MONA LISA by The Internal Expression
The Mona Lisa (Italian: Gioconda or Mona Lisa; French: Joconde is a half-length portrait painting by Italian artist Leonardo da Vinci.
The painting has been traditionally considered to depict the Italian noblewoman Lisa del Giocondo. It is painted in oil on a white poplar panel. Leonardo never gave the painting to the Giocondo family. It
was 
believed to have been painted between 1503 and 1506; however, Leonardo may have continued working on it as late as 1517. King Francis I of France acquired the Mona Lisa after Leonardo’s death in 1519, and it is now the property of the French Republic. It has normally been on display at the Louvre in Paris since 1797.
The Mona Lisa is one of the most valuable paintings in the world. It holds the Guinness World Record for the highest known painting insurance valuation in history at US$100 million in 1962, equivalent to $1 billion as of 2023.
Plastic surgery
Plastic surgery is a surgical specialty involving the restoration, reconstruction, or alteration of the human body. It can be divided into two main categories: reconstructive surgery and cosmetic surgery. Reconstructive surgery includes craniofacial surgery, hand surgery, microsurgery, and the treatment of burns. While reconstructive surgery aims to reconstruct a part of the body or improve its functioning, cosmetic (or aesthetic) surgery aims to improve the appearance of it.
All surgery has risks. Common complications of cosmetic surgery includes hematoma, nerve injury, infection, scarring, implant failure and end organ damage. Breast implants can have many complications, including rupture.
ALIENS by The Internal Expression
An artificial brain (or artificial mind) is software and hardware with cognitive abilities similar to those of the animal or human brain.
Research investigating “artificial brains” and brain emulation plays three important roles in science:
An ongoing attempt by neuroscientists to understand how the human brain works, known as cognitive neuroscience.
A thought experiment in the philosophy of artificial intelligence, demonstrating that it is possible, at least in theory, to create a machine that has all the capabilities of a human being.
A long-term project to create machines exhibiting behavior comparable to those of animals with complex central nervous system such as mammals and most particularly humans. The ultimate goal of creating a machine exhibiting human-like behavior or intelligence is sometimes called strong AI. Sources. From Artificial brain Wikipedia, the free encyclopedia
The Aliens (also known as a Xenomorph XX121, Internecivus raptus, or simply the alien or the creature) is an extraterrestrial species.
Extraterrestrial intelligence (ETI) refers to hypothetical intelligent extraterrestrial life. No such life has ever been observed to exist. The question of whether other inhabited worlds might exist has been debated since ancient times. The modern form of the concept emerged when the Copernican Revolution demonstrated that the Earth was a planet revolving around the Sun, and other planets were, conversely, other worlds. The question of whether other inhabited planets or moons exist was a natural consequence of this new understanding. It has become one of the most speculative questions in science and is a central theme of science fiction and popular culture. Sources. From Extraterrestrial intelligence Wikipedia, the free encyclopedia.
Highway of Enthusiasts by The Internal Expression
Highway is an historic term used in German-speaking countries for early, metalled, rural highways, designed by road engineers, as opposed to the hitherto, traditional, unpaved country roads. The term is no longer used in modern road construction in Western Europe, but survives in road names and is used by historians. In Eastern Europe and the post-Soviet states it remains a generic term for a common paved highway outside of built-up areas, but they may transition into prospekts within towns and cities. The German word Chaussee was borrowed from the French chaussée by the German construction industry in the 18th century. The French word, in turn, went back to the Gallo-Romanic via calciata and meant a road surfaced with firmly compacted crushed rock bound with lime. circular reference] Contemporary German translations of the word were Straßendamm (‘road embankment’) and Hochweg (‘high way’) and even the roughly similar English word, highway. Around 1790, Adelung complained that “several new authors have proposed German names” but these expressions “do not capture the concept either, and may be used for every other type of artificial way Kunststraße. The word Kunststraße (‘artificial road’) then established itself but, in the main, the French word entered the German language as a loanword.
The first roads of the chaussee type were built in Western Europe in the early 18th century, coming from Holland at the end of the baroque period. For example, in Swabia, the first road was built in the chaussee design between Öttingen and Nördlingen in 1753. After the Napoleonic Wars, during which the importance of well constructed roads became recognised – for military logistical and strategic reasons – not least because of the use made by the French of forced marches (up to then war strategy was based primarily on the garrison concept, i.e. the stationing of non-mobile troops), but also express mail services developed, thinking moved increasingly towards the concept of trunk roads (Fernstraßen), whose importance was based both on the comfort of individual road users and for reasons of national interest. In Prussia, for example, the construction of chaussees, especially after the Stein-Hardenberg reforms (1807) certainly served military purposes. This created a basis for improving the flow of trade during the early industrial period, even before the railway era began. The chaussee was also, important for urban development. With the advent of the chaussee, the concept was born of a major road running right to the gates of a town or city. And with the demolition of fortifications in the Gründerzeit period of the late 19th century, the avenue and boulevard appeared in the form of urban axes or ring roads as access roads to the chaussee. Sources. Chaussee (highway), from Wikipedia, the free encyclopedia
PASSION by The Internal Expression
Passion (Greek πάσχω “to suffer, to be acted on” and Late Latin (chiefly Christian) passio “passion; suffering” (from Latin pati “to suffer”; participle: passus)) is a term used to denote strong and intractable or barely controllable emotion or inclination with respect to a particular person or thing.
Passion can range from eager interest in, or admiration for, an idea, proposal, or cause; to enthusiastic enjoyment of an interest or activity; to strong attraction, excitement, or emotion towards a person. It is particularly used in the context of romance or sexual desire, though it generally implies a deeper or more encompassing emotion than that implied by the term lust, often incorporating ideas of ecstasy and/or suffering. Sources. Passion, from Wikipedia, the free encyclopedia
Tibetan Wanderer by The Internal Expression
10 striking facts about lightning
1. The speed of lightning
While the flashes we see as a result of a lightning strike travel at the speed of light (670,000,000 mph) an actual lightning strike travels at a comparatively gentle 270,000 mph. This means it would take about 55 minutes to travel to the moon, or around 1.5 seconds to get from London to Bristol.
2. A lightning bolt is 5 times hotter than the sun
By releasing a massive bolt of electricity, lightning is five times hotter than the sun when it strikes. But the average lightning strike lasts only 30 microseconds. The temperature of a lightning strike can reach 30,000K. Whereas the surface of the sun is just 6000K. This extreme temperature disparity highlights the incredible energy released during a lightning strike, which briefly outshines even the sun’s scorching surface temperature.
3. The most lightning-struck location in the world
Lake Maracaibo in Venezuela is the place on Earth that receives the most lightning strikes. Massive thunderstorms occur on 140-160 nights per year with an average of 28 lightning strikes per minute lasting up to 10 hours at a time. That’s as many as 40,000 lightning strikes in one night!
4. Thunder to lightning distance
You can use thunder as a gauge for how far away lightning is. This is because light travels at a staggering 186,282 miles per second. But sound travels much slower at about 1 mile every 5 seconds. So when you count the time it takes to hear thunder, counting to 5 means that it’s 1 mile away. If you count just one second, lightning is just 1056 feet away. This simple rule of thumb serves as a practical way for individuals to estimate the distance of a lightning strike and gauge their proximity to the impending storm.
5. 1,400,000,000 strikes every year
Lightning is one of nature’s most recurrent and common spectacles. Around the world, there are over 3,000,000 flashes every day. That’s around 44 strikes every second.
6. Lightning destroys trees
Trees can often be destroyed by lightning strikes. When lightning hits a tree, it usually travels just below the tree’s bark where there is a layer of sap and water. This layer becomes instantly heated and expands causing the bark to be blasted off the tree and sometimes splitting the wood.
7. But it can help plants grow
While nitrogen is in the air all around us, for plants to be able to absorb it (a process vital for their growth) they rely on a process called Nitrogen fixation. Although much of this process is done by bacteria and algae, the extreme heat of a lightning strike causes nitrogen to bond with oxygen to create nitrogen oxides which combine with moisture in the air to fall as rain and water plants with nitrate-rich water.
8. The width of a thumb and hotter than the sun
While the intensity of a lightning strike can make them appear as thick bolts across the sky, the actual width of a lightning bolt is only about 2-3 cm. The average length of a lightning bolt is about 2-3 miles. The charge carried down this small channel is so intense that the temperature of the lightning reaches 30,000 °C – that’s five times hotter than the surface of the Sun.
9. Volcanic lightning
While lightning storms are impressive in their own right, they don’t quite compare to the spectacle when volcanic eruptions trigger lightning strikes. When an eruption occurs, earth and ash are thrown into the air in a giant plume, colliding to create an electrical charge. In the same way as normal lightning, the imbalance between the plume’s electrical charge and the charge in the atmosphere leads to lightning strikes.
10. Counting lightning
To tell how far away a thunderstorm is, simply count the number of seconds between the flash of lightning and the boom of thunder that follows. Divide this number by five and this tells you how many miles away you are from the storm (or divide by three for the distance in kilometres).
And finally…
Did you know, until the late 18th century it was believed that ringing church bells repelled lightning so many church bells bore the inscription fulgura frango, meaning ‘I chase lightning’.
During a thunderstorm, bell ringers would run to the bell tower to ring the bells. However, a high tower with a metal bell was in fact about the worst place to be.
Between 1753 and 1786 in France, 103 bell-ringers were struck by lightning and killed, resulting in the custom being banned.
Sources. 10 Electrifying Lightning Facts: Get Thunderstruck from EarthHow, Learn Earth Science, 10 striking facts about lightning from an overview of the Met Office
LIKHOBORY by The Internal Expression
A sombrero (Spanish for ‘hat’, lit. ’shadower’; Spanish: [somˈbɾeɾo]) is a type of wide-brimmed Mexican men’s hat used to shield the face and eyes from the sun. It usually has a high, pointed crown; an extra-wide brim (broad enough to cast a shadow over the head, neck, and shoulders of the wearer) that is slightly upturned at the edge; and a chin strap to hold it in place.
In Mexico, this hat type is known as a sombrero de charro (“charro hat”, referring to the traditional Mexican horsemen). In Spanish, any wide-brimmed hat may be considered a sombrero.
Sombreros, like cowboy hats, were designed in response to the demands of the physical environment. The concept of a broad-brimmed hat worn by a rider on horseback can be seen as far back as the Mongolian horsemen of the 13th century, and in the Greek petasos two millennia before that. In hot, sunny climates hats often have evolved wide brims. The exact origin of the Mexican sombrero is unknown, but it is usually accepted that the hat originated with mestizo cowboys in Central Mexico. Although sombrero is usually taken to refer to the traditional Mexican headwear, the term sombrero predates this item of clothing, and has been applied to several differing styles of hat. Other types of hats known as sombrero can be found in South America and Spain, including the sombrero calañés, sombrero cordobés and sombrero de catite (Spain), and sombrero vueltiao (Colombia).
LIKHOBORY II by The Internal Expression
Many early Texan cowboys adopted the Spanish and Mexican sombrero with its flat crown and wide, flat brim. Also called the poblano, these hats came from Spain. The Mexican variation of the sombrero added an even wider brim and a high, conical crown. These are the hats worn by mariachi musicians and charros.
Both types of sombreros usually include a barboquejo or chin strap. In the Western United States, the sombrero had a high conical or cylindrical crown with a saucer-shaped brim, highly embroidered and made of plush felt. In the Philippines, due to the influence from Spain brought about by the Manila galleon trade, the term has been assimilated into the Tagalog language in the form of sumbrero and now refers to any hat – from Mexican sombreros (as used in the English language) to baseball caps. The galaxy Messier 104 is known as the Sombrero Galaxy due to its appearance. Similarly, Tampa Stadium was also known as “The Big Sombrero”.
Sources. Sombrero, from Wikipedia, the free encyclopedia
ARISTOCRAT by The Internal ExpressionI
Aristocracy (from Ancient Greek ἀριστοκρατίᾱ (aristokratíā) ‘rule of the best’; from ἄριστος (áristos) ‘best’, and κράτος (krátos) ‘power, strength’) is a form of government that places power in the hands of a small, privileged ruling class, the aristocrats. The term derives from the Greek αριστοκρατία (aristokratía), meaning ‘rule of the best’.
At the time of the word’s origins in ancient Greece, the Greeks conceived it as rule by the best-qualified citizens—and often contrasted it favorably with monarchy, rule by an individual. The term was first used by such ancient Greeks as Aristotle and Plato, who used it to describe a system where only the best of the citizens, chosen through a careful process of selection, would become rulers, and hereditary rule would actually have been forbidden, unless the rulers’ children performed best and were better endowed with the attributes that make a person fit to rule compared with every other citizen in the polity.
Hereditary rule in this understanding is more related to oligarchy, a corrupted form of aristocracy where there is rule by a few, but not by the best. Plato, Socrates, Aristotle, Xenophon, and the Spartans considered aristocracy (the ideal form of rule by the few) to be inherently better than the ideal form of rule by the many (politeia), but they also considered the corrupted form of aristocracy (oligarchy) to be worse than the corrupted form of democracy (mob rule). This belief was rooted in the assumption that the masses could only produce average policy, while the best of men could produce the best policy, if they were indeed the best of men. Later Polybius in his analysis of the Roman Constitution used the concept of aristocracy to describe his conception of a republic as a mixed form of government, along with democracy and monarchy in their conception from then, as a system of checks and balances, where each element checks the excesses of the other.
In modern times, aristocracy was usually seen as rule by a privileged group, the aristocratic class, and has since been contrasted with democracy.
The concept evolved in ancient Greece in which a council of leading citizens was commonly empowered. That was contrasted with representative democracy in which a council of citizens was appointed as the “senate” of a city state or other political unit. The Greeks did not like the concept of monarchy, and as their democratic system fell, aristocracy was upheld.
The concept of aristocracy according to Plato has an ideal state ruled by the philosopher king. Plato describes “philosopher kings” as “those who love the sight of truth” (Republic 475c) and supports the idea with the analogy of a captain and his ship or a doctor and his medicine. According to him, sailing and health are not things that everyone is qualified to practice by nature. A large part of the Republic then addresses how the educational system should be set up to produce philosopher kings.
In contrast to its original conceptual drawing by Aristotle in classical antiquity, aristocracy is not in modern times understood in opposition to oligarchy or strictly as a form of government, with entitled nobility as in monarchies or aristocratic merchant republics. Its original classical understanding has been taken up by the modern concepts that can be loosely equivalent to meritocracy or technocracy.
Aristocracies dominated political and economic power for most of the medieval and modern periods almost everywhere in Europe, using their wealth and land ownership to form a powerful political force. The English Civil War involved the first sustained organised effort to reduce aristocratic power in Europe.
In the 18th century, the rising merchant class attempted to use money to buy into the aristocracy, with some success. However, the French Revolution in the 1790s forced many French aristocrats into exile and caused consternation and shock in the aristocratic families of neighbouring countries. After the defeat of Napoleon in 1814, some of the surviving exiles returned, but their position within French society was not recovered.
Beginning in Britain, industrialization in the 19th century brought urbanization, with wealth increasingly concentrated in the cities, which absorbed political power. However, as late as 1900, aristocrats maintained political dominance in Britain, Germany, Denmark, Sweden, Austria and Russia, but it was an increasingly-precarious dominion. The First World War had the effect of dramatically reducing the power of aristocrats in all major countries. In Russia, aristocrats were imprisoned and murdered by the communists. After 1900, liberal and socialist governments levied heavy taxes on landowners, spelling their loss of economic power. Sources. Aristocracy, from Wikipedia, the free encyclopedia
LIPS by The Internal Expression
The lips contribute substantially to facial expressions. The lips visibly express emotions such as a smile or frown, iconically by the curve of the lips forming an up-open or down-open parabola, respectively. Lips can also be made pouty when whining or perky to be provocative.
Lips are often viewed as a symbol of sensuality and sexuality. This has many origins; above all, the lips are a very sensitive erogenous and tactile organ. Furthermore, in many cultures of the world, a woman’s mouth and lips are veiled because of their representative association with the vulva, and because of their role as a woman’s secondary sexual organ.
As part of the mouth, the lips are also associated with the symbolism associated with the mouth as orifice by which food is taken in. The lips are also linked symbolically to neonatal psychology (see for example oral stage of the psychology according to Sigmund Freud).
Lip piercing or lip augmentation is sometimes carried out for cosmetic reasons. Products designed for use on the lips include lipstick, lip gloss and lip balm. Sources. The lips, from Wikipedia, the free encyclopedia
IMAGINE by The Internal Expression
Daydreaming is a stream of consciousness that detaches from current external tasks when one’s attention becomes focused on a more personal and internal direction.
Various names of this phenomenon exist, including mind-wandering, fantasies, and spontaneous thoughts. There are many types of daydreams – however, the most common characteristic to all forms of daydreaming meets the criteria for mild dissociation. In addition, the impacts of the various types of daydreams are not identical. While some are disruptive and deleterious, others may be beneficial to some degree.
The term daydreaming is derived from clinical psychologist Jerome L. Singer, whose research created the foundation for nearly all subsequent modern research. The terminologies assigned by modern researchers brings about challenges centering on identifying the common features of daydreaming and building collective work among researchers.
Characteristics and types of daydreaming:
Daydreaming consists of self-generated thoughts comprising three distinct categories: thoughts concerning the future and oneself, reflections on the past and others, and the emotional tone of experiences.
Psychologist Jerome L. Singer established three different types of daydreaming and their characteristics, varying in their cognitive states and emotional experiences. These included positive constructive daydreaming, characterized by constructive engagement, planning, pleasant thoughts, vivid imagery, and curiosity; guilty-dysphoric daydreaming, marked by obsessive, guilt-ridden, and anguished fantasies; and poor attentional control, reflecting difficulty focusing on either internal thoughts or external tasks.
Different daydreaming styles have various effects on certain behaviours, such as creativity.
Functions of daydreaming:
Future thinking
Daydreaming can be a useful tool to help keep people mindful of their relevant goals, such as imagining future success of a goal to motivate accomplishing a difficult or uninteresting task.
Creative thinking
This function of daydreaming is associated with increased creativity in individuals. The frequency of daydreaming is the highest during simple tasks. It is hypothesized that daydreaming plays an important role in generating creative problem-solving processes. Studies have found that intentional daydreaming is more effective when focused on creative thought processing, rather than spontaneous or disruptive daydreams.
Attentional cycling
Attentional cycling is an adaptive function of daydreaming through which a person’s attention may cycle through multiple target problems at the same time, helping the individual remain positive. When people have a variety of goals, daydreaming can provide an opportunity for people to alternate across different streams of information and thoughts in a healthy way.
Dishabituation
A change in the daydreaming state can lead to dishabituation, a function that can be beneficial during a learning process as it renews attention and interest in stimuli that have become repetitive. One research identified this effect in learning and showed that learning is more effective with distributed practices over time rather than massed practices all at once. Daydreaming can provide a break to allow thoughts to drift away from intensive learning . When you return, you will be able to focus again with the ability to continue focusing on attention-demanding tasks.
Relief from boredom
When people are performing mundane tasks, daydreaming allows their thoughts to detach from current external tasks to relieve boredom. At the same time, this temporary detachment will not stop external activities completely when they are necessary. As a result, daydreaming can cause the perception that time moves more quickly.
Visualizing social scenarios
Daydreaming can also be used to imagine social situations. Social daydreaming is imagining past social occurrences and future events and conversations. According to research, daydreaming and social cognition have strong overlapping similarities when activated portions of the brain are observed. These findings indicate that daydreaming is an extension of the brain’s experience of social cognition. This is likely because daydreams are often focused on the mental representations of social events, experiences, and people.
The correlation between social daydreaming and positive social relationships suggests that daydreaming about close others can enhance social well-being, reduce loneliness, and increase relationship satisfaction. Recent studies indicate that social daydreaming serves immediate socio-emotional regulation purposes, particularly in fostering feelings of love and connection, suggesting its adaptive role in achieving goals.
Default mode network
Main article: Default mode network
According to several studies, daydreaming appears to be the brain’s default setting when no other external task is occupying its attention. A group of regions in the brain called the default mode network is lit up only when the brain is left in a sort of ‘idle’ state. These areas of the brain light up in sequence only when daydreaming. Sources. From Daydreaming – Wikipedia, the free encyclopedia.
LONELY WOMAN by The Internal Expression
Loneliness is a feeling we all experience at times, but for some, it can be a constant companion. Women who are lonely in life often display these 6 behaviors without realizing it:
1) Masking emotions with busyness
One of the most common behaviors among women who unknowingly grapple with loneliness is filling every minute of their day with activities.
You might find yourself constantly on the move, ticking off items on your to-do list or juggling multiple projects at once. Your schedule rarely has a moment of stillness or downtime.
Why is this a potential sign of loneliness? By keeping busy, we often avoid dealing with the deep-seated feelings of isolation and disconnection that loneliness brings.
It’s a distraction, a way to keep our minds occupied so we don’t have to confront the pain of feeling alone.
The irony is that the busier we are, the less time we have for meaningful relationships and genuine connections, which deepens our sense of loneliness even more.
2) Excessive online presence
In an era where social media is king, and we’re more connected than ever, it might seem counterintuitive to suggest that a heightened online presence could indicate loneliness. However, the reality is often quite the opposite.
You might spend hours scrolling through social media feeds, posting updates regularly, or engaging in online forums and groups. It may seem like you’re connecting with others, but these connections can often be superficial.
3) Frequent mood swings
Mood swings can be a common symptom of many emotional states, but they can also be an indication of underlying loneliness.
You might notice that your moods fluctuate more frequently, from happiness to sudden sadness or irritability. These emotions may seem unprovoked, leaving you feeling confused and emotionally drained.
Loneliness can often manifest itself as an emotional rollercoaster. When we feel isolated, our emotions are heightened. We become more susceptible to negative thoughts and feelings, which can trigger these mood swings.
4) Excessive self-criticism
We all have moments of self-doubt and criticism, but when they become excessive, they might signal something deeper: loneliness.
You might constantly doubt your worth, criticize your every move, or feel you need to improve. These thoughts aren’t just passing clouds in your mind’s sky; they seem to have taken permanent residence.
Loneliness can often make us our own harshest critics. The isolation can magnify our flaws and shortcomings, causing us to be overly critical of ourselves.
This self-criticism can create a vicious cycle in which loneliness fuels self-doubt, and self-doubt, in turn, deepens the loneliness.
You’re not alone in feeling this way, and it’s more than okay to seek help and reach out to others.
5) Constant desire to help others
Being helpful and caring towards others is a beautiful trait, but sometimes, a constant desire to help can signal loneliness.
You might find yourself frequently being the one to lend a helping hand, offer advice, or go out of your way to make others feel comfortable. On the surface, you’re just naturally generous. But beneath that, it could be a plea for connection and recognition.
When we feel lonely, we often seek ways to feel valued and needed. Helping others can fulfill that need and temporarily distract us from our feelings of disconnection.
Suppose you find yourself constantly in ‘helping’ mode and neglecting your emotional well-being. In that case, it might be considered if you’re using this as a coping mechanism for loneliness.
It’s essential to prioritize your needs and seek help when needed.
6) Difficulty in establishing deep connections
Most people strive to form meaningful, lasting relationships. However, if establishing these deep connections is difficult, it could indicate underlying loneliness.
You might have many acquaintances or casual friends but few or no close, intimate relationships. You may struggle with opening up to others or letting them get close to you, resulting in superficial relationships.
We might worry that revealing our true selves will lead to rejection or judgment, causing us to keep others at arm’s length. This fear can prevent us from forming deep emotional connections to combat loneliness.
Understanding the complexities of loneliness
Loneliness is a complex emotion that can be hard to identify, especially in ourselves. It’s not simply about being physically alone; it’s a more profound sense of isolation that can persist even in a crowd.
It’s also crucial to understand that loneliness is not a personal failing or a sign of weakness. Acknowledging your feelings of loneliness is an act of courage.
If you’re struggling with loneliness, it’s okay to seek help. Reach out to friends or family members you trust and express your feelings.
Sources. Women who are lonely in life often display these 6 behaviors (without realizing it) by Ava Sinclair | February 2, 2024, 8:47 am
LOCOMOTIVE by The Internal Expression
A steam locomotive is a steam powered railway locomotive. It was used a lot between about 1830 and 1970. Afterwards, diesel and electric locomotives were used more often. The first steam locomotive was made by Richard Trevithick for a railway used for moving iron at an Ironworks in Wales.
A steam locomotive works by burning a fuel like coal in a special space called a firebox. This produces hot gases that rise and go through tubes in a boiler – a large space with water in it. This heats the water, producing steam. The steam is then taken through another tube to a cylinder. The steam then pushes the piston which in turn pushes a metal rod that is connected to the wheels, making the locomotive move. The steam then rises out through the chimney.
Steam locomotives are still today used in many developing countries where the railways have not yet been electrified. Sources. From Simple English – Wikipedia, the free encyclopedia.
ANIMALS by The Internal Expression
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor.
Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from 8.5 μm (0.00033 in) to 33.6 m (110 ft). They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviors is known as ethology.
Most living animal species belong to the infrakingdom Bilateria, a highly proliferative clade whose members have a bilaterally symmetric body plan. The vast majority belong to two large superphyla: the protostomes, which includes organisms such as the arthropods, molluscs, flatworms, annelids and nematodes; and the deuterostomes, which include the echinoderms, hemichordates and chordates, the latter of which contains the vertebrates. The simple Xenacoelomorpha have an uncertain position within Bilateria.
Animals first appear in the fossil record in the late Cryogenian period and diversified in the subsequent Ediacaran. Earlier evidence of animals is still controversial; the sponge-like organism Otavia has been dated back to the Tonian period at the start of the Neoproterozoic, but its identity as an animal is heavily contested. Nearly all modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 539 million years ago (Mya), and most classes during the Ordovician radiation 485.4 Mya. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived about 650 Mya during the Cryogenian period.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous with Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between taxa.
Humans make use of many other animal species for food (including meat, eggs, and dairy products), for materials (such as leather, fur, and wool), as pets and as working animals for transportation, and services. Dogs, the first domesticated animal, have been used in hunting, in security and in warfare, as have horses, pigeons and birds of prey; while other terrestrial and aquatic animals are hunted for sports, trophies or profits. Non-human animals are also an important cultural element of human evolution, having appeared in cave arts and totems since the earliest times, and are frequently featured in mythology, religion, arts, literature, heraldry, politics, and sports.
The word animal comes from the Latin noun animal of the same meaning, which is itself derived from Latin animalis ‘having breath or soul’. The biological definition includes all members of the kingdom Animalia. In colloquial usage, the term animal is often used to refer only to nonhuman animals. The term metazoa is derived from Ancient Greek μετα (meta) ‘after’ (in biology, the prefix meta- stands for ‘later’) and ζῷᾰ (zōia) ‘animals’, plural of ζῷον zōion ‘animal’. Sources. From Animal – Wikipedia, the free encyclopedia.