RVRH

Classification of life

Traditionally people divided living things into plants and animals, this was mainly based upon whether they had the ability to move or not: plants couldn’t move, animals could. Originally humans were not considered to be animals, but they treated themselves as a ‘higher’ form of life, this still survives in common use of the word “animals” which refers to non-human animals. The first known attempt of a real classification of life came from the Greek philosopher Aristotle, who classified all living organisms known at that time as either a plant or an animal. He further classified animals based on their means of transportation (air, land, or water).

The exploration of parts of the New World produced large numbers of new plants and animals that needed descriptions and classification. The old systems made it difficult to study and locate all these new specimens within a collection and often the same plants or animals were given different names because the number of specimens were too large to memorize. A system was needed that could group these specimens together so they could be found, the binomial system was developed based on morphology with groups having similar appearances. In the latter part of the 16th century and the beginning of the 17th, careful study of animals commenced, which, directed first to familiar kinds, was gradually extended until it formed a sufficient body of knowledge to serve as an anatomical basis for classification.

Linnaeus is best known for his introduction of the method still used to formulate the scientific name of every species. Before Linnaeus, long many-worded names (composed of a generic name and a differentia specifica) had been used, but as these names gave a description of the species, they were not fixed. In his Philosophia Botanica (1751) Linnaeus took every effort to improve the composition and reduce the length of the many-worded names by abolishing unnecessary rhetorics, introducing new descriptive terms and defining their meaning with an unprecedented precision. In the late 1740s Linnaeus began to use a parallel system of naming species with nomina trivialia. Nomen triviale, a trivial name, was a single- or two-word epithet placed on the margin of the page next to the many-worded “scientific” name. The only rules Linnaeus applied to them was that the trivial names should be short, unique within a given genus, and that they should not be changed. Linnaeus consistently applied nomina trivialia to the species of plants in Species Plantarum (1st edn. 1753) and to the species of animals in the 10th edition of Systema Naturae (1758). By consistently using these specific epithets, Linnaeus separated nomenclature from taxonomy. Even though the parallel use of nomina trivialia and many-worded descriptive names continued until late in the eighteenth century, it was gradually replaced by the practice of using shorter proper names combined of the generic name and the trivial name of the species. In the nineteenth century, this new practice was codified in the first Rules and Laws of Nomenclature, and the 1st edn. of Species Plantarum and the 10th edn. of Systema Naturae were chosen as starting points for the Botanical and Zoological Nomenclature respectively. This convention for naming species is referred to as binomial nomenclature. Today, nomenclature is regulated by Nomenclature Codes, which allows names divided into ranks; separately for botany and for zoology. Whereas Linnaeus classified for ease of identification, it is now generally accepted that classification should reflect the Darwinian principle of common descent.

The Fungi have long been a problematic group in the biological classification: Originally, they were treated as plants. For a short period Linnaeus had placed them in the taxon Vermes in Animalia because he was misinformed: the hyphae were said to have been worms. He later placed them back in Plantae. Copeland classified the Fungi in his Protoctista, thus partially avoiding the problem but acknowledging their special status. The problem was eventually solved by Whittaker, when he gave them their own kingdom in his five-kingdom system. As it turned out, the fungi are more closely related to animals than to plants.

As new discoveries enabled us to study cells and microorganisms, new groups of life where revealed, and the fields of cell biology and microbiology were created. These new organisms were originally described separately in Protozoa as animals and Protophyta/Thallophyta as plants, but were united by Haeckel in his kingdom Protista, later the group of prokaryotes were split of in the kingdom Monera, eventually this kingdom would be divided in two separate groups, the Bacteria and the Archaea. The ‘remaining’ protists would later be divided into smaller groups in clades in relation to more complex organisms. As the molecular biology developed, non-cellular reproducing agents were discovered, sometimes these are considered to be alive and are treated in the domain of non-cellular life named Acytota or Aphanobionta.

And thus the primary taxonomical ranks were established: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Since the 1960s a trend called cladistics has emerged, arranging taxa in an evolutionary or phylogenetic tree. If a taxon includes all the descendants of some ancestral form, it is called monophyletic, as opposed to paraphyletic. Other groups, where neither the most recent common ancestor nor all the descendants are included, are called polyphyletic.

A new formal code of nomenclature, the PhyloCode, is currently under development, intended to deal with clades rather than taxa. It is unclear, should this be implemented, how the different codes will coexist.

Origin of life

Although it cannot be pinpointed exactly, evidence suggests that life on Earth has existed for about 3.7 billion years [8].

There is no truly “standard” model for the origin of life, but most currently accepted scientific models[9] build in one way or another on the following discoveries, which are listed roughly in order of postulated emergence:

Plausible pre-biotic conditions result in the creation of the basic small molecules of life. This was demonstrated in the Miller-Urey experiment, and in the work of Sidney Fox.
Phospholipids spontaneously form lipid bilayers, the basic structure of a cell membrane.
Procedures for producing random RNA molecules can produce ribozymes, which are able to produce more of themselves under very specific conditions.
There are many different hypotheses regarding the path that might have been taken from simple organic molecules to protocells and metabolism. Many models fall into the “genes-first” category or the “metabolism-first” category, but a recent trend is the emergence of hybrid models that do not fit into either of these categories.[10]

Life

Life is a condition that distinguishes organisms from inorganic objects, i.e. non-life, and dead organisms, being manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally. In physical terms, life is an organism that feeds on negative entropy.[1][2] In more detail, according to physicists such as John Bernal, Erwin Schrodinger, Wigner, and John Avery, life is a member of the class of phenomena which are open or continuous systems able to decrease their internal entropy at the expense of substances or free energy taken in from the environment and subsequently rejected in a degraded form (see: entropy and life).[3][4]

A diverse array of living organisms can be found in the biosphere on Earth. Properties common to these organisms – plants, animals, fungi, protists, archaea and bacteria – are a carbon and water-based cellular form with complex organization and genetic information. They undergo metabolism, possess a capacity to grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment in successive generations.

An entity with the above properties is considered to be a living organism, that is an organism that is alive hence can be called a life form. However, not every definition of life considers all of these properties to be essential. For example, the capacity for descent with modification is often taken as the only essential property of life. This definition notably includes viruses, which do not qualify under narrower definitions as they are acellular and do not metabolise. Broader definitions of life may also include theoretical non-carbon-based life and other alternative biology. Some forms of artificial life, however, especially wet alife, might alternatively be classified as real life.

There is no universal definition of life; there are a variety of definitions proposed by different scientists.To define life in unequivocal terms is still a challenge for scientists[5][6].

Conventional definition: Often scientists say that life is a characteristic of organisms that exhibit the following phenomena:

Homeostasis: Regulation of the internal environment to maintain a constant state; for example, sweating to reduce temperature.
Organization: Being composed of one or more cells, which are the basic units of life.
Metabolism: Consumption of energy by converting nonliving material 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 synthesis than catalysis. A growing organism increases in size in all of its parts, rather than simply accumulating matter. The particular species begins to multiply and expand as the evolution continues to flourish.
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 when touched to complex reactions involving all the senses of higher animals. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun or an animal chasing its prey.
Reproduction: The ability to produce new organisms. Reproduction can be the division of one cell to form two new cells. Usually the term is applied to the production of a new individual (either asexually, from a single parent organism, or sexually, from at least two differing parent organisms), although strictly speaking it also describes the production of new cells in the process of growth.

Plant lifeHowever, others cite several limitations of this definition[7]. Thus, many members of several species do not reproduce, possibly because they belong to specialized sterile castes (such as ant workers), these are still considered forms of life. One could say that the property of life is inherited; hence, sterile or hybrid organisms such as the mule, liger or eunuchs are alive although they are not capable of self reproduction. However, non-reproducing organisms may still propagate through mechanisms such as kin selection.

Viruses and aberrant prion proteins are often considered replicators rather than forms of life, a distinction warranted because they cannot reproduce without very specialized substrates such as host cells or proteins, respectively. Also, the Rickettsia and Chlamydia are examples of bacteria that cannot independently fulfill many vital biochemical processes, and depend on entry, growth, and replication within the cytoplasm of eukaryotic host cells. However, most forms of life rely on foods produced by other species, or at least the specific chemistry of Earth’s environment.

Rhesus Macaques resting in the sunStill others contest such definitions of life on philosophical grounds. They offer the following as examples of life: viruses which reproduce; storms or flames which “burn”; certain computer software programs which are programmed to mutate and evolve; future software programs which may evince (even high-order) behavior; machines which can move; and some forms of proto-life consisting of metabolizing cells without the ability to reproduce.[citation needed] Still, most scientists would not call such phenomena expressive of life. Generally all seven characteristics are required for a population to be considered a life form.

The systemic definition of life is that living things are self-organizing and autopoietic (self-producing). These objects are not to be confused with dissipative structures (e.g. fire).

Variations of this definition include Stuart Kauffman’s definition of life as an autonomous agent or a multi-agent system capable of reproducing itself or themselves, and of completing at least one thermodynamic work cycle.

Marine life around a coral reefYet other definitions of life are:

Living things are systems that tend to respond to changes in their environment, and inside themselves, in such a way as to promote their own continuation.[citation needed]
Life is a characteristic of self-organizing, self-recycling systems consisting of populations of replicators that are capable of mutation, around most of which homeostatic, metabolizing organisms evolve. This definition includes worker caste ants, viruses and mules, and precludes flames. It also explains why bees can be alive and yet commit suicide in defending their hive. In this case the colony, not the individual, is the living system.
Type of organization of matter producing various interacting forms of variable complexity, whose main property is to replicate almost perfectly by using matter and energy available in their environment to which they may adapt. In this definition “almost perfectly” relates to mutations happening during replication of organisms that may have adaptive benefits.
Life is a potentially self-perpetuating open system of linked organic reactions, catalyzed simultaneously and almost isothermally by complex chemicals (enzymes) that are themselves produced by the open system.

Love

The definition of love is the subject of considerable debate, enduring speculation and thoughtful introspection. The difficulty of finding a universal definition for love is typically tackled by classifying it into types, such as passionate love, romantic love, and committed love. These types of love can often be generalized into a level of sexual attraction. In common use, love has two primary meanings, the first being an indication of adoration for another person or thing, and the second being a state of relational status. Love is an act of identifying with a person or thing, capable of even including oneself (cf. narcissism). Dictionaries tend to define love as deep affection or fondness.[1] In colloquial use, according to polled opinion, the most favored definitions of love involve altruism, selflessness, friendship, union, family, and bonding or connecting with another.[6]

Thomas Jay Oord has defined love in various scholarly publications as acting intentionally, in sympathetic response to others (including God), to promote overall well-being. Oord means for his definition to be sufficient for research in ethics, religion, and science.

The different aspects of love can be roughly illustrated by comparing their corollaries and opposites. As a general expression of positive sentiment (a stronger form of like), love is commonly contrasted with hate (or neutral apathy); as a less sexual and more mutual and “pure” form of romantic attachment, love is commonly contrasted with lust; and as an interpersonal relationship with romantic overtones, love is commonly contrasted with friendship, although other connotations of love may be applied to close friendships as well.

The very existence of love is sometimes subject to debate. Some categorically reject the notion as false or meaningless.[citation needed] Others call it a recently-invented abstraction, sometimes dating the “invention” to courtly Europe during or after the Middle Ages.[citation needed] Others maintain that love really exists, and is not an abstraction, but is undefinable, being essentially spiritual or metaphysical in nature.[citation needed] Some psychologists maintain that love is the action of lending one’s “boundary” or “self-esteem” to another.[citation needed] Others attempt to define love by applying the definition to everyday life.[citation needed]

Cultural differences make any universal definition of love difficult to establish. Expressions of love may include the love for a soul or mind, the love of laws and organizations, love for a body, love for nature, love of food, love of money, love for learning, love of power, love of fame, love for the respect of others, etc. Different people place varying degrees of importance on the kinds of love they receive. Love is essentially an abstract concept,[citation needed] easier to experience than to explain. Because of the complex and abstract nature of love, discourse on love is commonly reduced to a thought-terminating cliché, and there are a number of common proverbs regarding love, from Virgil’s “Love conquers all” to The Beatles’ “All you need is love”.

http://en.wikipedia.org/wiki/Love

Emotion

Emotion is complex, and the term has no single universally accepted definition.[1] The study of emotions is part of psychology, neuroscience, and, more recently, artificial intelligence.

According to Sloman,[2] emotions are cognitive processes. Some authors emphasize the difference between human emotions and the affective behavior of animals.

In Paul D. MacLean’s classic Triune brain model, emotions are defined as the responses of the Mammalian cortex. Emotion competes with even more instinctive responses from the Reptilian cortex and the more logical, reasoning neocortex. However, current research on the neural circuitry of emotion suggests that emotion is an essential part of human decision-making and planning, and that the famous distinction made by Descartes between reason and emotion is not as clear as it seems.[3]

Emotion is generally regarded by Western civilization as the antithesis of reason. This distinction stems from Western philosophy specifically stoic and Cartesian dualism approaches, and is reflected in common phrases like appeal to emotion or your emotions have taken over.

Emotions can be undesired either to the individual experiencing them, but also can be undesired to the other persons, groups of persons, organizations, sub-cultures, and civilisations such as Western civilization, which can be viewed as the emotion being subjected to the individual’s or someone else’s discouraging meta-emotion about the undesired emotion or can be even repressed by the meta-emotions. Thus one of the most distinctive, and perhaps challenging, facts about human beings is this potential for entanglement, or even opposition, between emotion, meta-emotion, will, and reason.

Some state that there is no empirical support for any generalization suggesting the antithesis between reason and emotion: indeed, anger or fear can often be thought of as a systematic response to observed facts. In any case, it is clear that the relation between logic and argument and emotion is one which merits careful study.

Emotion as the subject of scientific research has multiple dimensions: behavioral, physiological, subjective, and cognitive. Sloman argues that many emotions are side-effects of the operations of complex mechanisms (e.g. ‘alarm’ mechanisms) required in animals or machines with multiple motives and limited capacities and resources for coping with a changing and unpredictable world, just as ‘thrashing’ can sometimes occur as a side-effect of scheduling and memory management mechanisms required in a computer operating system for purposes other than producing thrashing. Such side effects are sometimes useful, but sometimes they are dysfunctional. Other theorists, often influenced by writings of Antonio Damasio argue that emotions themselves are necessary for any intelligent system (natural or artificial).

Psychiatrist William Glasser’s theory of the human control system states that behavior is composed of four simultaneous components: deeds, ideas, emotions, and physiological states. He asserts that we choose the idea and deed and that the associated emotions and physiological states also occur but cannot be chosen independently. He calls his construct a total behavior to distinguish it from the common concept of behavior. He uses the verbs to describe what is commonly seen as emotion. For example, he uses ‘to depress’ to describe the total behavior commonly known as depression which, to him, includes depressing ideas, actions, emotions, and physiological states. Dr. Glasser also further asserts that internal choices (conscious or unconscious) cause emotions instead of external stimuli.

According to Damasio, feeling can be viewed as the subjective experience of an emotion that arises physiologically in the brain. [4]

Many psychologists adopt the ABC model, which defines emotions in terms of three fundamental attributes: A. physiological arousal, B. behavioral expression (e.g. facial expressions), and C. conscious experience, the subjective feeling of an emotion. All three attributes are necessary for a full fledged emotional event, though the intensity of each may vary greatly.

Robert Masters makes the following distinctions between affect, feeling and emotion: “As I define them, affect is an innately structured, non-cognitive evaluative sensation that may or may not register in consciousness; feeling is affect made conscious, possessing an evaluative capacity that is not only physiologically based, but that is often also psychologically (and sometimes relationally) oriented; and emotion is psychosocially constructed, dramatized feeling.”[5]

In pop culture there are sub-cultures which cultivate the expressions of anger and rebelliousness even when they are not really angry, its members encouraging each other to express the anger by internalizing meta-gladness about it. Encouragement (i.e. meta-gladness) and discouragement (i.e. psychological repression) of selected emotions - instead of mere awareness and equal interest in all emotions - can be considered as additional source of organizational climate, family dynamics, psychodynamics, personality traits, and of mental disorders, including depression among others.

Hate

Hatred is an emotion of intense revulsion, distaste, enmity, or antipathy for a person, thing, or phenomenon, generally attributed to a desire to avoid, restrict, remove, or destroy the hated object. Hate can be based on fear of an object or past negative consequences of dealing with that object. People may feel conflicting and complicated emotions or thoughts involving hate, as in a love-hate relationship.

Often the verb “to hate” is used casually as an exaggeration to describe things one merely dislikes, such as a particular style of architecture, a certain climate, one’s job, or some particular kind of food.

“Hatred” is also used to describe feelings of prejudice, bigotry or condemnation (see shunning) against a class of people and members of that class. Racism is the most well-known example of this. The term hate crime is used to designate crimes committed out of hatred in this sense.

According to evolutionary psychologists, hate is a rational reaction to people whose interests consistently conflict with one’s own. Hate is an emotion, hence it serves the protective mode of a person. People whose behavior threatens one’s own survival interests are to be hated, while people whose behavior enhances one’s survival prospects are to be liked or even loved (as in the case of offspring and other genetic kin).

The passions of hate arise from several features of our thinking process. These include a desire to strengthen our community and to alleviate our fear. The ability to quickly separate friend from foe is essential to self-defense and safety and provides the origins of hate.[1]

Also, the feelings of hate can arise unexpectedly. If one has experienced maltreatment in the past, it is proven that one is more likely to maltreat and learn to dislike or “hate” people before they get to know the person. This is shown clearly in the pattern of people who are abused, ignored, neglected, or maltreated by their parents, and those children’s tendency to become abusive or angry.

Sayings

It hurts to love someone and not be loved in return, but what is more painful is to love someone and never find the courage to let that person know how you feel.

Maybe God wants us to meet a few wrong people before meeting the right one so that when we finally meet the right person, we will know how to be grateful for that gift.

Love is when you take away the feeling, the passion, and the romance in a relationship and find out you still care for that person.

A sad thing in life is when you meet someone who means a lot to you, only to find out in the end that it was never meant to be and you just have to let go.

The best kind of friend is the kind you can sit on a porch and swing with, never say a word, and then walk away feeling like it was the best conversation you’ve ever had.

It’s true that we don’t know what we’ve got until we lose it, but it’s also true that we don’t know what we’ve been missing until it arrives.

Giving someone all your love is never assurance that they’ll love you back!

Don’t expect love in return; just wait for it to grow in their heart but if it doesn’t, be content it grew in yours.

There are things you’d love to hear that you would never hear from the person whom you would like to hear them from, but don’t be so deaf as not to hear it from the one who says it from his heart.

Never say good-bye if you still want to try; never give up if you still feel you can go on; never say you don’t love a person anymore if you can’t let go.

Love comes to those who still hope although they’ve been disappointed to those who still believe, although they’ve been betrayed, to those who still need to love, although they’ve been hurt before, and to those who have the courage and faith to build trust again.

Don’t go for looks; they can deceive. Don’t go for wealth; even that fades away. Go for someone who makes you smile because it takes only a smile to make a dark day seem bright.

There are moments in life when you miss someone so much that you just want to pick them from your dreams and hug them for real!

Hope you dream of that special someone. Dream what you want to dream; go where you want to go; be what you want to be, because you have only one life and one chance to do all the things you want to do.

Always put yourself in others’ shoes. If you feel that it hurts you, it probably hurts the person too.

A careless word may kindle strife; a cruel word may wreck a life; a timely word may level stress; a loving word may heal and bless.

The happiest of people don’t necessarily have the best of everything; they just make the most of everything that comes along their way.

Happiness lies for those who cry, those who hurt, those who have searched, and those who have tried, for only they can appreciate the importance of people who have touched their lives.

Love begins with a smile, grows with a kiss, and ends with a tear.

The brightest future will always be based on a forgotten past, you can’t go on well in life until you let go of your past failures and heart aches.

When you were born, you were crying and everyone around you was smiling. Live your life so that when you die, you’re the one who is smiling and everyone around you is crying.