PRECIPITATION, STORMS AND OTHER WEATHER PHENOMENA; CLIMATE

History
The 'O' and 'P' class destroyers were the first of their kind built under the Emergency War Programme. They were born of the need for the Royal Navy to quickly replace many of its aging destroyers due to the clouds of war gathering in Europe. It was decided in an effort to cut costs and building time, that they would use the same machinery as the 'J' class, but with a simpler armament. These ships were designed for general fleet, patrol and escort duties. The 'O' class was ordered on September 3, 1939, with the HMS Oribi being the first completed in July 1941. Other ships were the Obdurate, Obedient, Offa, Onslaught, Onslow (leader), Opportune and Orwell. The similiar 'P' class was ordered on October 20, 1939, with the HMS Porcupine being finished in June 1941. The rest of the class was Pakenham (leader), Paladin, Panther, Partridge, Pathfinder, Penn and Petard.

All these ships served with distinction throughout the war. Their most famous action occurred in December 1942, while escorting convoy JW51B the Onslow, Obedient, Orwell, Obdurate, Oribi and the 'A' class destroyer Achates held off the Lutzow, Hipper and six KM destroyers for six hours. Finally HM cruisers Jamaica and Sheffield arrived and finally drove the Germans off, without loss. The Paladin, Oribi and Onslow were also responsible for individual U-boat kills, while the Pakenham and Petard shared one. The Pakenham, Panther and Porcupine were all lost while in the Mediterranean.

The Tamiya kit builds up to a fairly good representation of this class. However out of the box they can only be built as the two leaders, Onslow and Pakenham, modification of the aft gun house is required to do other members of the class. I relied heavily on Nat Richards' article from the IPMS Quarterly Review to make the changes in the kit that was necessary to make an accurate leader. The White Ensign Models O Class PE set was used to give them that much needed extra detail. To bring the kit up to a proper 1/700 scale, you need to lengthen the hull 1mm., however I chose not to do this, too scary! I scratch-built the RDF shacks, behind the bridge using plastic card, as they did not come with the kit. The splinter shields around the 4" HA gun were filed away and replaced them with PE fret. I am sure that if scaled out the originals would have been akin to Maginot Line fortifications.

HMS Pakenham

I chose to model the HMS Onslow with her lattice mast. This was added during her re-fit after the Barents Sea battle. I painted her in the Special home Fleet Destroyer Design white/G45/G20/B30. This scheme required a lot of masking due to its many sharp angle lines, but it certainly turns the kit into quite a stunning model. The Pakenham was done in a Western Approaches scheme WA blue/white. To the best of my knowledge she never carried this scheme, but I have always liked it, so there !!!

This kit does require a lot of work to make a decent model, but with the addition of the morePE set and the modifications per Nat Richards, it can be turned into a very good model.

Copyright © prowl2003

Strokkur geyser, Iceland

A geyser is a type of hot spring that erupts periodically, ejecting a column of hot water and steam into the air. The name geyser comes from Geysir, the name of an erupting spring at Haukadalur, Iceland; that name, in turn, comes from the Icelandic verb gjósa, “to gush”.

The formation of geysers requires a favourable hydrogeology which exists in only a few places on Earth, and so they are fairly rare phenomena. About 1,000 exist worldwide, with about half of these in Yellowstone National Park, U.S..^[1] Geyser eruptive activity may change or cease due to ongoing mineral deposition within the geyser plumbing, exchange of functions with nearby hot springs, earthquake influences, and human intervention.^[2]

Erupting fountains of liquefied nitrogen have been observed on Neptune's moon Triton, as have possible signs of carbon dioxide eruptions from Mars' south polar ice cap. These phenomena are also often referred to as geysers. Instead of being driven by geothermal energy, they seem to rely on solar heating aided by a kind of solid-state greenhouse effect. On Triton, the nitrogen may erupt to heights of 8 km.

[ Eruptions

1. Steam rises from heated water	2. Pulses of water swell upward
3. Surface is broken	4. Ejected water spouts upward and falls back

Geyser activity, like all hot spring activity, is caused by surface water gradually seeping down through the ground until it meets rock heated by magma. The geothermally heated water then rises back toward the surface by convection through porous and fractured rock. Geysers differ from noneruptive hot springs in their subterranean structure; many consist of a small vent at the surface connected to one or more narrow tubes that lead to underground reservoirs of water.

As the geyser fills, the water at the top of the column cools off, but because of the narrowness of the channel, convective cooling of the water in the reservoir is impossible. The cooler water above presses down on the hotter water beneath, not unlike the lid of a pressure cooker, allowing the water in the reservoir to become superheated, i.e. to remain liquid at temperatures well above the boiling point.

Ultimately, the temperatures near the bottom of the geyser rise to a point where boiling begins; steam bubbles rise to the top of the column. As they burst through the geyser's vent, some water overflows or splashes out, reducing the weight of the column and thus the pressure on the water underneath. With this release of pressure, the superheated water flashes into steam, boiling violently throughout the column. The resulting froth of expanding steam and hot water then sprays out of the geyser hole.

Eventually the water remaining in the geyser cools back to below the boiling point and the eruption ends; heated groundwater begins seeping back into the reservoir, and the whole cycle begins again. The duration of eruptions and time between successive eruptions vary greatly from geyser to geyser; Strokkur in Iceland erupts for a few seconds every few minutes, while Grand Geyser in the U.S. erupts for up to 10 minutes every 8–12 hours.

[ Types of geysers

Vixen Geyser in Yellowstone

There are two types of geysers: fountain geysers erupt from pools of water, typically in a series of intense, even violent, bursts; and cone geysers which erupt from cones or mounds of siliceous sinter (also known as geyserite), usually in steady jets that last anywhere from a few seconds to several minutes. Old Faithful, perhaps the best-known geyser at Yellowstone National Park, is an example of a cone geyser. Grand Geyser, the tallest predictable geyser on earth, also at Yellowstone National Park, is an example of a fountain geyser.

The intense transient forces inside erupting geysers are the main reason for their rarity. There are many volcanic areas in the world that have hot springs, mud pots and fumaroles, but very few with geysers. This is because in most places, even where other necessary conditions for geyser activity exist, the rock structure is loose, and eruptions will erode the channels and rapidly destroy any nascent geysers.

Most geysers form in places where there is volcanic rhyolite rock which dissolves in hot water and forms mineral deposits called siliceous sinter, or geyserite, along the inside of the plumbing systems. Over time these deposits cement the rock together tightly, strengthening the channel walls and enabling the geyser to persist.

Geysers are fragile phenomena and if conditions change, they can ‘die’. Many geysers have been destroyed by people throwing litter and debris into them; others have ceased to erupt due to dewatering by geothermal power plants. The Great Geysir of Iceland has had periods of activity and dormancy. During its long dormant periods, eruptions were sometimes humanly-induced — often on special occasions — by the addition of surfactants to the water. Inducing eruptions at Geysir is no longer done, as the forced eruptions were damaging the geyser's special plumbing system. Following an earthquake in Iceland in 2000 the geyser became somewhat more active again. Initially the geyser erupted about eight times a day. As of July 2003, Geysir erupts several times a week.

Hyperthermophiles produce some of the bright colors of Grand Prismatic Spring, Yellowstone National Park

[ Biology of geysers

Main article: Thermophile, Hyperthermophile.

The specific colours of geysers derive from the fact that despite the apparently harsh conditions, life is often found in them (and also in other hot habitats) in the form of thermophilic prokaryotes. No known eukaryote can survive over 60 °C (140 °F).

In the 1960s, when the research of biology of geysers first appeared, scientists were generally convinced that no life can survive above around 73 °C (163 °F)—the upper limit for the survival of cyanobacteria, as the structure of key cellular proteins and deoxyribonucleic acid (DNA) would be destroyed. The optimal temperature for thermophilic bacteria was placed even lower, around 55 °C (131 °F).^{[citation needed]}

However, the observations proved that it actually is possible for life to exist at high temperatures and that some bacteria prefer even temperatures higher than boiling point of water. Dozens of such bacteria are known nowadays.^{[citation needed]} Thermophiles prefer temperatures from 50 to 70 °C whilst hyperthermophiles grow better at temperatures as high as 80 to 110 °C. As they have heat-stable enzymes that retain their activity even at high temperatures, they have been used as a source of thermostable tools, that are important in medicine and biotechnology, for example in manufacturing antibiotics, plastics, detergents (by the use of heat-stable enzymes lipases, pullulanases and proteases), and fermentation products (for example ethanol is produced).^{[citation needed]} The fact that such bacteria exist also stretches our imagination about life on other celestial bodies, both inside and outside of solar system. Among these, the first discovered and the most important for biotechnology is Thermus aquaticus.^{[citation needed]}

 Numbers and distribution

Eruption of White Dome Geyser in Yellowstone

Geysers are quite rare, requiring a combination of water, heat, and fortuitous plumbing. The combination exists in few places on Earth. The five largest geyser fields in the world are:^[3]

1. Yellowstone National Park, Wyoming, United States, North America
2. Dolina Geiserov, Kamchatka Peninsula, Russia, Asia - partially destroyed by a mudslide on June 3, 2007.
3. El Tatio, Atacama Desert, Chile, South America
4. Taupo Volcanic Zone, North Island, New Zealand, Oceania
5. Iceland, Europe

There used to be two large geysers fields in Nevada — Beowawe and Steamboat Springs — but they were destroyed by the installation of nearby geothermal power plants. At the plants, geothermal drilling reduced the available heat and lowered the local water table to the point that geyser activity could no longer be sustained. There are more individual geysers around the world, in California, Peru, Bolivia, Mexico, Dominica, Azores, Kenya, Slovakia and Japan, but no other large clusters.

Yellowstone is the largest geyser locale, containing thousands of hot springs, and between three and five hundred geysers. Yellowstone includes the tallest active geyser (Steamboat Geyser in Norris Geyser Basin), as well as the renowned Old Faithful Geyser, Beehive Geyser, Giantess Geyser, Lion Geyser, Plume Geyser, Aurum Geyser, Castle Geyser, Sawmill Geyser, Grand Geyser, Oblong Geyser, Giant Geyser, Daisy Geyser, Grotto Geyser, Fan & Mortar Geysers, & Riverside Geyser, all in the Upper Geyser Basin.

Many of New Zealand’s geysers have been destroyed by humans in the last century. Several New Zealand geysers have also become dormant or extinct by natural means. The main remaining field is Whakarewarewa at Rotorua. Two thirds of the geysers at Orakei Korako were flooded by the Ohakuri hydroelectric dam in 1961. The Wairakei field was lost to a geothermal power plant in 1958. The Taupo Spa field was lost when the Waikato River level was deliberately altered in the 1950s. The Rotomahana field was destroyed by the Mount Tarawera eruption in 1886. Waimangu Geyser, which existed from 1900 to 1904, was the largest geyser ever known. It ceased to erupt after a landslide covered its crater. Small numbers of geysers still exist at other places within the Taupo Volcanic Zone including Ketetahi, Tokaanu and Wai-O-Tapu.

 Misnamed geysers

In a number of places where there is geothermal activity wells have been drilled and fitted with impermeable casements that allow them to erupt like geysers. Though these so-called artificial geysers, technically known as erupting geothermal wells, are not true geysers, they can be quite spectacular. Little Old Faithful Geyser, in Calistoga, California, is probably an erupting geothermal well.^{[citation needed]}

Sometimes drilled cold-water wells erupt in a geyser-like manner due to the build-up of pressure from dissolved carbon dioxide in the water. These are not true geysers either, but are often called cold-water geysers. The best known of these is probably Crystal Geyser, near Green River, Utah.^[4]

A perpetual spouter is a natural hot spring that spouts water constantly. Some of these are incorrectly called geysers, but because they are not periodic in nature they are not considered true geysers.

[edit] Geysers on Triton

Dark streaks deposited by geysers on Triton

One of the great surprises of the Voyager 2 flyby of Neptune in 1989 was the discovery of geysers on its moon, Triton. Astronomers noticed dark plumes rising to some 8 km above the surface, and depositing material up to 150 km downstream.

All the geysers observed were located between 40° and 60°S, the part of Triton's surface close to the subsolar point. This indicates that solar heating, although very weak at Triton's great distance from the Sun, probably plays a crucial role. It is thought that the surface of Triton probably consists of a semi-transparent layer of frozen nitrogen, which creates a kind of greenhouse effect, heating the frozen material beneath it until it breaks the surface in an eruption. A temperature increase of just 4 K above the ambient surface temperature of 38 K could drive eruptions to the heights observed.

Geothermal energy may also be important. Unusually for a major satellite, Triton orbits Neptune in a retrograde orbit—that is, in the opposite direction to Neptune's rotation. This generates tidal forces which are causing Triton's orbit to decay, so that in several billion years time it will reach its Roche limit [1] with Neptune. The tidal forces may also generate heat inside Triton, in the same way as Jupiter's gravity generates tidal forces on Io which drive its extreme volcanic activity.

Each eruption of a Triton geyser may last up to a year, and during this time about 0.1 km³ of material may be deposited downwind. Voyager's images of Triton's southern hemisphere show many streaks of dark material laid down by geyser activity.

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Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle

Biology (from Greek: βίος, bio, "life"; and λόγος, logos, "speech" lit. "to talk about life"), also referred to as the biological sciences, is the scientific study of life. Biology examines the structure, function, growth, origin, evolution, and distribution of living things. It classifies and describes organisms, their functions, how species come into existence, and the interactions they have with each other and with the natural environment. Four unifying principles form the foundation of modern biology: cell theory, evolution, genetics and homeostasis.

Biology as a separate science was developed in the nineteenth century, as scientists discovered that organisms shared fundamental characteristics. Biology is now a standard subject of instruction at schools and universities around the world, and over a million papers are published annually in a wide array of biology and medicine journals.^[1]

Most biological sciences are specialized disciplines. Traditionally, they are grouped by the type of organism being studied: botany, the study of plants; zoology, the study of animals; and microbiology, the study of microorganisms. The fields within biology are further divided based on the scale at which organisms are studied and the methods used to study them: biochemistry examines the fundamental chemistry of life; molecular biology studies the complex interactions of systems of biological molecules; cellular biology examines the basic building block of all life, the cell; physiology examines the physical and chemical functions of the tissues and organ systems of an organism; and ecology examines how various organisms and their environment interrelate.

[ Foundations of modern biology

• Cell theory. All living organisms are made of at least one cell, the basic unit of function in all organisms. In addition, the core mechanisms and chemistry of all cells in all organisms are similar, and cells emerge only from preexisting cells that multiply through cell division.

• Evolution. Through natural selection and genetic drift, a population's inherited traits change from generation to generation.

• Gene theory. A living organism's traits are encoded in their DNA, the fundamental component of genes. In addition, traits are passed on from one generation to the next by way of these genes. All information flows from genes to the phenotype, the observable physical or biochemical characteristics of the organism. Although the phenotype expressed by the gene may adapt to the environment of the organism, that information is not transferred back to the genes. Only through the process of evolution do genes change in response to the environment.

• Homeostasis. The physiological processes that allow an organism to maintain its internal environment notwithstanding its external environment.

 Cell theory

Main article: Cell theory

The cell is the fundamental unit of life. Cell theory states that all living things are composed of one or more cells, or the secreted products of those cells, for example, shell and bone. Cells arise from other cells through cell division, and in multicellular organisms, every cell in the organism's body is produced from a single cell in a fertilized egg. Furthermore, the cell is considered to be the basic part of the pathological processes of an organism.^[2]

 Evolution

Main article: Evolution

A central organizing concept in biology is that life changes and develops through evolution and that all lifeforms known have a common origin (see Common descent). This has led to the striking similarity of units and processes discussed in the previous section. Charles Darwin established evolution as a viable theory by articulating its driving force, natural selection (Alfred Russel Wallace is recognized as the co-discoverer of this concept). Darwin theorized that species and breeds developed through the processes of natural selection as well as by artificial selection or selective breeding^[3]. Genetic drift was embraced as an additional mechanism of evolutionary development in the modern synthesis of the theory.

The evolutionary history of the species— which describes the characteristics of the various species from which it descended— together with its genealogical relationship to every other species is called its phylogeny. Widely varied approaches to biology generate information about phylogeny. These include the comparisons of DNA sequences conducted within molecular biology or genomics, and comparisons of fossils or other records of ancient organisms in paleontology. Biologists organize and analyze evolutionary relationships through various methods, including phylogenetics, phenetics, and cladistics. For a summary of major events in the evolution of life as currently understood by biologists, see evolutionary timeline.

Up into the 19th century, it was commonly believed that life forms could appear spontaneously under certain conditions (see spontaneous generation). This misconception was challenged by William Harvey's diction that "all life [is] from [an] egg" (from the Latin "Omne vivum ex ovo"), a foundational concept of modern biology. It simply means that there is an unbroken continuity of life from its initial origin to the present time.

A group of organisms shares a common descent if they share a common ancestor. All organisms on the Earth both living and extinct have been or are descended from a common ancestor or an ancestral gene pool. This last universal common ancestor of all organisms is believed to have appeared about 3.5 billion years ago. Biologists generally regard the universality of the genetic code as definitive evidence in favor of the theory of universal common descent (UCD) for all bacteria, archaea, and eukaryotes (see: origin of life).

Evolution does not always give rise to progressively more complex organisms. For example, the process of dysgenics has been observed among the human population.^[4]

 Gene theoryhttp://prowl.blogfa.com/

Main article: Gene

Biological form and function are created from and passed on to the next generation by genes, which are the primary units of inheritance. Physiological adaption to an organism's environment cannot be coded into its genes and cannot be inherited by its offspring (see Lamarckism). Remarkably, widely different organisms, including bacteria, plants, animals, and fungi, all share the same basic machinery that copies and transcribes DNA into proteins. For example, bacteria with inserted human DNA will correctly yield the corresponding human protein.

The total complement of genes in an organism or cell is known as its genome which is stored on one or more chromosomes. A chromosome is a single, long DNA strand on which thousands of genes, depending on the organism, are encoded. When a gene is active, the DNA code is transcribed into an RNA copy of the gene's information. A ribosome then translates the RNA into a structural protein or catalytic protein.

 Homeostasis

Main article: Homeostasis

Homeostasis is the ability of an open system to regulate its internal environment to maintain a stable condition by means of multiple dynamic equilibrium adjustments controlled by interrelated regulation mechanisms. All living organisms, whether unicellular or multicellular, exhibit homeostasis. Homeostasis exists at the cellular level, for example cells maintain a stable internal acidity (pH); and at the level of the organism, for example warm-blooded animals maintain a constant internal body temperature. Homeostasis is a term that is also used in association with ecosystems, for example, the atmospheric concentration of carbon dioxide on Earth has been regulated by the concentration of plant life on Earth because plants remove more carbon dioxide from the atmosphere during the daylight hours than they emit to the atmosphere at night. Tissues and organs can also maintain homeostasis.

See also: Health.

 Research

Main article: List of biology disciplines

 Structural

Main articles: Molecular biology, Cell biology, Genetics, and Developmental biology

Molecular biology is the study of biology at a molecular level. This field overlaps with other areas of biology, particularly with genetics and biochemistry. Molecular biology chiefly concerns itself with understanding the interactions between the various systems of a cell, including the interrelationship of DNA, RNA, and protein synthesis and learning how these interactions are regulated.

Cell biology studies the physiological properties of cells, as well as their behaviors, interactions, and environment. This is done both on a microscopic and molecular level. Cell biology researches both single-celled organisms like bacteria and specialized cells in multicellular organisms like humans.

Understanding cell composition and how they function is fundamental to all of the biological sciences. Appreciating the similarities and differences between cell types is particularly important in the fields of cell and molecular biology. These fundamental similarities and differences provide a unifying theme, allowing the principles learned from studying one cell type to be extrapolated and generalized to other cell types.

Genetics is the science of genes, heredity, and the variation of organisms. Genes encode the information necessary for synthesizing proteins, which in turn play a large role in influencing (though, in many instances, not completely determining) the final phenotype of the organism. In modern research, genetics provides important tools in the investigation of the function of a particular gene, or the analysis of genetic interactions. Within organisms, genetic information generally is carried in chromosomes, where it is represented in the chemical structure of particular DNA molecules.

Developmental biology studies the process by which organisms grow and develop. Originating in embryology, modern developmental biology studies the genetic control of cell growth, differentiation, and "morphogenesis," which is the process that gives rise to tissues, organs, and anatomy. Model organisms for developmental biology include the round worm Caenorhabditis elegans, the fruit fly Drosophila melanogaster, the zebrafish Brachydanio rerio, the mouse Mus musculus, and the weed Arabidopsis thaliana.

Physiological

http://prowl.blogfa.com/

Main articles: Physiology and Anatomy

Physiology studies the mechanical, physical, and biochemical processes of living organisms by attempting to understand how all of the structures function as a whole. The theme of "structure to function" is central to biology. Physiological studies have traditionally been divided into plant physiology and animal physiology, but the principles of physiology are universal, no matter what particular organism is being studied. For example, what is learned about the physiology of yeast cells can also apply to human cells. The field of animal physiology extends the tools and methods of human physiology to non-human species. Plant physiology also borrows techniques from both fields.

Anatomy is an important branch of physiology and considers how organ systems in animals, such as the nervous, immune, endocrine, respiratory, and circulatory systems, function and interact. The study of these systems is shared with medically oriented disciplines such as neurology and immunology.

 Evolution

Main articles: Evolutionary biology, Evolution, Evolutionary synthesis, and Natural selection

Evolution is concerned with the origin and descent of species, as well as their change over time, and includes scientists from many taxonomically-oriented disciplines. For example, it generally involves scientists who have special training in particular organisms such as mammalogy, ornithology, botany, or herpetology, but use those organisms as systems to answer general questions about evolution. Evolutionary biology is mainly based on paleontology, which uses the fossil record to answer questions about the mode and tempo of evolution, as well as the developments in areas such as population genetics and evolutionary theory. In the 1980s, developmental biology re-entered evolutionary biology from its initial exclusion from the modern synthesis through the study of evolutionary developmental biology. Related fields which are often considered part of evolutionary biology are phylogenetics, systematics, and taxonomy.

Up into the 19th century, it was believed that life forms were being continuously created under certain conditions (see spontaneous generation). This misconception was challenged by William Harvey's diction that "all life [is] from [an] egg" (from the Latin "Omne vivum ex ovo"), a foundational concept of modern biology. It simply means that there is an unbroken continuity of life from its initial origin to the present time.

A group of organisms shares a common descent if they share a common ancestor. All organisms on the Earth have been and are descended from a common ancestor or an ancestral gene pool. This last universal common ancestor of all organisms is believed to have appeared about 3.5 billion years ago. Biologists generally regard the universality of the genetic code as definitive evidence in favor of the theory of universal common descent (UCD) for all bacteria, archaea, and eukaryotes (see: origin of life).

The two major traditional taxonomically-oriented disciplines are botany and zoology. Botany is the scientific study of plants. Botany covers a wide range of scientific disciplines that study the growth, reproduction, metabolism, development, diseases, and evolution of plant life. Zoology involves the study of animals, including the study of their physiology within the fields of anatomy and embryology. The common genetic and developmental mechanisms of animals and plants is studied in molecular biology, molecular genetics, and developmental biology. The ecology of animals is covered under behavioral ecology and other fields.^[5]

 Taxonomy

Main article: Taxonomy

Classification is the province of the disciplines of systematics and taxonomy. Taxonomy places organisms in groups called taxa, while systematics seeks to define their relationships with each other. This classification technique has evolved to reflect advances in cladistics and genetics, shifting the focus from physical similarities and shared characteristics to phylogenetics.

Traditionally, living things have been divided into five kingdoms:^{[6]http://prowl.blogfa.com/}

Monera -- Protista -- Fungi -- Plantae -- Animalia

However, many scientists now consider this five-kingdom system to be outdated. Modern alternative classification systems generally begin with the three-domain system:^[7]

Archaea (originally Archaebacteria) -- Bacteria (originally Eubacteria) -- Eukarya

These domains reflect whether the cells have nuclei or not, as well as differences in the cell exteriors.

Further, each kingdom is broken down continuously until each species is separately classified. The order is:

The scientific name of an organism is obtained from its genus and species. For example, humans would be listed as Homo sapiens. Homo would be the genus and sapiens is the species. Whenever writing the scientific name of an organism, it is proper to capitalize the first letter in the genus and put all of the species in lowercase; in addition the entire term would be put in italics or underlined. The term used for classification is called taxonomy.

There is also a series of intracellular parasites that are progressively "less alive" in terms of metabolic activity:

Viruses -- Viroids -- Prions

The dominant classification system is called Linnaean taxonomy, which includes ranks and binomial nomenclature. How organisms are named is governed by international agreements such as the International Code of Botanical Nomenclature (ICBN), the International Code of Zoological Nomenclature (ICZN), and the International Code of Nomenclature of Bacteria (ICNB). A fourth Draft BioCode was published in 1997 in an attempt to standardize naming in these three areas, but it has yet to be formally adopted. The Virus International Code of Virus Classification and Nomenclature (ICVCN) remains outside the BioCode.

 Environmental

Main articles: Ecology, Ethology, Behavior, and Biogeography

Ecology studies the distribution and abundance of living organisms, and the interactions between organisms and their environment. The environment of an organism includes both its habitat, which can be described as the sum of local abiotic factors such as climate and ecology, as well as the other the organisms that share its habitat. Ecological systems are studied at several different levels, from individuals and populations to ecosystems and the biosphere. As can be surmised, ecology is a science that draws on several disciplines.

Ethology studies animal behavior (particularly of social animals such as primates and canids), and is sometimes considered a branch of zoology. Ethologists have been particularly concerned with the evolution of behavior and the understanding of behavior in terms of the theory of natural selection. In one sense, the first modern ethologist was Charles Darwin, whose book "The Expression of the Emotions in Man and Animals" influenced many ethologists.

Biogeography studies the spatial distribution of organisms on the Earth, focusing on topics like plate tectonics, climate change, dispersal and migration, and cladistics.

Every living thing interacts with other organisms and its environment. One reason that biological systems can be difficult to study is that so many different interactions with other organisms and the environment are possible, even on the smallest of scales. A microscopic bacterium responding to a local sugar gradient is responding to its environment as much as a lion is responding to its environment when it searches for food in the African savannah. For any given species, behaviors can be co-operative, aggressive, parasitic or symbiotic. Matters become more complex when two or more different species interact in an ecosystem. Studies of this type are the province of ecology.

 History

Main articles: History of biology and History of medicine

Although the concept of biology as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to Galen and Aristotle in ancient Greece. During the Renaissance and early modern period, biological thought was revolutionized by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Vesalius and Harvey, who used experimentation and careful observation in physiology, and naturalists such as Linnaeus and Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms. Microscopy revealed the previously unknown world of microorganisms, laying the groundwork for cell theory. The growing importance of natural theology, partly a response to the rise of mechanical philosophy, encouraged the growth of natural history.^[8][9]

Over the 18th and 19th centuries, biological sciences such as botany and zoology became increasingly professional scientific disciplines. Lavoisier and other physical scientists began to connect the animate and inanimate worlds through physics and chemistry. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography—laying the foundations for biogeography, ecology and ethology. Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species. Cell theory provided a new perspective on the fundamental basis of life. These developments, as well as the results from embryology and paleontology, were synthesized in Charles Darwin's theory of evolution by natural selection. The end of the 19th century saw the fall of spontaneous generation and the rise of the germ theory of disease, though the mechanism of inheritance remained a mystery.^[5][10][8]

In the early 20th century, the rediscovery of Mendel's work led to the rapid development of genetics by Thomas Hunt Morgan and his students, and by the 1930s the combination of population genetics and natural selection in the "neo-Darwinian synthesis". New disciplines developed rapidly, especially after Watson and Crick proposed the structure of DNA. Following the establishment of the Central Dogma and the cracking of the genetic code, biology was largely split between organismal biology—the fields that deal with whole organisms and groups of organisms—and the fields related to cellular and molecular biology. By the late 20th century, new fields like genomics and proteomics were reversing this trend, with organismal biologists using molecular techniques, and molecular and cell biologists investigating the interplay between genes and the environment, as well as the genetics of natural populations of organisms.^{[11][12][13][14]}

 See also

• List of biology topics
• List of basic biology topics
• List of biologists

 References

 Further reading

• Alberts, Bruce; Johnson, A, Lewis, J, Raff, M, Roberts, K & Walter, P (2002). Molecular Biology of the Cell, 4th edition, Garland. ISBN 978-0815332183. 
• Begon, Michael; Townsend, CR & Harper, JL (2005). Ecology: From Individuals to Ecosystems, 4th edition, Blackwell Publishing Limited. ISBN 978-1405111171. 
• Campbell, Neil (2007). Biology, 7th edition, Benjamin-Cummings Publishing Company. ISBN 0-8053-7146-X. 
• Colinvaux, Paul (1979). Why Big Fierce Animals are Rare: An Ecologist's Perspective, reissue edition, Princeton University Press. ISBN 0691023646. 
• Hoagland, Mahlon (2007). The Way Life Works, reprint edition, Jones and Bartlett Publishers inc. ISBN 076371688X. 
• Janovy, John Jr. (2007). On Becoming a Biologist, 2nd edition, Bison Books. ISBN 0803276206. 
• Johnson, George B. (2007). Biology, Visualizing Life. Holt, Rinehart, and Winston. ISBN 0-03-016723-X.