Why are living organisms classified? Because it gives some semblance of order to the numerous living organisms that are in nature. It gives biologists logical groupings to make organisms easier to study, and it provides scientific names that can be used by anyone in any culture/country/reigion of the world to decrease confusion. It's mainly because biology is not an exact science like chemistry, mathematics, classical physics and such.
It is heavily influenced by interpretation of findings in a purely atheistic way. Therefore biological classification and taxonomy is done to fit with the untouchable theory of evolution. So contradictions are inevitable. The next change will come.
Some biological scientists have suggested to classify the living organism according their ability for successful interbreeding. This would give a testable basis for the kind of living organisms. But this idea was rejected because it would give some hard facts that do not support macro evolution but only micro evolution.
The history of classification. Taxonomy, the practice of classifying biodiversity, has a venerable history. Although early natural historians did not recognize that the similarities and differences among organisms were consequences of evolutionary mechanisms, they still sought a means to organize biological diversity. In 1758 Carl Linn proposed a system that has dominated classification for centuries. Linnaeus gave each species two names, denoting genus and species (such as Homo sapiens). He then grouped genera into families, families into orders, orders into classes, classes into phyla, and phyla into kingdoms. Linn identified two kingdoms: Animalia (animals) and Plantae (plants). Biologists generally accepted the idea of evolution shortly after the publication of Darwin's The Origin of Species and, since Linnaeus' classification system, they have described an immense number of species. Despite these facts, taxonomy changed little until the 1960s.
The first major break from the Linnean model came from Thomas Whittaker. In 1969 Whittaker proposed a "five kingdom" system in which three kingdoms were added to the animals and plants: Monera (bacteria), Protista, and Fungi. Whittaker defined the kingdoms by a number of special characteristics. First, he specified whether the organisms possessed a true nucleus (eukaryotic) or not (prokaryotic). Because Monera are prokaryotic and virtually all are unicellar, they are distinct from the other four eukaryotic kingdoms. With few exceptions, the eukaryotic unicellular organisms were placed into the kingdom Protista.
The three multicellular eukaryotic kingdoms distinguish themselves by the general manner in which they acquire food. Plants are autotrophs and use photosynthetic systems to capture energy from sunlight. Animals are heterotrophs and acquire nutrients by ingesting plants or other animals, and then digesting those materials. Fungi are also heterotrophs but, unlike animals, they generally break down large organic molecules in their environment by secreting enzymes. Unicellular organisms use a variety of modes of nutrition. (See the Microbial Diversity unit.)
The five kingdoms system was certainly an advance over the previous system because it better captured the diversity of life. Three groups -- bacteria, fungi, and protists - did not fit well into either the animal or plant category. Moreover, each of these three groups appeared to possess diversity comparable to that of animals or plants. Thus, the designation of each as a kingdom seemed fitting.
The 3main systems of classification.The three-domain system is a biological classification introduced by Carl Woese in that divides cellular life forms into archaea, bacteria, and eukaryote domains
List and describe the five kingdom classification system of organisms also its charecterstics of each kingdom.living organisms are subdivided into 5 major kingdoms, including the Monera, the Protista (Protoctista), the Fungi, the Plantae, and the Animalia. Every living creature on Earth belongs to a kingdom. Scientists debate how many kingdoms there are, but most agree there are five. Here is how the five kingdoms are organized.
Monera
Monera are single-celled organisms that don’t have a nucleus. Bacteria make up the entire kingdom. There are more forms of bacteria than any other organism on Earth. Some bacteria are beneficial to us, such as the ones found in yogurt. Others can cause us to get sick.
Protists
Protists are mostly single-celled organisms that have a nucleus. They usually live in water. Some protists move around, while others stay in one place. Examples of protists include some algae, paramecium, and amoeba.
Fungi
Fungi are usually motionless organisms that absorb nutrients for survival. They include mushrooms, molds, and yeasts.
Plants
Plants contain chlorophyll, a green pigment necessary for photosynthesis, a process in which plants convert energy from sunlight into food. Their cell walls are made sturdy by a material called cellulose, and they are fixed in one place. Plants are divided into two groups: flower- and fruit-producing plants and those that don’t produce flowers or fruits. They include garden flowers, agricultural crops, grasses, shrubs, ferns, mosses, and conifers.
Animals
Animals are the most complex organisms on Earth. Animals are multi-celled organisms, eat food for survival, and have nervous systems. They are divided into vertebrates and invertebrates and include mammals, amphibians, reptiles, birds and fish.
And major features as follows .. . Monera are single-celled organisms that don't have a nucleus. Bacteria make up the entire kingdom. There are more forms of bacteria than any other organism on Earth. Some bacteria are beneficial to us, such as the ones found in yogurt. Others can cause us to get sick. Protists Protists are mostly single-celled organisms that have a nucleus. They usually live in water. Some protists move around, while others stay in one place. Examples of protists include some algae, paramecium, and amoeba. Fungi Fungi are usually motionless organisms that absorb nutrients for survival. They include mushrooms, molds, and yeasts. Plants Plants contain chlorophyll, a green pigment necessary for photosynthesis, a process in which plants convert energy from sunlight into food. Their cell walls are made sturdy by a material called cellulose, and they are fixed in one place. Plants are divided into two groups: flower- and fruit-producing plants and those that don't produce flowers or fruits. They include garden flowers, agricultural crops, grasses, shrubs, ferns, mosses, and conifers. Animals Animals are the most complex organisms on Earth. Animals are multi-celled organisms, eat food for survival, and have nervous systems. They are divided into vertebrates and invertebrates and include mammals, amphibians, reptiles, birds and fish.
Hierarchy of classification.The species is the most easily recognized unit of classification. Every organism belongs to a particular species, and while species concepts can sometimes be difficult to resolve, the idea of a group of organisms belong to a group of otherwise similar-looking organisms with which it can interbreed isn’t difficult to comprehend. Above the species level, it has been traditional to recognize more inclusive groups of organisms. In the cats, we can recognize at least four genera (singular genus): Acinonyx (cheetahs), Panthera (lions, tigers, and other "big" cats), Lynx (bob-tail cats) and Felis(smaller cats). A genus is a group of species related by common descent, and the species within a genus share certain (derived) features. Proceeding up the taxonomic ladder, these genera are included in the family Felidae (all cats). The Felidae is subsequently included in the order Carnivora, consisting of other families of meat-eaters (e.g., Canidae [dogs], Ursidae [bears], and Mustelidae [weasels and otters], etc.). The order Carnivora is, in turn, placed in the class Mammalia, whose defining characteristics include hair and mammary glands. This system of classification is hierarchical, in that the taxonomic categories form groups within groups. Higher categories contain greater numbers of species, and have broader definitions. The utility of such higher levels of classification is apparent: If we know the name and classification of an organism, we automatically know a considerable amount of information about that organism and we have a system by which we can communicate new information.
The term taxon (plural taxa) refers to a taxonomic group at any level. The major taxonomic categories used in biology are:
Kingdom
Phylum or Division (for plants)
Class
Order
Family
Genus
Species
You should not concentrate too much on the ranks themselves - they are simply the entities into which we place smaller groups. There are "subs" and "supers" for every category, and several other categories that can be stuck in between these major groups. The binomial name of a species consists of a genus name and a species epithet. Thus, Panthera leo is the name for a lion.Eschscholzia californica is the name for the California poppy. In print, the genus and species names are always italicized or underlined. The genus name always begins with an upper case letter, and the species epithet with a lower case letter.
Every species of organism has one, and only one scientific name. This is extremely valuable to science because there will be no confusion when communicating to others about any species. In fact, there are International Codes of Nomenclature that preside over the application of scientific names. Common names are occasionally useful, but are more often sources of confusion.
What is the scientific name? why scientist used rather than common name and how do we write it ?A name used by scientists, especially the taxonomic name of an organism that consists of a genus name and aspecific epithet, such as Homo sapiens, the scientific name for humans.
Most plants and animals have different names from place to place. In other words, names may vary from place to place. This is the reason why Scientific names are given for recognition of these plants and animals. Otherwise it would be difficult to identify each one of them from different places.
Just imagine if each place call a certain animal a name and on the other place a group of people may call the animal another name. How in the world will it be recognized easily. It would really creat a confusion and more than that, it would create so many names even if it refers to only a single animal.
The Latin language is the one used for scientific names. This is because this language was use centuries ago by learned people. If we try to disect the scientific names, it is actually divided into two parts.
The first part is the Generic Name. This usually describes a group of living things which are related. Whil the second name is the specific name that applies to the living thing.
The specific name may describe the living thing. It could also include the name of the person who discovered it. Like for example, a human being is called "Homo Sapiens", which means thinking man.. A fossil form of Homo, or man, is "Homo Sabilis' which means tool using man.and additionally We use binomials for organisms for 3 primary reasons:
1. Comon names are not the same from one place to the next (What's the difference between a crawdad and a crayfish? What's the Japanese name for a pine tree?)
2. Common names are not descriptive (What's a horsefly? How manykinds of mosses are there?)
3. A non-spoken language like Latin wil not change over time
A scientific name leaves no mistake about what organism we are talking about.
How to Write a Scientific Name
The system of nomenclature used today is based on the binomial system of nomenclature, developed by Linnaeus in the late 1700's. The binomial system of nomenclature is structured so that the scientific name of a plant consists of two names: (1) the genus or generic name, and (2) the specific epithet or species name. There are rules to follow when writing a scientific name.
Genus Name
- The genus name is written first.
- The genus name is always underlined or italicized.
- The first letter of the genus name is always capitalized.
Example: Sansevieria or Sansevieria
Specific Epithet
- The specific epithet is written second.
- The specific epithet is always underlined or italicized.
- The first letter of the specific epithet name is nevercapitalized.
Example: trifasciata or trifasciata
Scientific Name
The scientific name of this plant would appear as follows:
Sansevieriatrifasciata or Sansevieria trifasciata
What About Mutations?
The evolution of plant life is based on mutations, which are constantly occurring. Very often a particular individual of a species will mutate to a different color, size, or growth habit. These characteristics are passed on to its progeny (offspring). When this happens, a population of pants exists with the same scientific name, but a sub-group exhibits different characteristics. If the mutated group is significantly different from the parents and is stable (the traits are passed on from generation to generation), then this new group of plants is often assigned a variety name.
Variety Names
- Variety names are given when the mutation occurs in nature.
Examples: a mutation occurs in a tropical rain forest
- The abbreviation var. is used to signify that the mutation is a variety. var. is placed after the specific epithet and is notunderlined or italicized.
Example: Sansevieria trifasciata var.
- The variety name is written after var.
- Capitalize the first letter of the variety name only if it is a proper noun.
- Underline or italicize the variety name.
Example: Sansevieria trifasciata var. Laurentii orSansevieria trifasciata var. Laurentii
Mutations can also occur because of human interventions such as breeding, applying mutagens, propagation, or by cultural practices. In these cases, the new group of mutated plants is called a cultivar. "Cultivar" is an abbreviated form of cultivated variety. The mutated plants are assigned a cultivar name.
Cultivar Names
- Cultivar names are given when the mutation occurs due to human influence.
Examples: a mutation occurs in a garden
- The abreviation cv. is used to signify that the mutation is a cultivar. cv. is placed after the specific epithet and is notunderlined or italicized.
Example: Sansevieria trifasciata cv.
or single quotes are used instead of cv.
Example: Sansevieria trifasciata 'Name'
- The cultivar name is written after cv. or within the single quotes.
- Capitalize the cultivar name.
- Never underline or italicize the cultivar name.
Example: Sansevieria trifasciata cv. Golden Hahnii or
Sansevieria trifasciata 'Golden Hahnii'
