, streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity. The study of streams and waterways in general involves many branches of inter-disciplinary natural science and engineering, including hydrology, fluvial geomorphology, aquatic ecology, fish biology, riparian ecology, and others.

Ecosystems

Loch Lomond in Scotland forms a relatively isolated ecosystem. The fish community of this lake has remained unchanged over a very long period of time. View of loch lomond.JPG
Loch Lomond in Scotland forms a relatively isolated ecosystem. The fish community of this lake has remained unchanged over a very long period of time.
Lush green Aravalli Mountain Range in the Desert country - Rajasthan, India. A wonder how such greenery can exist in hot Rajasthan, a place well known for its Thar Desert Aravalli.jpg
Lush green Aravalli Mountain Range in the Desert country – Rajasthan, India. A wonder how such greenery can exist in hot Rajasthan, a place well known for its Thar Desert
An aerial view of a human ecosystem. Pictured is the city of Chicago Chicago Downtown Aerial View.jpg
An aerial view of a human ecosystem. Pictured is the city of Chicago

Ecosystems are composed of a variety of abiotic and biotic components that function in an interrelated way. [40] The structure and composition is determined by various environmental factors that are interrelated. Variations of these factors will initiate dynamic modifications to the ecosystem. Some of the more important components are: soil, atmosphere, radiation from the sun, water, and living organisms.

Penas Blancas, part of the Bosawas Biosphere Reserve. Located northeast of the city of Jinotega in Northeastern Nicaragua. PenasBlancas, part of the Bosawas Reserve, Jinotega Department, Nicaragua.jpg
Peñas Blancas, part of the Bosawás Biosphere Reserve. Located northeast of the city of Jinotega in Northeastern Nicaragua.

Central to the ecosystem concept is the idea that living organisms interact with every other element in their local environment. Eugene Odum, a founder of ecology, stated: "Any unit that includes all of the organisms (ie: the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (i.e.: exchange of materials between living and nonliving parts) within the system is an ecosystem." [41] Within the ecosystem, species are connected and dependent upon one another in the food chain, and exchange energy and matter between themselves as well as with their environment. [42] The human ecosystem concept is based on the human/nature dichotomy and the idea that all species are ecologically dependent on each other, as well as with the abiotic constituents of their biotope. [43]

A smaller unit of size is called a microecosystem. For example, a microsystem can be a stone and all the life under it. A macroecosystem might involve a whole ecoregion, with its drainage basin. [44]

Wilderness

Old growth European Beech forest in Biogradska Gora National Park, Montenegro. Biogradska suma.jpg
Old growth European Beech forest in Biogradska Gora National Park, Montenegro.

Wilderness is generally defined as areas that have not been significantly modified by human activity. Wilderness areas can be found in preserves, estates, farms, conservation preserves, ranches, national forests, national parks, and even in urban areas along rivers, gulches, or otherwise undeveloped areas. Wilderness areas and protected parks are considered important for the survival of certain species, ecological studies, conservation, and solitude. Some nature writers believe wilderness areas are vital for the human spirit and creativity, [45] and some ecologists consider wilderness areas to be an integral part of the Earth's self-sustaining natural ecosystem (the biosphere). They may also preserve historic genetic traits and that they provide habitat for wild flora and fauna that may be difficult or impossible to recreate in zoos, arboretums, or laboratories.

Life

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Female mallard and ducklings - reproduction is essential for continuing life Malards in Golden Gate Park.jpg
Female mallard and ducklings – reproduction is essential for continuing life

Although there is no universal agreement on the definition of life, scientists generally accept that the biological manifestation of life is characterized by organization, metabolism, growth, adaptation, response to stimuli, and reproduction. [46] Life may also be said to be simply the characteristic state of organisms.

Properties common to terrestrial organisms (plants, animals, fungi, protists, archaea, and bacteria) are that they are cellular, carbon-and-water-based with complex organization, having a metabolism, a capacity to grow, respond to stimuli, and reproduce. An entity with these properties is generally considered life. However, not every definition of life considers all of these properties to be essential. Human-made analogs of life may also be considered to be life.

The biosphere is the part of Earth's outer shell—including land, surface rocks, water, air and the atmosphere—within which life occurs, and which biotic processes in turn alter or transform. From the broadest geophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere (rocks), hydrosphere (water), and atmosphere (air). The entire Earth contains over 75 billion tons (150 trillion pounds or about 6.8×1013 kilograms) of biomass (life), which lives within various environments within the biosphere. [47]

Over nine-tenths of the total biomass on Earth is plant life, on which animal life depends very heavily for its existence. [48] More than 2 million species of plant and animal life have been identified to date, [49] and estimates of the actual number of existing species range from several million to well over 50 million. [50] [51] [52] The number of individual species of life is constantly in some degree of flux, with new species appearing and others ceasing to exist on a continual basis. [53] [54] The total number of species is in rapid decline. [55] [56] [57]

Evolution

An area of the Amazon Rainforest shared between Colombia and Brazil. The tropical rainforests of South America contain the largest diversity of species on Earth. Amazon Manaus forest.jpg
An area of the Amazon Rainforest shared between Colombia and Brazil. The tropical rainforests of South America contain the largest diversity of species on Earth.

The origin of life on Earth is not well understood, but it is known to have occurred at least 3.5 billion years ago, [60] [61] [62] during the hadean or archean eons on a primordial Earth that had a substantially different environment than is found at present. [63] These life forms possessed the basic traits of self-replication and inheritable traits. Once life had appeared, the process of evolution by natural selection resulted in the development of ever-more diverse life forms.

Species that were unable to adapt to the changing environment and competition from other life forms became extinct. However, the fossil record retains evidence of many of these older species. Current fossil and DNA evidence shows that all existing species can trace a continual ancestry back to the first primitive life forms. [63]

When basic forms of plant life developed the process of photosynthesis the sun's energy could be harvested to create conditions which allowed for more complex life forms. [64] The resultant oxygen accumulated in the atmosphere and gave rise to the ozone layer. The incorporation of smaller cells within larger ones resulted in the development of yet more complex cells called eukaryotes. [65] Cells within colonies became increasingly specialized, resulting in true multicellular organisms. With the ozone layer absorbing harmful ultraviolet radiation, life colonized the surface of Earth.

Microbes

A microscopic mite Lorryia formosa. Yellow mite (Tydeidae) Lorryia formosa 2 edit.jpg
A microscopic mite Lorryia formosa .

The first form of life to develop on the Earth were microbes, and they remained the only form of life until about a billion years ago when multi-cellular organisms began to appear. [66] Microorganisms are single-celled organisms that are generally microscopic, and smaller than the human eye can see. They include Bacteria, Fungi, Archaea, and Protista.

These life forms are found in almost every location on the Earth where there is liquid water, including in the Earth's interior. [67] Their reproduction is both rapid and profuse. The combination of a high mutation rate and a horizontal gene transfer [68] ability makes them highly adaptable, and able to survive in new environments, including outer space. [69] They form an essential part of the planetary ecosystem. However, some microorganisms are pathogenic and can post health risk to other organisms.

Plants and animals

A selection of diverse plant species Diversity of plants image version 5.png
A selection of diverse plant species
A selection of diverse animal species Animal diversity.png
A selection of diverse animal species

Originally Aristotle divided all living things between plants, which generally do not move fast enough for humans to notice, and animals. In Linnaeus' system, these became the kingdoms Vegetabilia (later Plantae) and Animalia. Since then, it has become clear that the Plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. However, these are still often considered plants in many contexts. Bacterial life is sometimes included in flora, [70] [71] and some classifications use the term bacterial flora separately from plant flora.

Among the many ways of classifying plants are by regional floras, which, depending on the purpose of study, can also include fossil flora, remnants
of plant life from a previous era. People in many regions and countries take great pride in their individual arrays of characteristic flora, which can vary widely across the globe due to differences in climate and terrain.

Regional floras commonly are divided into categories such as native flora and agricultural and garden flora, the lastly mentioned of which are intentionally grown and cultivated. Some types of "native flora" actually have been introduced centuries ago by people migrating from one region or continent to another, and become an integral part of the native, or natural flora of the place to which they were introduced. This is an example of how human interaction with nature can blur the boundary of what is considered nature.

Another category of plant has historically been carved out for weeds. Though the term has fallen into disfavor among botanists as a formal way to categorize "useless" plants, the informal use of the word "weeds" to describe those plants that are deemed worthy of elimination is illustrative of the general tendency of people and societies to seek to alter or shape the course of nature. Similarly, animals are often categorized in ways such as domestic, farm animals, wild animals, pests, etc. according to their relationship to human life.

Animals as a category have several characteristics that generally set them apart from other living things. Animals are eukaryotic and usually multicellular (although see Myxozoa), which separates them from bacteria, archaea, and most protists. They are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls.

With a few exceptions—most notably the two phyla consisting of sponges and placozoans—animals have bodies that are differentiated into tissues. These include muscles, which are able to contract and control locomotion, and a nervous system, which sends and processes signals. There is also typically an internal digestive chamber. The eukaryotic cells possessed by all animals are surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. This may be calcified to form structures like shells, bones, and spicules, a framework upon which cells can move about and be reorganized during development and maturation, and which supports the complex anatomy required for mobility.

Human interrelationship

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Despite their natural beauty, the secluded valleys along the Na Pali Coast in Hawaii are heavily modified by introduced invasive species such as She-oak. Na Pali Coast - Kauai.jpg
Despite their natural beauty, the secluded valleys along the Na Pali Coast in Hawaii are heavily modified by introduced invasive species such as She-oak.

Although humans comprise only a minuscule proportion of the total living biomass on Earth, the human effect on nature is disproportionately large. Because of the extent of human influence, the boundaries between what humans regard as nature and "made environments" is not clear cut except at the extremes. Even at the extremes, the amount of natural environment that is free of discernible human influence is diminishing at an increasingly rapid pace.

The development of technology by the human race has allowed the greater exploitation of natural resources and has helped to alleviate some of the risk from natural hazards. In spite of this progress, however, the fate of human civilization remains closely linked to changes in the environment. There exists a highly complex feedback loop between the use of advanced technology and changes to the environment that are only slowly becoming understood. [72] Man-made threats to the Earth's natural environment include pollution, deforestation, and disasters such as oil spills. Humans have contributed to the extinction of many plants and animals.

Humans employ nature for both leisure and economic activities. The acquisition of natural resources for industrial use remains a sizable component of the world's economic system. [73] [74] Some activities, such as hunting and fishing, are used for both sustenance and leisure, often by different people. Agriculture was first adopted around the 9th millennium BCE. Ranging from food production to energy, nature influences economic wealth.

Although early humans gathered uncultivated plant materials for food and employed the medicinal properties of vegetation for healing, [75] most modern human use of plants is through agriculture. The clearance of large tracts of land for crop growth has led to a significant reduction in the amount available of forestation and wetlands, resulting in the loss of habitat for many plant and animal species as well as increased erosion. [76]

Aesthetics and beauty

Pinguicula grandiflora, commonly known as a Butterwort 504px-Pinguiculagrandiflora1web.jpg
Pinguicula grandiflora , commonly known as a Butterwort
Aesthetically pleasing flowers Cyclamen coum (d.j.b.) 02.jpg
Aesthetically pleasing flowers

Beauty in nature has historically been a prevalent theme in art and books, filling large sections of libraries and bookstores. That nature has been depicted and celebrated by so much art, photography, poetry, and other literature shows the strength with which many people associate nature and beauty. Reasons why this association exists, and what the association consists of, are studied by the branch of philosophy called aesthetics. Beyond certain basic characteristics that many philosophers agree about to explain what is seen as beautiful, the opinions are virtually endless. [77] Nature and wildness have been important subjects in various eras of world history. An early tradition of landscape art began in China during the Tang Dynasty (618–907). The tradition of representing nature as it is became one of the aims of Chinese painting and was a significant influence in Asian art.

Although natural wonders are celebrated in the Psalms and the Book of Job, wilderness portrayals in art became more prevalent in the 1800s, especially in the works of the Romantic movement. British artists John Constable and J. M. W. Turner turned their attention to capturing the beauty of the natural world in their paintings. Before that, paintings had been primarily of religious scenes or of human beings. William Wordsworth's poetry described the wonder of the natural world, which had formerly been viewed as a threatening place. Increasingly the valuing of nature became an aspect of Western culture. [78] This artistic movement also coincided with the Transcendentalist movement in the Western world. A common classical idea of beautiful art involves the word mimesis, the imitation of nature. Also in the realm of ideas about beauty in nature is that the perfect is implied through perfect mathematical forms and more generally by patterns in nature. As David Rothenburg writes, "The beautiful is the root of science and the goal of art, the highest possibility that humanity can ever hope to see". [79] :281

Matter and energy

The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density Hydrogen Density Plots.png
The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density

Some fields of science see nature as matter in motion, obeying certain laws of nature which science seeks to understand. For this reason the most fundamental science is generally understood to be "physics"—the name for which is still recognizable as meaning that it is the study of nature.

Matter is commonly defined as the substance of which physical objects are composed. It constitutes the observable universe. The visible components of the universe are now believed to compose only 4.9 percent of the total mass. The remainder is believed to consist of 26.8 percent cold dark matter and 68.3 percent dark energy. [80] The exact arrangement of these components is still unknown and is under intensive investigation by physicists.

The behavior of matter and energy throughout the observable universe appears to follow well-defined physical laws. These laws have been employed to produce cosmological models that successfully explain the structure and the evolution of the universe we can observe. The mathematical expressions of the laws of physics employ a set of twenty physical constants [81] that appear to be static across the observable universe. [82] The values of these constants have been carefully measured, but the reason for their specific values remains a mystery.

Beyond Earth

Planets of the Solar System (Sizes to scale, distances and illumination not to scale) Planets2013.jpg
Planets of the Solar System (Sizes to scale, distances and illumination not to scale)
NGC 4414 is a spiral galaxy in the constellation Coma Berenices about 56,000 light-years in diameter and approximately 60 million light-years from Earth NGC 4414 (NASA-med).jpg
NGC 4414 is a spiral galaxy in the constellation Coma Berenices about 56,000 light-years in diameter and approximately 60 million light-years from Earth

Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace (and terrestrial locations). There is no discrete boundary between the Earth's atmosphere and space, as the atmosphere gradually attenuates with increasing altitude. Outer space within the Solar System is called interplanetary space, which passes over into interstellar space at what is known as the heliopause.

Outer space is sparsely filled with several dozen types of organic molecules discovered to date by microwave spectroscopy, blackbody radiation left over from the big bang and the origin of the universe, and cosmic rays, which include ionized atomic nuclei and various subatomic particles. There is also some gas, plasma and dust, and small meteors. Additionally, there are signs of human life in outer space today, such as material left over from previous manned and unmanned launches which are a potential hazard to spacecraft. Some of this debris re-enters the atmosphere periodically.

Although the Earth is the only body within the solar system known to support life, evidence suggests that in the distant past the planet Mars possessed bodies of liquid water on the surface. [83] For a brief period in Mars' history, it may have also been capable of forming life. At present though, most of the water remaining on Mars is frozen. If life exists at all on Mars, it is most likely to be located underground where liquid water can still exist. [84]

Conditions on the other terrestrial planets, Mercury and Venus, appear to be too harsh to support life as we know it. But it has been conjectured that Europa, the fourth-largest moon of Jupiter, may possess a sub-surface ocean of liquid water and could potentially host life. [85]

Astronomers have started to discover extrasolar Earth analogs – planets that lie in the habitable zone of space surrounding a star, and therefore could possibly host life as we know it. [86]

See also

Media:

Organizations:

Philosophy:

Notes and references

  1. Harper, Douglas. "nature". Online Etymology Dictionary . Retrieved September 23, 2006.
  2. An account of the pre-Socratic use of the concept of φύσις may be found in Naddaf, Gerard (2006) The Greek Concept of Nature, SUNY Press. The word φύσις, while first used in connection with a plant in Homer, occurs very early in Greek philosophy, and in several senses. Generally, these senses match rather well the current senses in which the English word nature is used, as confirmed by Guthrie, W.K.C. Presocratic Tradition from Parmenides to Democritus (volume 2 of his History of Greek Philosophy), Cambridge UP, 1965.
  3. The first known use of physis was by Homer in reference to the intrinsic qualities of a plant: ὣς ἄρα φωνήσας πόρε φάρμακον ἀργεϊφόντης ἐκ γαίης ἐρύσας, καί μοι φύσιν αὐτοῦ ἔδειξε. (So saying, Argeiphontes [=Hermes] gave me the herb, drawing it from the ground, and showed me its nature.) Odyssey 10.302–03 (ed. A.T. Murray). (The word is dealt with thoroughly in Liddell and Scott's Greek Lexicon Archived March 5, 2011, at the Wayback Machine .) For later but still very early Greek uses of the term, see earlier note.
  4. Isaac Newton's Philosophiae Naturalis Principia Mathematica (1687), for example, is translated "Mathematical Principles of Natural Philosophy", and reflects the then-current use of the words "natural philosophy", akin to "systematic study of nature"
  5. The etymology of the word "physical" shows its use as a synonym for "natural" in about the mid-15th century: Harper, Douglas. "physical". Online Etymology Dictionary . Retrieved September 20, 2006.
  6. "World Climates". Blue Planet Biomes. Archived from the original on December 17, 2008. Retrieved September 21, 2006.
  7. "Calculations favor reducing atmosphere for early Earth". Science Daily . September 11, 2005. Archived from the original on August 30, 2006. Retrieved January 6, 2007.
  8. "Past Climate Change". U.S. Environmental Protection Agency. Archived from the original on May 11, 2012. Retrieved January 7, 2007.
  9. Hugh Anderson; Bernard Walter (March 28, 1997). "History of Climate Change". NASA. Archived from the original on January 23, 2008. Retrieved January 7, 2007.
  10. Weart, Spencer (June 2006). "The Discovery of Global Warming". American Institute of Physics. Archived from the original on August 21, 2011. Retrieved January 7, 2007.
  11. Dalrymple, G. Brent (1991). The Age of the Earth. Stanford: Stanford University Press. ISBN   978-0-8047-1569-0.
  12. Morbidelli, A.; et al. (2000). "Source Regions and Time Scales for the Delivery of Water to Earth". Meteoritics & Planetary Science. 35 (6): 1309–20. Bibcode:2000M&PS...35.1309M. doi:10.1111/j.1945-5100.2000.tb01518.x.
  13. "Earth's Oldest Mineral Grains Suggest an Early Start for Life". NASA Astrobiology Institute. December 24, 2001. Archived from the original on September 28, 2006. Retrieved May 24, 2006.
  14. 1 2 Margulis, Lynn; Dorian Sagan (1995). What is Life?. New York: Simon & Schuster. ISBN   978-0-684-81326-4.
  15. Murphy, J.B.; R.D. Nance (2004). "How do supercontinents assemble?". American Scientist. 92 (4): 324. doi:10.1511/2004.4.324. Archived from the original on January 28, 2011. Retrieved August 23, 2010.
  16. Kirschvink, J.L. (1992). "Late Proterozoic Low-Latitude Global Glaciation: The Snowball Earth" (PDF). In J.W. Schopf; C. Klein (eds.). The Proterozoic Biosphere. Cambridge: Cambridge University Press. pp. 51–52. ISBN   978-0-521-36615-1.
  17. Raup, David M.; J. John Sepkoski Jr. (March 1982). "Mass extinctions in the marine fossil record". Science. 215 (4539): 1501–03. Bibcode:1982Sci...215.1501R. doi:10.1126/science.215.4539.1501. PMID   17788674.
  18. Margulis, Lynn; Dorian Sagan (1995). What is Life?. New York: Simon & Schuster. p. 145. ISBN   978-0-684-81326-4.
  19. Diamond J; Ashmole, N. P.; Purves, P. E. (1989). "The present, past and future of human-caused extinctions". Philos Trans R Soc Lond B Biol Sci. 325 (1228): 469–76, discussion 476–77. Bibcode:1989RSPTB.325..469D. doi:10.1098/rstb.1989.0100. PMID   2574887.
  20. Novacek M; Cleland E (2001). "The current biodiversity extinction event: scenarios for mitigation and recovery". Proc Natl Acad Sci USA. 98 (10): 5466–70. Bibcode:2001PNAS...98.5466N. doi:10.1073/pnas.091093698. PMC   33235 . PMID   11344295.
  21. Wick, Lucia; Möhl, Adrian (2006). "The mid-Holocene extinction of silver fir (Abies alba) in the Southern Alps: a consequence of forest fires? Palaeobotanical records and forest simulations" (PDF). Vegetation History and Archaeobotany. 15 (4): 435–44. doi:10.1007/s00334-006-0051-0. Archived (PDF) from the original on November 15, 2018. Retrieved November 15, 2018.
  22. The Holocene Extinction Archived September 25, 2006, at the Wayback Machine . Park.org. Retrieved on November 3, 2016.
  23. Mass Extinctions Of The Phanerozoic Menu Archived September 25, 2006, at the Wayback Machine . Park.org. Retrieved on November 3, 2016.
  24. Patterns of Extinction Archived September 25, 2006, at the Wayback Machine . Park.org. Retrieved on November 3, 2016.
  25. Miller, G.; Spoolman, Scott (September 28, 2007). Environmental Science: Problems, Connections and Solutions. Cengage Learning. ISBN   978-0-495-38337-6.
  26. Stern, Harvey; Davidson, Noel (May 25, 2015). "Trends in the skill of weather prediction at lead times of 1–14 days". Quarterly Journal of the Royal Meteorological Society. 141 (692): 2726–36. doi:10.1002/qj.2559 via Wiley.
  27. "Tropical Ocean Warming Drives Recent Northern Hemisphere Climate Change". Science Daily. April 6, 2001. Archived from the original on April 21, 2006. Retrieved May 24, 2006.
  28. "Water for Life". Un.org. March 22, 2005. Archived from the original on May 14, 2011. Retrieved May 14, 2011.
  29. "World". CIA – World Fact Book. Archived from the original on February 1, 2010. Retrieved December 20, 2008.
  30. Water Vapor in the Climate System, Special Report, American Geophysical Union, December 1995.
  31. Vital Water. UNEP.
  32. "Ocean Archived January 26, 2011, at the Wayback Machine ". The Columbia Encyclopedia. 2002. New York: Columbia University Press
  33. "Distribution of land and water on the planet Archived May 31, 2008, at the Wayback Machine ". UN Atlas of the Oceans Archived September 15, 2008, at the Wayback Machine
  34. Spilhaus, Athelstan F (1942). "Maps of the whole world ocean". Geographical Review. 32 (3): 431–35. doi:10.2307/210385. JSTOR   210385.
  35. Britannica Online. "Lake (physical feature)". Archived from the original on June 11, 2008. Retrieved June 25, 2008. [a Lake is] any relatively large body of slowly moving or standing water that occupies an inland basin of appreciable size. Definitions that precisely distinguish lakes, ponds, swamps, and even rivers and other bodies of nonoceanic water are not well established. It may be said, however, that rivers and streams are relatively fast moving; marshes and swamps contain relatively large quantities of grasses, trees, or shrubs; and ponds are relatively small in comparison to lakes. Geologically defined, lakes are temporary bodies of water.
  36. "Lake Definition". Dictionary.com. Archived from the original on September 5, 2016. Retrieved September 6, 2016.
  37. River {definition} Archived February 21, 2010, at the Wayback Machine from Merriam-Webster. Accessed February 2010.
  38. USGS – U.S. Geological Survey – FAQs Archived July 1, 2015, at the Wayback Machine , No. 17 What is the difference between mountain, hill, and peak; lake and pond; or river and creek?
  39. Adams, C.E. (1994). "The fish community of Loch Lomond, Scotland: its history and rapidly changing status". Hydrobiologia. 290 (1–3): 91–102. Bibcode:2004HyBio.524..167W. doi:10.1007/BF00008956. Archived from the original on January 14, 2012. Retrieved January 5, 2007.
  40. Pidwirny, Michael (2006). "Introduction to the Biosphere: Introduction to the Ecosystem Concept". Fundamentals of Physical Geography (2nd Edition). Archived from the original on August 21, 2011. Retrieved September 28, 2006.
  41. Odum, EP (1971) Fundamentals of ecology, 3rd edition, Saunders New York
  42. Pidwirny, Michael (2006). "Introduction to the Biosphere: Organization of Life". Fundamentals of Physical Geography (2nd edition). Archived from the original on August 21, 2011. Retrieved September 28, 2006.
  43. Khan, Firdos Alam (September 20, 2011). Biotechnology Fundamentals. CRC Press. ISBN   978-1-4398-2009-4.
  44. Bailey, Robert G. (April 2004). "Identifying Ecoregion Boundaries" (PDF). Environmental Management. 34 (Supplement 1): S14–26. doi:10.1007/s00267-003-0163-6. PMID   15883869. Archived from the original (PDF) on December 4, 2009.
  45. Botkin, Daniel B. (2000) No Man's Garden, Island Press, pp. 155–57, ISBN   1-55963-465-0.
  46. "Definition of Life". California Academy of Sciences. 2006. Archived from the original on February 8, 2007. Retrieved January 7, 2007.
  47. The figure "about one-half of one percent" takes into account the following (See, e.g., Leckie, Stephen (1999). "How Meat-centred Eating Patterns Affect Food Security and the Environment". For hunger-proof cities: sustainable urban food systems. Ottawa: International Development Research Centre. ISBN   978-0-88936-882-8. Archived from the original on |archive-url= requires |archive-date= (help)., which takes global average weight as 60 kg.), the total human biomass is the average weight multiplied by the current human population of approximately 6.5 billion (see, e.g., "World Population Information". U.S. Census Bureau. Retrieved September 28, 2006.[ permanent dead link ]): Assuming 60–70 kg to be the average human mass (approximately 130–150  lb on the average), an approximation of total global human mass of between 390 billion (390×109) and 455 billion kg (between 845 billion and 975 billion lb, or about 423 million–488 million short tons). The total biomass of all kinds on earth is estimated to be in excess of 6.8 x 1013 kg (75 billion short tons). By these calculations, the portion of total biomass accounted for by humans would be very roughly 0.6%.
  48. Sengbusch, Peter V. "The Flow of Energy in Ecosystems – Productivity, Food Chain, and Trophic Level". Botany online. University of Hamburg Department of Biology. Archived from the original on August 21, 2011. Retrieved September 23, 2006.
  49. Pidwirny, Michael (2006). "Introduction to the Biosphere: Species Diversity and Biodiversity". Fundamentals of Physical Geography (2nd Edition). Archived from the original on August 21, 2011. Retrieved September 23, 2006.
  50. "How Many Species are There?". Extinction Web Page Class Notes. Archived from the original on September 9, 2006. Retrieved September 23, 2006.
  51. "Animal." World Book Encyclopedia. 16 vols. Chicago: World Book, 2003. This source gives an estimate of from 2 to 50 million.
  52. "Just How Many Species Are There, Anyway?". Science Daily. May 2003. Archived from the original on February 11, 2007. Retrieved September 26, 2006.
  53. Withers, Mark A.; et al. (1998). "Changing Patterns in the Number of Species in North American Floras". Land Use History of North America. Archived from the original on September 23, 2006. Retrieved September 26, 2006. Website based on the contents of the book: Sisk, T.D., ed. (1998). Perspectives on the land use history of North America: a context for understanding our changing environment (Revised September 1999 ed.). U.S. Geological Survey, Biological Resources Division. USGS/BRD/BSR-1998-0003.
  54. "Tropical Scientists Find Fewer Species Than Expected". Science Daily. April 2002. Archived from the original on August 30, 2006. Retrieved September 27, 2006.
  55. Bunker, Daniel E.; et al. (November 2005). "Species Loss and Aboveground Carbon Storage in a Tropical Forest". Science. 310 (5750): 1029–31. Bibcode:2005Sci...310.1029B. CiteSeerX   10.1.1.465.7559 . doi:10.1126/science.1117682. PMID   16239439.
  56. Wilcox, Bruce A. (2006). "Amphibian Decline: More Support for Biocomplexity as a Research Paradigm". EcoHealth. 3 (1): 1–2. doi:10.1007/s10393-005-0013-5.
  57. Clarke, Robin; Robert Lamb; Dilys Roe Ward, eds. (2002). "Decline and loss of species". Global environment outlook 3: past, present and future perspectives. London; Sterling, VA: Nairobi, Kenya: UNEP. ISBN   978-92-807-2087-7.
  58. "Why the Amazon Rainforest is So Rich in Species: News". Earthobservatory.nasa.gov. December 5, 2005. Archived from the original on February 25, 2011. Retrieved May 14, 2011.
  59. "Why The Amazon Rainforest Is So Rich in Species". Sciencedaily.com. December 5, 2005. Archived from the original on February 25, 2011. Retrieved May 14, 2011.
  60. Schopf, JW, Kudryavtsev, AB, Czaja, AD, and Tripathi, AB. (2007). Evidence of Archean life: Stromatolites and microfossils. Precambrian Research 158: 141–55.
  61. Schopf, JW (2006). "Fossil evidence of Archaean life". Philos Trans R Soc Lond B Biol Sci. 361 (1470): 869–85. doi:10.1098/rstb.2006.1834. PMC   1578735 . PMID   16754604.
  62. Peter Hamilton Raven; George Brooks Johnson (2002). Biology. McGraw-Hill Education. p. 68. ISBN   978-0-07-112261-0. Archived from the original on January 1, 2014. Retrieved July 7, 2013.
  63. 1 2 Line, M. (January 1, 2002). "The enigma of the origin of life and its timing". Microbiology. 148 (Pt 1): 21–27. doi:10.1099/00221287-148-1-21. PMID   11782495.
  64. "Photosynthesis more ancient than thought, and most living things could do it". phys.org. Archived from the original on January 20, 2019. Retrieved January 19, 2019.
  65. Berkner, L. V.; L. C. Marshall (May 1965). "On the Origin and Rise of Oxygen Concentration in the Earth's Atmosphere". Journal of the Atmospheric Sciences. 22 (3): 225–61. Bibcode:1965JAtS...22..225B. doi:10.1175/1520-0469(1965)022<0225:OTOARO>2.0.CO;2.
  66. Schopf J (1994). "Disparate rates, differing fates: tempo and mode of evolution changed from the Precambrian to the Phanerozoic". Proc Natl Acad Sci USA. 91 (15): 6735–42. Bibcode:1994PNAS...91.6735S. doi:10.1073/pnas.91.15.6735. PMC   44277 . PMID   8041691.
  67. Szewzyk U; Szewzyk R; Stenström T (1994). "Thermophilic, anaerobic bacteria isolated from a deep borehole in granite in Sweden". Proc Natl Acad Sci USA. 91 (5): 1810–13. Bibcode:1994PNAS...91.1810S. doi:10.1073/pnas.91.5.1810. PMC   43253 . PMID   11607462.
  68. Wolska K (2003). "Horizontal DNA transfer between bacteria in the environment". Acta Microbiol Pol. 52 (3): 233–43. PMID   14743976.
  69. Horneck G (1981). "Survival of microorganisms in space: a review". Adv Space Res. 1 (14): 39–48. doi:10.1016/0273-1177(81)90241-6. PMID   11541716.
  70. "flora". Merriam-Webster Online Dictionary. Merriam-Webster. Archived from the original on April 30, 2006. Retrieved September 27, 2006.
  71. "Glossary". Status and Trends of the Nation's Biological Resources. Reston, VA: Department of the Interior, Geological Survey. 1998. SuDocs No. I 19.202:ST 1/V.1-2. Archived from the original on July 15, 2007.
  72. "Feedback Loops in Global Climate Change Point to a Very Hot 21st Century". Science Daily. May 22, 2006. Archived from the original on December 8, 2006. Retrieved January 7, 2007.
  73. "Natural Resources contribution to GDP". World Development Indicators (WDI). November 2014. Archived from the original on December 23, 2014.
  74. "GDP – Composition by Sector". The World Factbook . Central Intelligence Agency. Archived from the original on May 22, 2014. Retrieved February 19, 2017.
  75. "Plant Conservation Alliance – Medicinal Plant Working Groups Green Medicine". US National Park Services. Archived from the original on October 9, 2006. Retrieved September 23, 2006.
  76. Oosthoek, Jan (1999). "Environmental History: Between Science & Philosophy". Environmental History Resources. Archived from the original on June 26, 2007. Retrieved December 1, 2006.
  77. "On the Beauty of Nature". The Wilderness Society. Archived from the original on September 9, 2006. Retrieved September 29, 2006.
  78. History of Conservation Archived July 8, 2006, at the Wayback Machine BC Spaces for Nature. Accessed: May 20, 2006.
  79. Rothenberg, David (2011). Survival of the Beautiful: Art, Science and Evolution. Bloomsbury. ISBN   978-1-60819-216-8.
  80. Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; et al. (Planck Collaboration) (March 22, 2013). "Planck 2013 results. I. Overview of products and scientific results – Table 9". Astronomy and Astrophysics . 571: A1. arXiv: 1303.5062 . Bibcode:2014A&A...571A...1P. doi:10.1051/0004-6361/201321529.
  81. Taylor, Barry N. (1971). "Introduction to the constants for nonexperts". National Institute of Standards and Technology. Archived from the original on January 7, 2007. Retrieved January 7, 2007.
  82. Varshalovich, D.A.; Potekhin, A.Y. & Ivanchik, A.V. (2000). "Testing cosmological variability of fundamental constants". AIP Conference Proceedings. 506: 503. arXiv: physics/0004062 . Bibcode:2000AIPC..506..503V. CiteSeerX   10.1.1.43.6877 . doi:10.1063/1.1302777.
  83. Bibring, J; et al. (2006). "Global mineralogical and aqueous mars history derived from OMEGA/Mars Express data". Science. 312 (5772): 400–04. Bibcode:2006Sci...312..400B. doi:10.1126/science.1122659. PMID   16627738.
  84. Malik, Tariq (March 8, 2005). "Hunt for Mars life should go underground". Space.com via msnbc.msn.com. Archived from the original on November 16, 2006. Retrieved September 4, 2006.
  85. Turner, Scott (March 2, 1998). "Detailed Images From Europa Point To Slush Below Surface". NASA. Archived from the original on September 29, 2006. Retrieved September 28, 2006.
  86. Choi, Charles Q. (March 21, 2011) New Estimate for Alien Earths: 2 Billion in Our Galaxy Alone | Alien Planets, Extraterrestrial Life & Extrasolar Planets | Exoplanets & Kepler Space Telescope Archived July 3, 2013, at the Wayback Machine . Space.com.
  87. Papineau, David, "Naturalism", The Stanford Encyclopedia of Philosophy (Winter 2016 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/win2016/entries/naturalism/ Archived April 1, 2019, at the Wayback Machine >

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An extinction event is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the rate of speciation. Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from the threshold chosen for describing an extinction event as "major", and the data chosen to measure past diversity.

Biodiversity Variety and variability of life forms

Biodiversity refers to the variety and variability of life on Earth. Biodiversity is typically a measure of variation at the genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near the equator, which is the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species. Marine biodiversity is usually highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future.

Climate change Change in the statistical distribution of weather patterns for an extended period

Climate change occurs when changes in Earth's climate system result in new weather patterns that last for at least a few decades, and maybe for millions of years. The climate system is comprised of five interacting parts, the atmosphere (air), hydrosphere (water), cryosphere, biosphere, and lithosphere. The climate system receives nearly all of its energy from the sun, with a relatively tiny amount from earth's interior. The climate system also gives off energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth's energy budget. When the incoming energy is greater than the outgoing energy, earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.

Paleoclimatology is the study of changes in climate taken on the scale of the entire history of Earth. It uses a variety of proxy methods from the Earth and life sciences to obtain data previously preserved within things such as rocks, sediments, ice sheets, tree rings, corals, shells, and microfossils. It then uses the records to determine the past states of the Earth's various climate regions and its atmospheric system. Studies of past changes in the environment and biodiversity often reflect on the current situation, specifically the impact of climate on mass extinctions and biotic recovery.

Conservation biology the study of threats to biological diversity

Conservation biology is the management of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management.

This glossary of ecology is a list of definitions of terms and topics in ecology and related fields. For more specific definitions from other glossaries related to ecology, see Glossary of biology and Glossary of environmental science.

Habitat conservation

Habitat conservation is a management practice that seeks to conserve, protect and restore habitats and prevent species extinction, fragmentation or reduction in range. It is a priority of many groups that cannot be easily characterized in terms of any one ideology.

Habitat ecological or environmental area inhabited by a particular species; natural environment in which an organism lives, or the physical environment that surrounds a species population

In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both physical and biological features. A species' habitat is those places where it can find food, shelter, protection and mates for reproduction.

Human impact on the environment human impacts on environment

Human impact on the environment or anthropogenic impact on the environment includes changes to biophysical environments and ecosystems, biodiversity, and natural resources caused directly or indirectly by humans, including global warming, environmental degradation, mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Modifying the environment to fit the needs of society is causing severe effects, which become worse as the problem of human overpopulation continues. Some human activities that cause damage to the environment on a global scale include human reproduction, overconsumption, overexploitation, pollution, and deforestation, to name but a few. Some of the problems, including global warming and biodiversity loss pose an existential risk to the human race, and overpopulation causes those problems.

Marine life The plants, animals and other organisms that live in the salt water of the sea or ocean, or the brackish water of coastal estuaries

Marine life, or sea life or ocean life, is the plants, animals and other organisms that live in the salt water of the sea or ocean, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms produce oxygen. Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land.

A runaway greenhouse effect is a state in which a net positive feedback between surface temperature and atmospheric opacity increases the strength of the greenhouse effect on a planet until its oceans boil away.An example of this is believed to have happened in the early history of Venus. On the Earth the IPCC states that "a 'runaway greenhouse effect'—analogous to [that of] Venus—appears to have virtually no chance of being induced by anthropogenic activities."

Wild fisheries

A fishery is an area with an associated fish or aquatic population which is harvested for its commercial value. Fisheries can be marine (saltwater) or freshwater. They can also be wild or farmed.

Climate change and ecosystems

This article is about climate change and ecosystems. Future climate change is expected to affect particular ecosystems, including tundra, mangroves, coral reefs, and caves.

At the global scale sustainability and environmental management involves managing the oceans, freshwater systems, land and atmosphere, according to sustainability principles.

Land Solid surface of Earth that is not permanently covered by water.

Land, sometimes referred to as dry land, is the solid surface of Earth that is not permanently covered by water. The vast majority of human activity throughout history has occurred in land areas that support agriculture, habitat, and various natural resources. Some life forms have developed from predecessor species that lived in bodies of water.

<i>The Sixth Extinction: An Unnatural History</i> popular science book

The Sixth Extinction: An Unnatural History is a 2014 non-fiction book written by Elizabeth Kolbert and published by Henry Holt and Company. The book argues that the Earth is in the midst of a modern, man-made, sixth extinction. In the book, Kolbert chronicles previous mass extinction events, and compares them to the accelerated, widespread extinctions during our present time. She also describes specific species extinguished by humans, as well as the ecologies surrounding prehistoric and near-present extinction events. The author received the Pulitzer Prize for General Non-Fiction for the book in 2015.

David Beerling British scientist

David John Beerling is the Director of the Leverhulme Centre for Climate change mitigation and Sorby Professor of Natural Sciences in the Department of Animal and Plant Sciences (APS) at the University of Sheffield, UK.

Informally, a global issue is any issue that adversely affects the global community and environment, such as environmental issues, political crisis, social issues and economic crisis. Global issues range in severity from minor issues that affect everyone to global catastrophic risks that threaten the existence of the entire human race or its society.