The mind is a set of cognitive faculties including consciousness, perception, judgement and memory. It is defined as the faculty of an entity's thoughts and consciousness, it holds the power of imagination and appreciation, is responsible for processing feelings and emotions, resulting in attitudes and actions. There is a lengthy tradition in philosophy, religion and cognitive science about what constitutes a mind and what are its distinguishing properties. One open question regarding the nature of the mind is the mind–body problem, which investigates the relation of the mind to the physical brain and nervous system. Older viewpoints included idealism, which considered the mind somehow non-physical. Modern views center around physicalism and functionalism, which hold that the mind is identical with the brain or reducible to physical phenomena such as neuronal activity, though dualism and idealism continue to have many supporters. Another question concerns. For example, whether mind is exclusive to humans, possessed by some or all animals, by all living things, whether it is a definable characteristic at all, or whether mind can be a property of some types of human-made machines.
Whatever its nature, it is agreed that mind is that which enables a being to have subjective awareness and intentionality towards their environment, to perceive and respond to stimuli with some kind of agency, to have consciousness, including thinking and feeling. The concept of mind is understood in many different ways by many different cultural and religious traditions; some see mind as a property exclusive to humans whereas others ascribe properties of mind to non-living entities, to animals and to deities. Some of the earliest recorded speculations linked mind to theories concerning both life after death, cosmological and natural order, for example in the doctrines of Zoroaster, the Buddha, Plato and other ancient Greek and Islamic and medieval European philosophers. Important philosophers of mind include Plato, Descartes, Locke, Hume, Hegel, Searle, Fodor and Chalmers. Psychologists such as Freud and James, computer scientists such as Turing and Putnam developed influential theories about the nature of the mind.
The possibility of nonbiological minds is explored in the field of artificial intelligence, which works in relation with cybernetics and information theory to understand the ways in which information processing by nonbiological machines is comparable or different to mental phenomena in the human mind. The mind is portrayed as the stream of consciousness where sense impressions and mental phenomena are changing; the original meaning of Old English gemynd was the faculty of memory, not of thought in general. Hence call to mind, come to mind, keep in mind, to have mind of, etc; the word retains this sense in Scotland. Old English had other words to express "mind", such as hyge "mind, spirit"; the meaning of "memory" is shared with Old Norse. The word is from a PIE verbal root *men-, meaning "to think, remember", whence Latin mens "mind", Sanskrit manas "mind" and Greek μένος "mind, anger"; the generalization of mind to include all mental faculties, volition and memory develops over the 14th and 15th centuries.
The attributes that make up the mind are debated. Some psychologists argue that only the "higher" intellectual functions constitute mind reason and memory. In this view the emotions — love, hate and joy — are more primitive or subjective in nature and should be seen as different from the mind as such. Others argue that various rational and emotional states cannot be so separated, that they are of the same nature and origin, should therefore be considered all part of it as mind. In popular usage, mind is synonymous with thought: the private conversation with ourselves that we carry on "inside our heads." Thus we "make up our minds," "change our minds" or are "of two minds" about something. One of the key attributes of the mind in this sense is that it is a private sphere to which no one but the owner has access. No one else can "know our mind." They can only interpret or unconsciously communicate. Broadly speaking, mental faculties are the various functions of the mind, or things the mind can "do".
Thought is a mental act that allows humans to make sense of things in the world, to represent and interpret them in ways that are significant, or which accord with their needs, goals, plans, desires, etc. Thinking involves the symbolic or semiotic mediation of ideas or data, as when we form concepts, engage in problem solving and making decisions. Words that refer to similar concepts and processes include deliberation, ideation and imagination. Thinking is sometimes described as a "higher" cognitive function and the analysis of thinking processes is a part of cognitive psychology, it is deeply connected with our capacity to make and use tools. Memory is the ability to preserve and subsequently recall, information or experience. Although memory has traditionally been a persistent theme in philosophy, the late nineteenth and early twentieth centuries
The Anthropocene is a proposed epoch dating from the commencement of significant human impact on the Earth's geology and ecosystems, but not limited to, anthropogenic climate change. As of August 2016, neither the International Commission on Stratigraphy nor the International Union of Geological Sciences has yet approved the term as a recognized subdivision of geological time, although the Anthropocene Working Group of the Subcommission on Quaternary Stratigraphy of the International Commission on Stratigraphy, voted to proceed towards a formal golden spike proposal to define the Anthropocene epoch in the Geologic Time Scale and presented the recommendation to the International Geological Congress on 29 August 2016. Various different start dates for the Anthropocene have been proposed, ranging from the beginning of the Agricultural Revolution 12,000–15,000 years ago, to as recent as the Trinity test in 1945; as of February 2018, the ratification process continues and thus a date remains to be decided definitively, but the latter date has been more favoured than others.
The most recent period of the Anthropocene has been referred to by several authors as the Great Acceleration during which the socioeconomic and earth system trends are increasing especially after the Second World War. For instance, the Geological Society termed the year 1945 as The Great Acceleration. An early concept for the Anthropocene was the Noosphere by Vladimir Vernadsky, who in 1938 wrote of "scientific thought as a geological force." Scientists in the Soviet Union appear to have used the term "anthropocene" as early as the 1960s to refer to the Quaternary, the most recent geological period. Ecologist Eugene F. Stoermer subsequently used "anthropocene" with a different sense in the 1980s and the term was popularized in 2000 by atmospheric chemist Paul J. Crutzen, who regards the influence of human behavior on Earth's atmosphere in recent centuries as so significant as to constitute a new geological epoch. In 2008, the Stratigraphy Commission of the Geological Society of London considered a proposal to make the Anthropocene a formal unit of geological epoch divisions.
A majority of the commission decided the proposal should be examined further. Independent working groups of scientists from various geological societies have begun to determine whether the Anthropocene will be formally accepted into the Geological Time Scale; the term "anthropocene" is informally used in scientific contexts. The Geological Society of America entitled its 2011 annual meeting: Archean to Anthropocene: The past is the key to the future; the new epoch has no agreed start-date, but one proposal, based on atmospheric evidence, is to fix the start with the Industrial Revolution ca. 1780, with the invention of the steam engine. Other scientists link the new term to earlier events, such as the rise of agriculture and the Neolithic Revolution. Evidence of relative human impact – such as the growing human influence on land use, ecosystems and species extinction – is substantial; those arguing for earlier dates posit that the proposed Anthropocene may have begun as early as 14,000 to 15,000 years before present, based on geologic evidence.
In January 2015, 26 of the 38 members of the International Anthropocene Working Group published a paper suggesting the Trinity test on 16 July 1945 as the starting point of the proposed new epoch. However, a significant minority supports one of several alternative dates. A March 2015 report suggested either 1964 as the beginning of Anthropocene. Other scholars point to the diachronous character of the physical strata of the Anthropocene, arguing that onset and impact are spread out over time, not reducible to a single instant or date of start. A January 2016 report on the climatic and geochemical signatures of human activity in sediments and ice cores suggested the era since the mid-20th century should be recognised as a geological epoch distinct from the Holocene; the Anthropocene Working Group met in Oslo in April 2016 to consolidate evidence supporting the argument for the Anthropocene as a true geologic epoch. Evidence was evaluated and the group voted to recommend "Anthropocene" as the new geological age in August 2016.
Should the International Commission on Stratigraphy approve the recommendation, the proposal to adopt the term will have to be ratified by the IUGS before its formal adoption as part of the geologic time scale. The name Anthropocene is a combination of anthropo- from anthropos meaning "human" and -cene from kainos meaning "new" or "recent."As early as 1873, the Italian geologist Antonio Stoppani acknowledged the increasing power and effect of humanity on the Earth's systems and referred to an'anthropozoic era'. Although the biologist Eugene Stoermer is credited with coining the term "anthropocene", it was in informal use in the mid-1970s. Paul Crutzen is credited with independently popularizing it. Stoermer wrote, "I began using the term'anthropocene' in the 1980's, but never formalized it until Paul contacted me." Crutzen has explained, "I was at a conference. I thought this was wrong; the world has changed too much. So I said:'No, we are in the Anthropocene.' I just made up the word on the spur of the moment.
Everyone was shocked. But it seems to have stuck." In 2008, Zalasiewicz suggested in GSA Today that an anthropocene epoch is
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with artificial selection, which in his view is intentional, whereas natural selection is not. Variation exists within all populations of organisms; this occurs because random mutations arise in the genome of an individual organism, offspring can inherit such mutations. Throughout the lives of the individuals, their genomes interact with their environments to cause variations in traits; the environment of a genome includes the molecular biology in the cell, other cells, other individuals, species, as well as the abiotic environment. Because individuals with certain variants of the trait tend to survive and reproduce more than individuals with other, less successful variants, the population evolves.
Other factors affecting reproductive success include fecundity selection. Natural selection acts on the phenotype, the characteristics of the organism which interact with the environment, but the genetic basis of any phenotype that gives that phenotype a reproductive advantage may become more common in a population. Over time, this process can result in populations that specialise for particular ecological niches and may result in speciation. In other words, natural selection is a key process in the evolution of a population. Natural selection is a cornerstone of modern biology; the concept, published by Darwin and Alfred Russel Wallace in a joint presentation of papers in 1858, was elaborated in Darwin's influential 1859 book On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. He described natural selection as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favoured for reproduction.
The concept of natural selection developed in the absence of a valid theory of heredity. The union of traditional Darwinian evolution with subsequent discoveries in classical genetics formed the modern synthesis of the mid-20th century; the addition of molecular genetics has led to evolutionary developmental biology, which explains evolution at the molecular level. While genotypes can change by random genetic drift, natural selection remains the primary explanation for adaptive evolution. Several philosophers of the classical era, including Empedocles and his intellectual successor, the Roman poet Lucretius, expressed the idea that nature produces a huge variety of creatures and that only those creatures that manage to provide for themselves and reproduce persist. Empedocles' idea that organisms arose by the incidental workings of causes such as heat and cold was criticised by Aristotle in Book II of Physics, he posited natural teleology in its place, believed that form was achieved for a purpose, citing the regularity of heredity in species as proof.
He accepted in his biology that new types of animals, can occur in rare instances. As quoted in Darwin's 1872 edition of The Origin of Species, Aristotle considered whether different forms might have appeared accidentally, but only the useful forms survived: So what hinders the different parts from having this accidental relation in nature? as the teeth, for example, grow by necessity, the front ones sharp, adapted for dividing, the grinders flat, serviceable for masticating the food. And in like manner as to the other parts in which there appears to exist an adaptation to an end. Wheresoever, all things together happened like as if they were made for the sake of something, these were preserved, having been appropriately constituted by an internal spontaneity, whatsoever things were not thus constituted and still perish, but Aristotle rejected this possibility in the next paragraph, making clear that he is talking about the development of animals as embryos with the phrase "either invariably or come about", not the origin of species:...
Yet it is impossible. For teeth and all other natural things either invariably or come about in a given way. We do not ascribe to chance or mere coincidence the frequency of rain in winter, but frequent rain in summer we do. If it is agreed that things are either the result of coincidence or for an end, these cannot be the result of coincidence or spontaneity, it follows that they must be for an end; therefore action for an end is present in things which are by nature. The struggle for existence was described by the Islamic writer Al-Jahiz in the 9th century; the classical arguments were reintroduced in the 18th century by Pierre Louis Maupertuis and others, including Darwin's grandfather, Erasmus Darwin. Until the early 19th century, the prevailing view in Western societies was that differences between individuals of a species were uninteresting departures from their Platonic i
University of Paris
The University of Paris, metonymically known as the Sorbonne, was a university in Paris, active 1150–1793, 1806–1970. Emerging around 1150 as a corporation associated with the cathedral school of Notre Dame de Paris, it was considered the second oldest university in Europe. Chartered in 1200 by King Philip II of France and recognised in 1215 by Pope Innocent III, it was often nicknamed after its theological College of Sorbonne, in turn founded by Robert de Sorbon and chartered by French King Saint Louis around 1257. Internationally reputed for its academic performance in the humanities since the Middle Ages – notably in theology and philosophy – it introduced several academic standards and traditions that have endured since and spread internationally, such as doctoral degrees and student nations. Vast numbers of popes, royalty and intellectuals were educated at the University of Paris. A few of the colleges of the time are still visible close to Pantheon and Luxembourg Gardens: Collège des Bernardins, Hotel de Cluny, College Sainte Barbe, College d'Harcourt, Cordeliers.
In 1793, during the French Revolution, the university was closed and by Item-27 of the Revolutionary Convention, the college endowments and buildings were sold. A new University of France replaced it in 1806 with four independent faculties: the Faculty of Humanities, the Faculty of Law, the Faculty of Science, the Faculty of Medicine and the Faculty of Theology. In 1970, following the May 1968 events, the university was divided into 13 autonomous universities. Although all the thirteen universities that resulted of the original University of Paris split can be considered its inheritors, just three universities of the post-1968 universities embodied direct faculties successors while inheriting the name "Sorbonne", as well as its physical location in the Latin Quarter: the Pantheon-Sorbonne University. From 2010, University of Paris successors started to reorganise themselves into different groups of universities and institutions that were upgraded to "pôles de recherche et d'enseignement supérieur".
As a result, various university groups exist in the Paris area, among them Sorbonne Paris Cité, Sorbonne Universities, the University of Paris-Saclay, Paris Lumiéres, Paris-Seine, so on. In January 2018, two of the inheritors of the old University of Paris, Paris-Sorbonne University and Pierre and Marie Curie University, merged into a single university called Sorbonne University. In 2019, two other inheritors of the University of Paris, namely Paris Diderot University and Paris Descartes University, are expected to merge. In 1150, the future University of Paris was a student-teacher corporation operating as an annex of the Notre-Dame cathedral school; the earliest historical reference to it is found in Matthew of Paris' reference to the studies of his own teacher and his acceptance into "the fellowship of the elect Masters" there in about 1170, it is known that Pope Innocent III completed his studies there in 1182 at the age of 21. The corporation was formally recognised as an "Universitas" in an edict by King Philippe-Auguste in 1200: in it, among other accommodations granted to future students, he allowed the corporation to operate under ecclesiastic law which would be governed by the elders of the Notre-Dame Cathedral school, assured all those completing courses there that they would be granted a diploma.
The university had four faculties: Arts, Medicine and Theology. The Faculty of Arts was the lowest in rank, but the largest, as students had to graduate there in order to be admitted to one of the higher faculties; the students were divided into four nationes according to language or regional origin: France, Normandy and England. The last came to be known as the Alemannian nation. Recruitment to each nation was wider than the names might imply: the English-German nation included students from Scandinavia and Eastern Europe; the faculty and nation system of the University of Paris became the model for all medieval universities. Under the governance of the Church, students wore robes and shaved the tops of their heads in tonsure, to signify they were under the protection of the church. Students followed the rules and laws of the Church and were not subject to the king's laws or courts; this presented problems for the city of Paris, as students ran wild, its official had to appeal to Church courts for justice.
Students were very young, entering the school at 13 or 14 years of age and staying for six to 12 years. Three schools were famous in Paris: the palatine or palace school, the school of Notre-Dame, that of Sainte-Geneviève Abbey; the decline of royalty brought about the decline of the first. The other two did not have much visibility in the early centuries; the glory of the palatine school doubtless eclipsed theirs, until it gave way to them. These two centres were much frequented and many of their masters were esteemed for their learning; the first renowned professor at the school of Ste-Geneviève was Hubold, who lived in the tenth century. Not content with the courses at Liège, he continued his studies at Paris, entered or allied himself with the chapter of Ste-Geneviève, attracted many pupils via his teaching. Distinguished professors from the school of Notre-Dame in the eleventh century incl
Consciousness is the state or quality of awareness or of being aware of an external object or something within oneself. It has been defined variously in terms of sentience, qualia, the ability to experience or to feel, having a sense of selfhood or soul, the fact that there is something "that it is like" to "have" or "be" it, the executive control system of the mind. Despite the difficulty in definition, many philosophers believe that there is a broadly shared underlying intuition about what consciousness is; as Max Velmans and Susan Schneider wrote in The Blackwell Companion to Consciousness: "Anything that we are aware of at a given moment forms part of our consciousness, making conscious experience at once the most familiar and most mysterious aspect of our lives."Western philosophers, since the time of Descartes and Locke, have struggled to comprehend the nature of consciousness and identify its essential properties. Issues of concern in the philosophy of consciousness include whether the concept is fundamentally coherent.
Thanks to developments in technology over the past few decades, consciousness has become a significant topic of interdisciplinary research in cognitive science, with significant contributions from fields such as psychology, anthropology and neuroscience. The primary focus is on understanding what it means biologically and psychologically for information to be present in consciousness—that is, on determining the neural and psychological correlates of consciousness; the majority of experimental studies assess consciousness in humans by asking subjects for a verbal report of their experiences. Issues of interest include phenomena such as subliminal perception, denial of impairment, altered states of consciousness produced by alcohol and other drugs, or spiritual or meditative techniques. In medicine, consciousness is assessed by observing a patient's arousal and responsiveness, can be seen as a continuum of states ranging from full alertness and comprehension, through disorientation, loss of meaningful communication, loss of movement in response to painful stimuli.
Issues of practical concern include how the presence of consciousness can be assessed in ill, comatose, or anesthetized people, how to treat conditions in which consciousness is impaired or disrupted. The degree of consciousness is measured by standardized behavior observation scales such as the Glasgow Coma Scale; the origin of the modern concept of consciousness is attributed to John Locke's Essay Concerning Human Understanding, published in 1690. Locke defined consciousness as "the perception of what passes in a man's own mind", his essay influenced the 18th-century view of consciousness, his definition appeared in Samuel Johnson's celebrated Dictionary. "Consciousness" is defined in the 1753 volume of Diderot and d'Alembert's Encyclopédie, as "the opinion or internal feeling that we ourselves have from what we do." The earliest English language uses of "conscious" and "consciousness" date back, however, to the 1500s. The English word "conscious" derived from the Latin conscius, but the Latin word did not have the same meaning as our word—it meant "knowing with", in other words "having joint or common knowledge with another".
There were, many occurrences in Latin writings of the phrase conscius sibi, which translates as "knowing with oneself", or in other words "sharing knowledge with oneself about something". This phrase had the figurative meaning of "knowing that one knows", as the modern English word "conscious" does. In its earliest uses in the 1500s, the English word "conscious" retained the meaning of the Latin conscius. For example, Thomas Hobbes in Leviathan wrote: "Where two, or more men, know of one and the same fact, they are said to be Conscious of it one to another." The Latin phrase conscius sibi, whose meaning was more related to the current concept of consciousness, was rendered in English as "conscious to oneself" or "conscious unto oneself". For example, Archbishop Ussher wrote in 1613 of "being so conscious unto myself of my great weakness". Locke's definition from 1690 illustrates. A related word was conscientia, which means moral conscience. In the literal sense, "conscientia" means knowledge-with, that is, shared knowledge.
The word first appears in Latin juridical texts by writers such as Cicero. Here, conscientia is the knowledge. René Descartes is taken to be the first philosopher to use conscientia in a way that does not fit this traditional meaning. Descartes used conscientia the way modern speakers would use "conscience". In Search after Truth he says "conscience or internal testimony"; the dictionary meanings of the word consciousness extend through several centuries and several associated related meanings. These have ranged from formal definitions to definitions attempting to capture the less captured and more debated meanings and usage of the wor
The biosphere known as the ecosphere, is the worldwide sum of all ecosystems. It can be termed the zone of life on Earth, a closed system, self-regulating. By the most general biophysiological definition, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, geosphere and atmosphere; the biosphere is postulated to have evolved, beginning with a process of biopoiesis or biogenesis, at least some 3.5 billion years ago. In a general sense, biospheres are any self-regulating systems containing ecosystems; this includes artificial biospheres such as Biosphere 2 and BIOS-3, ones on other planets or moons. The term "biosphere" was coined by geologist Eduard Suess in 1875, which he defined as the place on Earth's surface where life dwells. While the concept has a geological origin, it is an indication of the effect of both Charles Darwin and Matthew F. Maury on the Earth sciences; the biosphere's ecological context comes from the 1920s, preceding the 1935 introduction of the term "ecosystem" by Sir Arthur Tansley.
Vernadsky defined ecology as the science of the biosphere. It is an interdisciplinary concept for integrating astronomy, meteorology, evolution, geochemistry and speaking, all life and Earth sciences. Geochemists define the biosphere as being the total sum of living organisms. In this sense, the biosphere is but one of four separate components of the geochemical model, the other three being geosphere and atmosphere; when these four component spheres are combined into one system, it is known as the Ecosphere. This term was coined during the 1960s and encompasses both biological and physical components of the planet; the Second International Conference on Closed Life Systems defined biospherics as the science and technology of analogs and models of Earth's biosphere. Others may include the creation of artificial non-Earth biospheres—for example, human-centered biospheres or a native Martian biosphere—as part of the topic of biospherics; the earliest evidence for life on Earth includes biogenic graphite found in 3.7 billion-year-old metasedimentary rocks from Western Greenland and microbial mat fossils found in 3.48 billion-year-old sandstone from Western Australia.
More in 2015, "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia. In 2017, putative fossilized microorganisms were announced to have been discovered in hydrothermal vent precipitates in the Nuvvuagittuq Belt of Quebec, Canada that were as old as 4.28 billion years, the oldest record of life on earth, suggesting "an instantaneous emergence of life" after ocean formation 4.4 billion years ago, not long after the formation of the Earth 4.54 billion years ago. According to biologist Stephen Blair Hedges, "If life arose quickly on Earth... it could be common in the universe." Every part of the planet, from the polar ice caps to the equator, features life of some kind. Recent advances in microbiology have demonstrated that microbes live deep beneath the Earth's terrestrial surface, that the total mass of microbial life in so-called "uninhabitable zones" may, in biomass, exceed all animal and plant life on the surface; the actual thickness of the biosphere on earth is difficult to measure.
Birds fly at altitudes as high as 1,800 m and fish live as much as 8,372 m underwater in the Puerto Rico Trench. There are more extreme examples for life on the planet: Rüppell's vulture has been found at altitudes of 11,300 m. Herbivorous animals at these elevations depend on lichens and herbs. Life forms live in every part of the Earth's biosphere, including soil, hot springs, inside rocks at least 19 km deep underground, the deepest parts of the ocean, at least 64 km high in the atmosphere. Microorganisms, under certain test conditions, have been observed to survive the vacuum of outer space; the total amount of soil and subsurface bacterial carbon is estimated as 5 × 1017 g, or the "weight of the United Kingdom". The mass of prokaryote microorganisms—which includes bacteria and archaea, but not the nucleated eukaryote microorganisms—may be as much as 0.8 trillion tons of carbon. Barophilic marine microbes have been found at more than a depth of 10,000 m in the Mariana Trench, the deepest spot in the Earth's oceans.
In fact, single-celled life forms have been found in the deepest part of the Mariana Trench, by the Challenger Deep, at depths of 11,034 m. Other researchers reported related studies that microorganisms thrive inside rocks up to 580 m below the sea floor under 2,590 m of ocean off the coast of the northwestern United States, as well as 2,400 m beneath the seabed off Japan. Culturable thermophilic microbes have been extracted from cores drilled more than 5,000 m (1
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes that are passed on from parent to offspring during reproduction. Different characteristics tend to exist within any given population as a result of mutation, genetic recombination and other sources of genetic variation. Evolution occurs when evolutionary processes such as natural selection and genetic drift act on this variation, resulting in certain characteristics becoming more common or rare within a population, it is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms and molecules. The scientific theory of evolution by natural selection was proposed by Charles Darwin and Alfred Russel Wallace in the mid-19th century and was set out in detail in Darwin's book On the Origin of Species. Evolution by natural selection was first demonstrated by the observation that more offspring are produced than can survive.
This is followed by three observable facts about living organisms: 1) traits vary among individuals with respect to their morphology and behaviour, 2) different traits confer different rates of survival and reproduction and 3) traits can be passed from generation to generation. Thus, in successive generations members of a population are more to be replaced by the progenies of parents with favourable characteristics that have enabled them to survive and reproduce in their respective environments. In the early 20th century, other competing ideas of evolution such as mutationism and orthogenesis were refuted as the modern synthesis reconciled Darwinian evolution with classical genetics, which established adaptive evolution as being caused by natural selection acting on Mendelian genetic variation. All life on Earth shares a last universal common ancestor that lived 3.5–3.8 billion years ago. The fossil record includes a progression from early biogenic graphite, to microbial mat fossils, to fossilised multicellular organisms.
Existing patterns of biodiversity have been shaped by repeated formations of new species, changes within species and loss of species throughout the evolutionary history of life on Earth. Morphological and biochemical traits are more similar among species that share a more recent common ancestor, can be used to reconstruct phylogenetic trees. Evolutionary biologists have continued to study various aspects of evolution by forming and testing hypotheses as well as constructing theories based on evidence from the field or laboratory and on data generated by the methods of mathematical and theoretical biology, their discoveries have influenced not just the development of biology but numerous other scientific and industrial fields, including agriculture and computer science. The proposal that one type of organism could descend from another type goes back to some of the first pre-Socratic Greek philosophers, such as Anaximander and Empedocles; such proposals survived into Roman times. The poet and philosopher Lucretius followed Empedocles in his masterwork De rerum natura.
In contrast to these materialistic views, Aristotelianism considered all natural things as actualisations of fixed natural possibilities, known as forms. This was part of a medieval teleological understanding of nature in which all things have an intended role to play in a divine cosmic order. Variations of this idea became the standard understanding of the Middle Ages and were integrated into Christian learning, but Aristotle did not demand that real types of organisms always correspond one-for-one with exact metaphysical forms and gave examples of how new types of living things could come to be. In the 17th century, the new method of modern science rejected the Aristotelian approach, it sought explanations of natural phenomena in terms of physical laws that were the same for all visible things and that did not require the existence of any fixed natural categories or divine cosmic order. However, this new approach was slow to take root in the biological sciences, the last bastion of the concept of fixed natural types.
John Ray applied one of the more general terms for fixed natural types, "species," to plant and animal types, but he identified each type of living thing as a species and proposed that each species could be defined by the features that perpetuated themselves generation after generation. The biological classification introduced by Carl Linnaeus in 1735 explicitly recognised the hierarchical nature of species relationships, but still viewed species as fixed according to a divine plan. Other naturalists of this time speculated on the evolutionary change of species over time according to natural laws. In 1751, Pierre Louis Maupertuis wrote of natural modifications occurring during reproduction and accumulating over many generations to produce new species. Georges-Louis Leclerc, Comte de Buffon suggested that species could degenerate into different organisms, Erasmus Darwin proposed that all warm-blooded animals could have descended from a single microorganism; the first full-fledged evolutionary scheme was Jean-Baptiste Lamarck's "transmutation" theory of 1809, which envisaged spontaneous generation continually producing simple forms of life that developed greater complexity in parallel lineages with an inherent progressive tendency, postulated that on a local level, these lineages adapted to the environment by inheriting changes caused by their use or disuse in parents.
These ideas were cond