Temperance is defined as moderation or voluntary self-restraint. It is described in terms of what an individual voluntarily refrains from doing; this includes restraint from retaliation in the form of non-violence and forgiveness, restraint from arrogance in the form of humility and modesty, restraint from excesses such as splurging now in the form of prudence, restraint from excessive anger or craving for something in the form of calmness and self-control. Temperance has been described as a virtue by religious thinkers and more psychologists in the positive psychology movement. In classical iconography, the virtue is depicted as a woman holding two vessels transferring water from one to another, it was one of the cardinal virtues in western thought found in Greek philosophy and Christianity, as well as eastern traditions such as Buddhism and Hinduism. Temperance is one of the six virtues in the positive psychology classification, included with wisdom, humanity and transcendence, it is characterized as the control over excess, expressed through characteristics such as chastity, humility, self-regulation, decorum, abstinence and mercy.
The term "temperance" can refer to the abstention from alcohol with reference to the temperance movement. The Greek definition of temperance translates to "moderation in thought, or feeling. Temperance is a major Athenian virtue. According to Aristotle, "temperance is a mean with regard to pleasures". In "Charmides", one of Plato's early dialogues, the one who possessed'sophrosune' is defined in four ways: one who has quietness, one who has modesty, one who does his own business, one who knows himself. Plato dismisses the three first definitions and argues against that if'sophrosune' would have been only the property of knowing what one knows or not it would be useless without knowledge about other matters. Themes of temperance can be seen across cultures and time. Temperance is an essential part of the Eightfold Path; the third and fifth of the five precepts reflect values of temperance: "misconduct concerning sense pleasures" and drunkenness are to be avoided. In the Judeo-Christian tradition, temperance is prolific.
The Old Testament emphasizes temperance as a core virtue, as evidenced in both Solomon's Book of Proverbs and in the Ten Commandments, with its admonitions against adultery and covetousness. The New Testament does so as well, with forgiveness being central to theology and self-control being one of the Fruits of the Spirit. With regard to Christian theology, the word temperance is used by the King James Version in Galatians 5:23 for the Greek word ἐγκρατεία, which means self-control or discipline. Thomas Aquinas promoted Plato's original virtues in addition to several others. Within the Christian church Temperance is a virtue akin to self-control, it is applied to all areas of life. It can be viewed in practice among sects like the Amish, Old Order Mennonites, Conservative Mennonites. In the Christian religion, temperance is a virtue that moderates attraction and desire for pleasure and "provides balance in the use of created goods". St. Thomas calls it a "disposition of the mind which binds the passions".
Temperance is believed to combat the sin of gluttony. Temperance is broken down into four main strengths: forgiveness, humility and self-regulation; the concept of dama in Hinduism is equivalent to temperance. It is sometimes written as damah; the word dama, Sanskrit derivative words based on it, connote the concepts of self-control and self-restraint. Brihadaranyaka Upanishad, in verse 5.2.3, states that three characteristics of a good, developed person are self-restraint and love for all sentient life, charity. In Hinduism literature dedicated to yoga, self-restraint is expounded with the concept of yamas. According to ṣaṭsampad, self-restraint is one of the six cardinal virtues; the list of virtues that constitute a moral life evolve in upanishads. Over time, new virtues were conceptualized and added, some replaced. For example, Manusamhita listed ten virtues necessary for a human being to live a dharmic life: Dhriti, Dama, Saucha, Indriyani-graha, vidya, akrodha. In verses this list was reduced to five virtues by the same scholar, by merging and creating a more broader concept.
The shorter list of virtues became: Ahimsa, Asteya, Satyam. This trend of evolving concepts continue in classical Sanskrit literature, Dama with Ahimsa and few other virtues present in the evolving list of virtues necessary for a moral life. Five types of self-restraints are considered essential for a moral and ethical life in Hindu philosophy: one must refrain from any violence that causes injury to others, refrain from starting or propagating deceit and falsehood, refrain from theft of other's property, refrain from sexually cheating on one's partner, refrain from avarice; the scope of self-restraint includes one's action, the words one speaks or writes, in one's though
Animal welfare is the well-being of nonhuman animals. The standards of "good" animal welfare vary between different contexts; these standards are under constant review and are debated and revised by animal welfare groups and academics worldwide. Animal welfare science uses various measures, such as longevity, immunosuppression, behavior and reproduction, although there is debate about which of these indicators provide the best information. Respect for animal welfare is based on the belief that nonhuman animals are sentient and that consideration should be given to their well-being or suffering when they are under the care of humans; these concerns can include how animals are slaughtered for food, how they are used in scientific research, how they are kept, how human activities affect the welfare and survival of wild species. There are two forms of criticism of the concept of animal welfare, coming from diametrically opposite positions. One view, held by some thinkers in history, holds; the other view is based on the animal rights position that animals should not be regarded as property and any use of animals by humans is unacceptable.
Accordingly, some animal rights proponents argue that the perception of better animal welfare facilitates continued and increased exploitation of animals. Some authorities therefore treat animal animal rights as two opposing positions. Others see animal welfare gains as incremental steps towards animal rights; the predominant view of modern neuroscientists, notwithstanding philosophical problems with the definition of consciousness in humans, is that consciousness exists in nonhuman animals. However, some still maintain that consciousness is a philosophical question that may never be scientifically resolved. Early legislation in the Western world on behalf of animals includes the Ireland Parliament "An Act against Plowing by the Tayle, pulling the Wooll off living Sheep", 1635, the Massachusetts Colony "Off the Bruite Creatures" Liberty 92 and 93 in the "Massachusetts Body of Liberties" of 1641. Since 1822, when Irish MP Richard Martin brought the "Cruel Treatment of Cattle Act 1822" through Parliament offering protection from cruelty to cattle and sheep, an animal welfare movement has been active in England.
Martin was among the founders of the world's first animal welfare organization, the Society for the Prevention of Cruelty to Animals, or SPCA, in 1824. In 1840, Queen Victoria gave the society her blessing, it became the RSPCA; the society used members' donations to employ a growing network of inspectors, whose job was to identify abusers, gather evidence, report them to the authorities. In 1837, the German minister Albert Knapp founded the first German animal welfare society. One of the first national laws to protect animals was the UK "Cruelty to Animals Act 1835" followed by the "Protection of Animals Act 1911". In the US it was many years until there was a national law to protect animals—the "Animal Welfare Act of 1966"—although there were a number of states that passed anti-cruelty laws between 1828 and 1898. In India, animals are protected by the "Prevention of Cruelty to Animals Act, 1960". Significant progress in animal welfare did not take place until the late 20th century. In 1965, the UK government commissioned an investigation—led by Professor Roger Brambell—into the welfare of intensively farmed animals in response to concerns raised in Ruth Harrison's 1964 book, Animal Machines.
On the basis of Professor Brambell's report, the UK government set up the Farm Animal Welfare Advisory Committee in 1967, which became the Farm Animal Welfare Council in 1979. The committee's first guidelines recommended that animals require the freedoms to "stand up, lie down, turn around, groom themselves and stretch their limbs." The guidelines have since been elaborated upon to become known as the Five Freedoms. In the UK, the "Animal Welfare Act 2006" consolidated many different forms of animal welfare legislation. A number of animal welfare organisations are campaigning to achieve a Universal Declaration on Animal Welfare at the United Nations. In principle, the Universal Declaration would call on the United Nations to recognise animals as sentient beings, capable of experiencing pain and suffering, to recognise that animal welfare is an issue of importance as part of the social development of nations worldwide; the campaign to achieve the UDAW is being co-ordinated by World Animal Protection, with a core working group including Compassion in World Farming, the RSPCA, the Humane Society International.
Animal welfare science is an emerging field that seeks to answer questions raised by the keeping and use of animals, such as whether hens are frustrated when confined in cages, whether the psychological well-being of animals in laboratories can be maintained, whether zoo animals are stressed by the transport required for international conservation. Animal testing Abandoned pets Behavioral enrichment Blood sport Cruelty to animals Feral cat Hunting Overpopulation in companion animals Overview of discretionary invasive procedures on animals Poaching Puppy mills Whaling A major concern for the welfare of farm animals is factory farming in which large numbers of animals are reared in confinement at high stocking densities. Issues include the limited opportunities for natural behaviors, for example, in battery cages and gestation crates, instead producing abnormal behaviors such as tail-biting and feather pecking, routine invasive procedures such as beak trimming and ear notching. More extensive methods of farming, e.g. free
Portland is the largest and most populous city in the U. S. state of Oregon and the seat of Multnomah County. It is a major port in the Willamette Valley region of the Pacific Northwest, at the confluence of the Willamette and Columbia rivers; as of 2017, Portland had an estimated population of 647,805, making it the 26th-largest city in the United States, the second-most populous in the Pacific Northwest. 2.4 million people live in the Portland metropolitan statistical area, making it the 25th most populous MSA in the United States. Its Combined Statistical Area ranks 18th-largest with a population of around 3.2 million. 60% of Oregon's population resides within the Portland metropolitan area. Named after Portland, the Oregon settlement began to be populated in the 1830s near the end of the Oregon Trail, its water access provided convenient transportation of goods, the timber industry was a major force in the city's early economy. At the turn of the 20th century, the city had a reputation as one of the most dangerous port cities in the world, a hub for organized crime and racketeering.
After the city's economy experienced an industrial boom during World War II, its hard-edged reputation began to dissipate. Beginning in the 1960s, Portland became noted for its growing progressive political values, earning it a reputation as a bastion of counterculture; the city operates with a commission-based government guided by a mayor and four commissioners as well as Metro, the only directly elected metropolitan planning organization in the United States. The city government is notable for its land-use investment in public transportation. Portland is recognized as one of the world's most environmentally conscious cities because of its high walkability, large community of bicyclists, farm-to-table dining, expansive network of public transportation options, over 10,000 acres of public parks, its climate is marked by cool, rainy winters. This climate is ideal for growing roses, Portland has been called the "City of Roses" for over a century. During the prehistoric period, the land that would become Portland was flooded after the collapse of glacial dams from Lake Missoula, in what would become Montana.
These massive floods occurred during the last ice age and filled the Willamette Valley with 300 to 400 feet of water. Before American pioneers began arriving in the 1800s, the land was inhabited for many centuries by two bands of indigenous Chinook people—the Multnomah and the Clackamas; the Chinook people occupying the land were first documented in 1805 by Meriwether Lewis and William Clark. Before its European settlement, the Portland Basin of the lower Columbia River and Willamette River valleys had been one of the most densely populated regions on the Pacific Coast. Large numbers of pioneer settlers began arriving in the Willamette Valley in the 1830s via the Oregon Trail, though life was centered in nearby Oregon City. In the early 1840s a new settlement emerged ten miles from the mouth of the Willamette River halfway between Oregon City and Fort Vancouver; this community was referred to as "Stumptown" and "The Clearing" because of the many trees cut down to allow for its growth. In 1843 William Overton saw potential in the new settlement but lacked the funds to file an official land claim.
For 25 cents, Overton agreed to share half of the 640-acre site with Asa Lovejoy of Boston. In 1845 Overton sold his remaining half of the claim to Francis W. Pettygrove of Maine. Both Pettygrove and Lovejoy wished to rename "The Clearing" after their respective hometowns; this controversy was settled with a coin toss that Pettygrove won in a series of two out of three tosses, thereby providing Portland with its namesake. The coin used for this decision, now known as the Portland Penny, is on display in the headquarters of the Oregon Historical Society. At the time of its incorporation on February 8, 1851, Portland had over 800 inhabitants, a steam sawmill, a log cabin hotel, a newspaper, the Weekly Oregonian. A major fire swept through downtown in August 1873, destroying twenty blocks on the west side of the Willamette along Yamhill and Morrison Streets, causing $1.3 million in damage. By 1879, the population had grown to 17,500 and by 1890 it had grown to 46,385. In 1888, the city built the first steel bridge built on the West Coast.
Portland's access to the Pacific Ocean via the Willamette and Columbia rivers, as well as its easy access to the agricultural Tualatin Valley via the "Great Plank Road", provided the pioneer city with an advantage over other nearby ports, it grew quickly. Portland remained the major port in the Pacific Northwest for much of the 19th century, until the 1890s, when Seattle's deepwater harbor was connected to the rest of the mainland by rail, affording an inland route without the treacherous navigation of the Columbia River; the city had its own Japantown, for one, the lumber industry became a prominent economic presence, due to the area's large population of Douglas Firs, Western Hemlocks, Red Cedars, Big Leaf Maple trees. Portland developed a reputation early in its history as a gritty port town; some historians have described the city's early establishment as being a "scion of New England. In 1889, The Oregonian called Portland "the most filthy city in the Northern States", due to the unsanitary sewers and gutters, and, at the turn of the 20th century, it was considered one of the most dangerous port cities in the world.
The city housed a large number of saloons
A fountain is a piece of architecture which pours water into a basin or jets it into the air to supply drinking water and/or for a decorative or dramatic effect. Fountains were purely functional, connected to springs or aqueducts and used to provide drinking water and water for bathing and washing to the residents of cities and villages; until the late 19th century most fountains operated by gravity, needed a source of water higher than the fountain, such as a reservoir or aqueduct, to make the water flow or jet into the air. In addition to providing drinking water, fountains were used for decoration and to celebrate their builders. Roman fountains were decorated with stone masks of animals or heroes. In the Middle Ages and Muslim garden designers used fountains to create miniature versions of the gardens of paradise. King Louis XIV of France used fountains in the Gardens of Versailles to illustrate his power over nature; the baroque decorative fountains of Rome in the 17th and 18th centuries marked the arrival point of restored Roman aqueducts and glorified the Popes who built them.
By the end of the 19th century, as indoor plumbing became the main source of drinking water, urban fountains became purely decorative. Mechanical pumps replaced gravity and allowed fountains to recycle water and to force it high into the air; the Jet d'Eau in Lake Geneva, built in 1951, shoots water 140 metres in the air. The highest such fountain in the world is King Fahd's Fountain in Jeddah, Saudi Arabia, which spouts water 260 metres above the Red Sea. Fountains are used today to decorate city squares. A Splash pad or spray pool allows city residents to get wet and cool off in summer; the musical fountain combines moving jets of water, colored lights and recorded music, controlled by a computer, for dramatic effects. Fountains can themselves be musical instruments played by obstruction of one or more of their water jets. Drinking fountains provide clean drinking water in public buildings and public spaces. Ancient civilizations built stone basins to hold precious drinking water. A carved stone basin, dating to around 2000 BC, was discovered in the ruins of the ancient Sumerian city of Lagash in modern Iraq.
The ancient Assyrians constructed a series of basins in the gorge of the Comel River, carved in solid rock, connected by small channels, descending to a stream. The lowest basin was decorated with carved reliefs of two lions; the ancient Egyptians had ingenious systems for hoisting water up from the Nile for drinking and irrigation, but without a higher source of water it was not possible to make water flow by gravity, no Egyptian fountains or pictures of fountains have been found. The ancient Greeks used gravity-powered fountains to distribute water. According to ancient historians, fountains existed in Athens and other ancient Greek cities in the 6th century BC as the terminating points of aqueducts which brought water from springs and rivers into the cities. In the 6th century BC, the Athenian ruler Peisistratos built the main fountain of Athens, the Enneacrounos, in the Agora, or main square, it had spouts, which supplied drinking water to local residents. Greek fountains were made of stone or marble, with water flowing through bronze pipes and emerging from the mouth of a sculpted mask that represented the head of a lion or the muzzle of an animal.
Most Greek fountains flowed by simple gravity, but they discovered how to use principle of a siphon to make water spout, as seen in pictures on Greek vases. The Ancient Romans built an extensive system of aqueducts from mountain rivers and lakes to provide water for the fountains and baths of Rome; the Roman engineers used lead pipes instead of bronze to distribute the water throughout the city. The excavations at Pompeii, which revealed the city as it was when it was destroyed by Mount Vesuvius in 79 AD, uncovered free-standing fountains and basins placed at intervals along city streets, fed by siphoning water upwards from lead pipes under the street; the excavations of Pompeii showed that the homes of wealthy Romans had a small fountain in the atrium, or interior courtyard, with water coming from the city water supply and spouting into a small bowl or basin. Ancient Rome was a city of fountains. According to Sextus Julius Frontinus, the Roman consul, named curator aquarum or guardian of the water of Rome in 98 AD, Rome had nine aqueducts which fed 39 monumental fountains and 591 public basins, not counting the water supplied to the Imperial household and owners of private villas.
Each of the major fountains was connected to two different aqueducts, in case one was shut down for service. The Romans were able to make fountains jet water into the air, by using the pressure of water flowing from a distant and higher source of water to create hydraulic head, or force. Illustrations of fountains in gardens spouting water are found on wall paintings in Rome from the 1st century BC, in the villas of Pompeii; the Villa of Hadrian in Tivoli featured a large swimming basin with jets of water. Pliny the Younger described the banquet room of a Roman villa where a fountain began to jet water when visitors sat on a marble seat; the water flowed into a basin, where the courses of a banquet were served in floating dishes shaped like boats. Roman engineers built fountains throughout the Roman Empire. Examples can be found today in the ruins of Roman towns in Vaison-la-Romaine and Glanum in France, in Augst and other sites. During the Middle Ages, Roman aqueducts were wrecked or fell into decay, many fountains throughout Europ
A pub, or public house, is an establishment licensed to sell alcoholic drinks, which traditionally include beer and cider. It is a relaxed, social drinking establishment and a prominent part of British, Breton, New Zealand, South African and Australian cultures. In many places in villages, a pub is the focal point of the community. In his 17th-century diary Samuel Pepys described the pub as "the heart of England". Pubs can be traced back to Roman taverns, through the Anglo-Saxon alehouse to the development of the tied house system in the 19th century. In 1393, King Richard II of England introduced legislation that pubs had to display a sign outdoors to make them visible for passing ale tasters, who would assess the quality of ale sold. Most pubs focus on offering beers and similar drinks; as well, pubs sell wines and soft drinks and snacks. The owner, tenant or manager is known as the pub landlord or landlady, or publican. Referred to as their "local" by regulars, pubs are chosen for their proximity to home or work, the availability of a particular beer or ale or a good selection, good food, a social atmosphere, the presence of friends and acquaintances, the availability of recreational activities such as a darts team, a skittles team, a pool or snooker table.
The pub quiz was established in the UK in the 1970s. The inhabitants of the British Isles have been drinking ale since the Bronze Age, but it was with the arrival of the Roman Empire on its shores in the 1st century, the construction of the Roman road networks that the first inns, called tabernae, in which travellers could obtain refreshment, began to appear. After the departure of Roman authority in the 5th century and the fall of the Romano-British kingdoms, the Anglo-Saxons established alehouses that grew out of domestic dwellings; the Anglo-Saxon alewife would put a green bush up on a pole to let. These alehouses evolved into meeting houses for the folk to congregate and arrange mutual help within their communities. Herein lies "pub" as it is colloquially called in England, they spread across the kingdom, becoming so commonplace that in 965 King Edgar decreed that there should be no more than one alehouse per village. A traveller in the early Middle Ages could obtain overnight accommodation in monasteries, but a demand for hostelries grew with the popularity of pilgrimages and travel.
The Hostellers of London were granted guild status in 1446 and in 1514 the guild became the Worshipful Company of Innholders. A survey in 1577 of drinking establishment in England and Wales for taxation purposes recorded 14,202 alehouses, 1,631 inns, 329 taverns, representing one pub for every 187 people. Inns are buildings where travellers can seek lodging and food and drink, they are located in the country or along a highway. In Europe, they first sprang up when the Romans built a system of roads two millennia ago; some inns in Europe are several centuries old. In addition to providing for the needs of travellers, inns traditionally acted as community gathering places. In Europe, it is the provision of accommodation, if anything, that now distinguishes inns from taverns and pubs; the latter tend to provide alcohol, but less accommodation. Inns tend to be older and grander establishments: they provided not only food and lodging, but stabling and fodder for the traveller's horse and on some roads fresh horses for the mail coach.
Famous London inns include The George and The Tabard. There is, other kinds of establishment. Many pubs use "Inn" in their name, either because they are long established former coaching inns, or to summon up a particular kind of image, or in many cases as a pun on the word "in", as in "The Welcome Inn", the name of many pubs in Scotland; the original services of an inn are now available at other establishments, such as hotels and motels, which focus more on lodging customers than on other services, although they provide meals. In North America, the lodging aspect of the word "inn" lives on in hotel brand names like Holiday Inn, in some state laws that refer to lodging operators as innkeepers; the Inns of Court and Inns of Chancery in London started as ordinary inns where barristers met to do business, but became institutions of the legal profession in England and Wales. The 18th century saw a huge growth in the number of drinking establishments due to the introduction of gin. Brought to England by the Dutch after the Glorious Revolution of 1688, gin became popular after the government created a market for "cuckoo grain" or "cuckoo malt" by allowing unlicensed gin and beer production while imposing a heavy duty on all imported spirits.
As thousands of gin-shops sprang up all over England, brewers fought back by increasing the number of alehouses. By 1740 the production of gin had increased to six times that of beer and, because of its cheapness, it became popular with the poor, leading to the so-called Gin Craze. Over half of the 15,000 drinking establishments in London were gin shops; the drunkenness and lawlessness created by gin was seen to lead to the ruination and degradation of the working classes. The different effects of beer and gin were illustrated by William Hogarth in his engravings Beer Street and Gin Lane; the Gin Act 1736 imposed high taxes on retailers and led to riots in the streets
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. A few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, are present in most of its habitats. Bacteria inhabit soil, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Bacteria live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, only about half of the bacterial phyla have species that can be grown in the laboratory; the study of bacteria is known as a branch of microbiology. There are 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere.
The nutrient cycle includes the decomposition of dead bodies. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Data reported by researchers in October 2012 and published in March 2013 suggested that bacteria thrive in the Mariana Trench, with a depth of up to 11 kilometres, is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are."The famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. There are 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body.
This means that although they do have the upper hand in actual numbers, it is only by 30%, not 900%. The largest number exist in the gut flora, a large number on the skin; the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial in the gut flora. However several species of bacteria are pathogenic and cause infectious diseases, including cholera, anthrax and bubonic plague; the most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium and other metals in the mining sector, as well as in biotechnology, the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two different groups of organisms that evolved from an ancient common ancestor; these evolutionary domains are called Archaea. The word bacteria is the plural of the New Latin bacterium, the latinisation of the Greek βακτήριον, the diminutive of βακτηρία, meaning "staff, cane", because the first ones to be discovered were rod-shaped; the ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, bacteria and archaea were the dominant forms of life. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species.
However, gene sequences can be used to reconstruct the bacterial phylogeny, these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The most recent common ancestor of bacteria and archaea was a hyperthermophile that lived about 2.5 billion–3.2 billion years ago. Bacteria were involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves related to the Archaea; this involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya. Some eukaryotes that contained mitochondria engulfed cyanobacteria-like organisms, leading to the formation of chloroplasts in algae and plants; this is known as primary endosymbiosis. Bacteria display a wide diversity of sizes, called morphologies.
Bacterial cells are about one-tenth the size of eukaryotic cells