santosh chaudhary

WHAT IS LIFE

Life (cf. biota) is a characteristic that distinguishes objects that have signaling and self-sustaining processes (i. e., living organisms) from those that do not,[1][2] either because such functions have ceased (death), or else because they lack such functions and are classified as inanimate.[3][4] Biology is the science concerned with the study of life. Living organisms undergo metabolism, maintain homeostasis, possess a capacity to grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment in successive generations. More complex living organisms can communicate through various means.[1][5] A diverse array of living organisms (life forms) can be found in the biosphere on Earth, and the properties common to these organisms—plants, animals, fungi, protists, archaea, and bacteria—are a carbon- and water-based cellular form with complex organization and heritable genetic information. In philosophy and religion, the conception of life and its nature varies. Both offer interpretations as to how life relates to existence and consciousness, and both touch on many related issues, including life stance, purpose, conception of a god or gods, a soul or an afterlife

Materialism

Hylomorphism

Vitalism

Definitions

Biology

Since there is no unequivocal definition of life, the current understanding is descriptive, where life is a characteristic of organisms that exhibit all or most of the following # Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature. # Organization: Being structurally composed of one or more cells, which are the basic units of life. # Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life. # Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter. # Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present. # Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun (phototropism) and by chemotaxis. # Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms

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HUMAN LIFE

Etymology

History

Evolution

Main article: Human evolution Further information: Anthropology, Homo (genus), and Timeline of human evolution Plesiadapis A reconstruction of Australopithecus afarensis, a human ancestor that had developed bipedalism, but which lacked the large brain of modern humans The scientific study of human evolution encompasses the development of the genus Homo, but usually involves studying other hominids and hominines as well, such as Australopithecus. "Modern humans" are defined as the Homo sapiens species, of which the only extant subspecies is known as Homo sapiens sapiens. Homo sapiens idaltu (roughly translated as "elder wise human"), the other known subspecies, is now extinct.[16] Homo neanderthalensis, which became extinct 30,000 years ago, has sometimes been classified as a subspecies, "Homo sapiens neanderthalensis"; genetic studies now suggest that the functional DNA of modern humans and Neanderthals diverged 500,000 years ago.[17] Similarly, the few specimens of Homo rhodesiensis have also occasionally been classified as a subspecies, but this is not widely accepted. Anatomically modern humans first appear in the fossil record in Africa about 195,000 years ago, and studies of molecular biology give evidence that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago.[18][19][20][21][22] The broad study of African genetic diversity headed by Dr. Sarah Tishkoff found the San people to express the greatest genetic diversity among the 113 distinct populations sampled, making them one of 14 "ancestral population clusters". The research also located the origin of modern human migration in south-western Africa, near the coastal border of Namibia and Angola.[23] The evolutionary history of the primates can be traced back 65 million years, as one of the oldest of all surviving placental mammal groups. The oldest known primate-like mammal species (those of the genus Plesiadapis) come from North America, but they were widespread in Eurasia and Africa during the tropical conditions of the Paleocene and Eocene. Molecular evidence suggests that the last common ancestor between humans and the remaining great apes diverged between 8 and 4 million years ago, first the gorillas, and then the chimpanzees (genus Pan) split off from the line leading to the humans; the functional human DNA is approximately 98.4% identical to that of chimpanzees when comparing single nucleotide polymorphisms (see human evolutionary genetics). Therefore, the closest living relatives of humans are gorillas and chimpanzees, as they share a common ancestor.[24] Humans are probably most closely related to two chimpanzee species: Common Chimpanzee and Bonobo.[24] Full genome sequencing has resulted in the conclusion that "after 6.5 [million] years of separate evolution, the differences between chimpanzee and human are ten times greater than those between two unrelated people and ten times less than those between rats and mice".[attribution needed] Suggested concurrence between the functional human and chimpanzee DNA sequences range between 95% and 99%;[25][26][27][28] It has been estimated that the human lineage diverged from that of chimpanzees about five million years ago, and from that of gorillas about eight million years ago. However, a hominid skull discovered in Chad in 2001, classified as Sahelanthropus tchadensis, is approximately seven million years old, which may indicate an earlier divergence.[29] Human evolution is characterised by a number of important morphological, developmental, physiological and behavioural changes, which have taken place since the split between the last common ancestor of humans and chimpanzees. The first major morphological change was the evolution of a bipedal locomotor adaptation from an arboreal or semi-arboreal one,[30] with all its attendant adaptations, such as a valgus knee, low intermembral index (long legs relative to the arms), and reduced upper-body strength. Later, ancestral humans developed a much larger brain – typically 1,400 cm³ in modern humans, over twice the size of that of a chimpanzee or gorilla. The pattern of human postnatal brain growth differs from that of other apes (heterochrony), and allows for extended periods of social learning and language acquisition in juvenile humans. Physical anthropologists[who?] argue that the differences between the structure of human brains and those of other apes are even more significant than their differences in size. Other significant morphological changes included the evolution of a power and precision grip,[31] a reduced masticatory system, a reduction of the canine tooth, and the descent of the larynx and hyoid bone, making speech possible. An important physiological change in humans was the evolution of hidden oestrus, or concealed ovulation, which may have coincided with the evolution of important behavioural changes, such as pair bonding. Another significant behavioural change was the development of material culture, with human-made objects becoming increasingly common and diversified over time. The relationship between all these changes is the subject of ongoing debate.[32][33] The forces of natural selection have continued to operate on human populations, with evidence that certain regions of the genome display directional selection in the past 15,000 years

Paleolithic

Further information: Recent African Origin, Archaic Homo sapiens, Upper Paleolithic, and Early human migrations Artistic expression appeared in the Upper Paleolithic: The Venus of Dolní Vestonice figurine, one of the earliest known depictions of the human body, dates to approximately 29,000–25,000 BP (Gravettian). Anatomically modern humans evolved from archaic Homo sapiens in Africa in the Middle Paleolithic, about 200,000 years ago. By the beginning of the Upper Paleolithic 50,000 BP (Before Present), full behavioral modernity, including language, music and other cultural universals had developed. The out of Africa migration is estimated to have occurred about 70,000 years BP. Modern humans subsequently spread to all continents, replacing earlier hominids: they inhabited Eurasia and Oceania by 40,000 BP, and the Americas at least 14,500 years BP.[35] A popular theory is that they displaced Homo neanderthalensis and other species descended from Homo erectus[36] (which had inhabited Eurasia as early as 2 million years ago) through more successful reproduction and competition for resources.[37] The exact manner or extent of the coexistence and interaction of these species is unknown and remains a controversial subject.[citation needed] Evidence from archaeogenetics accumulating since the 1990s has lent strong support to the "out-of-Africa" scenario, and has marginalized the competing multiregional hypothesis, which proposed that modern humans evolved, at least in part, from independent hominid populations.[38] Geneticists Lynn Jorde and Henry Harpending of the University of Utah propose that the variation in human DNA is minute compared to that of other species. They also propose that during the Late Pleistocene, the human population was reduced to a small number of breeding pairs – no more than 10,000, and possibly as few as 1,000 – resulting in a very small residual gene pool. Various reasons for this hypothetical bottleneck have been postulated, one being the Toba catastrophe theory

Transition to civilization

Main articles: Neolithic revolution and Cradle of Civilization Further information: History of the world The rise of agriculture, and domestication of animals, led to stable human settlements. The path followed by humans in the course of history Until c. 10,000 years ago, most humans lived as hunter-gatherers. They generally lived in small nomadic groups known as band societies. The advent of agriculture prompted the Neolithic Revolution, when access to food surplus led to the formation of permanent human settlements, the domestication of animals and the use of metal tools. Agriculture encouraged trade and cooperation, and led to complex society. Because of the significance of this date for human society, it is the epoch of the Holocene calendar or Human Era. About 6,000 years ago, the first proto-states developed in Mesopotamia, Egypt's Nile Valley and the Indus Valleys. Military forces were formed for protection, and government bureaucracies for administration. States cooperated and competed for resources, in some cases waging wars. Around 2,000–3,000 years ago, some states, such as Persia, India, China, Rome, and Greece, developed through conquest into the first expansive empires. Influential religions, such as Judaism, originating in West Asia, and Hinduism, a religious tradition that originated in South Asia, also rose to prominence at this time. The late Middle Ages saw the rise of revolutionary ideas and technologies. In China, an advanced and urbanized society promoted innovations and sciences, such as printing and seed drilling. In India, major advancements were made in mathematics, philosophy, religion and metallurgy. The Islamic Golden Age saw major scientific advancements in Muslim empires. In Europe, the rediscovery of classical learning and inventions such as the printing press led to the Renaissance in the 14th and 15th centuries. Over the next 500 years, exploration and colonialism brought great parts of the world under European control, leading to later struggles for independence. The Scientific Revolution in the 17th century and the Industrial Revolution in the 18th–19th centuries promoted major innovations in transport, such as the railway and automobile; energy development, such as coal and electricity; and government, such as representative democracy and Communism. With the advent of the Information Age at the end of the 20th century, modern humans live in a world that has become increasingly globalized and interconnected. As of 2010, almost 2 billion humans are able to communicate with each other via the Internet,[40] and 3.3 billion by mobile phone subscriptions.[41] Although interconnection between humans has encouraged the growth of science, art, discussion, and technology, it has also led to culture clashes and the development and use of weapons of mass destruction. Human civilization has led to environmental destruction and pollution, producing an ongoing mass extinction of other forms of life called the holocene extinction event,[42] that may be further accelerated by global warming in the future

Habitat and population

Further information: Human migration, Demography, and World population See also: City, Town, Nomad, Camping, Farm, House, Watercraft, Infrastructure, Architecture, Building, and Engineering Humans often live in family-based social structures and create artificial shelter. Early human settlements, were dependent on proximity to water and, depending on the lifestyle, other natural resources used for subsistence, such as populations of animal prey for hunting and arable land for growing crops and grazing livestock. But humans have a great capacity for altering their habitats by means of technology; through irrigation, urban planning, construction, transport, manufacturing goods, deforestation and desertification. Deliberate habitat alteration is often done with the goals of increasing material wealth, increasing thermal comfort, improving the amount of food available, improving aesthetics, or improving ease of access to resources or other human settlements. With the advent of large-scale trade and transport infrastructure, proximity to these resources has become unnecessary, and in many places, these factors are no longer a driving force behind the growth and decline of a population. Nonetheless, the manner in which a habitat is altered is often a major determinant in population change. Technology has allowed humans to colonize all of the continents and adapt to virtually all climates. Within the last century, humans have explored Antarctica, the ocean depths, and outer space, although large-scale colonization of these environments is not yet feasible. With a population of over six billion, humans are among the most numerous of the large mammals. Most humans (61%) live in Asia. The remainder live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%). Human habitation within closed ecological systems in hostile environments, such as Antarctica and outer space, is expensive, typically limited in duration, and restricted to scientific, military, or industrial expeditions. Life in space has been very sporadic, with no more than thirteen humans in space at any given time. Between 1969 and 1972, two humans at a time spent brief intervals on the Moon. As of March 2011, no other celestial body has been visited by humans, although there has been a continuous human presence in space since the launch of the initial crew to inhabit the International Space Station on October 31, 2000. However, other celestial bodies have been visited by human-made objects. Since 1800, the human population has increased from one billion to over six billion.[44] In 2004, some 2.5 billion out of 6.3 billion people (39.7%) lived in urban areas, and this percentage is expected to continue to rise throughout the 21st century. In February 2008, the U.N. estimated that half the world's population will live in urban areas by the end of the year.[45] Problems for humans living in cities include various forms of pollution and crime,[46] especially in inner city and suburban slums. Humans have had a dramatic effect on the environment. As humans are rarely preyed upon, they have been described as superpredators.[47] Currently, through land development, combustion of fossil fuels and pollution, humans are thought to be the main contributor to global climate change.[48] Human activity is believed to be a major contributor to the ongoing Holocene extinction event, which is a form of mass extinction. If this continues at its current rate it is predicted that it will wipe out half of all species over the next century

A STORY OF CLEAVER FOX

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campus LIFE

Campus Lifestyle..

Student Affairs..

All activity related to extracurricular programs, forums, clubs, community service, and entrepreneurship cell and students council are managed by the student affairs department. Counselors are available to guide students and share personal issues

Housing & Dining..

The student accommodation at SRM is a "home away from home". There are separate hostels for men and women on the campus, with all facilities for study and recreation. Besides hostel dining facility, there are food outlets and cafes too, open 12 to 15 hours a day.

Diversity

It's a 'mini India' out here at the SRM university campus - with students from all over India and other parts of the world. The campus reflects this cosmopolitan aspect of the student community, with celebrations of regional festivals

Community Centers=

Students are initiated into community service at SRM, and are encouraged to actively participate in the many social initiatives such as Annsh - the school for drop-outs, Butterflies project - the cultural and sports forum for underprivileged children, etc

Clubs

Several clubs are active on the SRM university campus, initiated by enthusiastic students. The Robotics Club is a good example, motivating students, distributing low cost kits, conducting workshops and organizing competitions

Religious Life

There are prayer halls on campus, for all the major religions

santosh chaudhary

Chapter 1

WHAT IS LIFE

Monday, February 28, 2011

Blog Archive

About Me

Chapter2

HUMAN LIFE

Chapter3

STUDENT LIFE

Chapter4

A STORY OF CLEAVER FOX

Chapter5

campus LIFE