Taxonomy
Taxonomy.
This Module contains the following topics.
Biology.
Branches of Biology.
Bio-diversity.
Taxonomy.
History of taxonomy.
Charaka.
Aristotle.
Corolous Linnaeus.
Hierarchy of biological classification.
Seven levels of biological organisation.
Kingdom.
Animalia.
Plantae.
Fungi.
Protozoa.
Monera.
Phylum.
Class.
Order.
Family.
Genus.
Species.
Systematic position of Humans.
Systematic position of Mango.
Binominal Nomenclature.
Biology.
The word Biology, is derived from the word Bios, which means life.
Biology is a natural science, concerned with study of life, and living organisms.
In general, Biology recognises cells as, the basic unit of life.
It considers, genes as the basic unit, of hereditary.
It recognises evolution as, the engine that propels the synthesis, and creation of new species.
Branches of Biology.
Biology is a vast science.
It is the science of life itself.
There are many specialised branches in biology.
Botany is study of plants.
Agriculture, is the science of producing, crops and raising live stock.
Ecology, is the study of interaction of living organisms, with one and another, and their environment.
Evolutionary biology, is the study of origin and descent of species over time.
Genetics, is the study of genes and hereditary.
Microbiology, is the study of microscopic organisms.
Molecular biology, is the study of biological functions at the molecular level.
Palaeontology, is the study of fossils in prehistoric life.
Physiology, is the study of the functioning of living organisms and organs.
Zoology, is the study of animals.
Anatomy, is the study of formal function in plants and animals, including human beings.
Cytology, is the study of cell.
Morphology, is the study, of form and structure of organisms, and their internal organs.
Histology, is the study of tissues.
Biochemistry, is the study, of chemical reaction, required for life.
Bioengineering, is the study of Biology, through engineering.
Bioinformatics, is the use of information technology, for biological data.
Biomechanics, is the study, of the mechanics of living beings.
Biophysics, is the study of biological process, by applying plain theories of physics.
Biotechnology, is the study, of manipulating living matter, including genetic modification.
These are some examples, of the interesting branches of biology.
Though, there are many branches in biology, all of them, in essence, is a study of life.
The branches help to view life, from a particular perspective.
The branches also help, to specialise, in a particular area, of biology.
You might have noticed that, many branches, are inter disciplinary.
It is fascinating to know, that there is physics, chemistry and engineering in biology.
It is however, important to remember, that the sum total of all branches, is the science of life.
Bio-diversity.
There is a large number, and variety of living organisms.
We know of animals, like cows, goats and sheep.
We also know animals, like tigers and lions.
We know of trees, like banana trees, mango trees, and guava trees.
We know of plants, like rose plant, tulsi plant, jasmine plant, rice plant, and sugar cane plant.
We know of aquatic animals, like gold fish, silver fish, and sharks.
We know of insects, like ants, flies, and mosquitoes.
We also know creatures, like spiders, and worms.
We know of birds, like crows, parrots, pigeons and eagles.
We know of the existence of bacteria, but we cannot see it.
Good Bacteria is present, in curds, bread and cakes.
Some types of viruses, causes us to be ill.
So, life in general, comprises of, a very wide variety of, living organisms.
The examples, we discussed, are just a very few, of the millions of species, that exists in nature.
But we would have noticed that, as we discuss the examples, we intuitively grouped these organisms.
When there is large number of things, like living organisms, it is natural to group them.
For examples, cows, goats and sheep, belong to a group.
Crows, parrots, pigeons and eagles, also are a group, but a different group.
Ants, flies, and mosquitoes are also a group, but a different group.
Grouping is usually done, based on similar characteristics.
Fish live in water.
Animals live on land.
Birds can fly.
Living organism have been grouped, based on similar characteristics.
This has being happening throughout, the history of biological science.
Taxonomy.
The science of classification, of biological organisms, on the basis of similar characteristics, is called taxonomy.
Taxonomy, is one of the branches of biology.
There are more than, 1.9 million species, of living organisms in our planet, that have been identified.
Scientists are, still identifying more species.
There are possibly, millions of species, which are still to be identified.
We can imagine the huge task, of classifying 1.9 million organisms.
That is why taxonomy itself, is a branch of biological science.
The science of taxonomy, itself is evolving.
As we advance, more and more in biological science, our taxonomy is getting, more sophisticated and precise.
This is all the more so, with the recent exiting discoveries, in genetics.
Taxonomy helps us, to identify, remember and study, groups of organisms.
It helps understand relationships, between groups of organisms.
Taxonomy also helps to understand, the evolution of organisms, from simple forms to complex forms.
History of taxonomy.
Charaka.
Charaka was the ancient Indian sage.
He was a philosopher, astronomer, and physician.
He classified 340 plant types and about 200, animal types.
This is not bad, considering, he did it in 600 BC.
This was a good beginning, for classifying 1.9 million living organisms.
Charaka, is considered as an authority, in ayruveda.
Ayruveda, is a science of traditional medicine, in India.
Charaka, is known as father of Ayruveda.
Aristotle.
Aristotle, was a great Greek philosopher and biologist.
His writings cover many subjects, like physics, biology, logic, music and politics.
He dissected many animals, to study their structure.
Based on this, he classified some type, of plants and some type of animals.
His classification, was very elementary.
For example, animals were classified as.
- Aquatic animals, found in water.
- Terrestrial animals, found in land.
- Aerial animals, found in air.
Aristotle, for his contributions is known as, the father of biology.
Corolous Linnaeus.
Linnaeus, was a Swedish biologist, who lived in the 18th century.
He classified 1000's of species, of animals and plants.
He divided life, into two kingdoms.
Kingdom plantae, kingdom of plants.
Kingdom animalia, kingdom of animals.
Linnaeus, was the first person, to biologically classify human beings.
He placed, humans and monkeys under the same group, called primates.
He introduced, a hierarchy of classification.
He also introduced, the binomial nomenclature, for naming species.
He is called as, father of modern taxonomy.
Hierarchy of biological classification.
When there is large number of things to identify, hierarchical classification helps us to identify, an element of it.
To take a simple example, let us take an address of a person.
We say name, house number, street, area, city, state, country.
We know that there a number of houses in a street.
Number of streets in an area.
Number of areas in a city.
Number of cities in a state.
Number of states in a country.
With these seven levels of identification, we can identify, any one of the billions of people, in the planet.
A similar concept, is used in biology, to identify millions of species.
However, there is one important difference.
In Biology, we do not identify a individual plant, animal or organism.
Biology, we identify the species, of the organisms.
For example, all the billions of human beings, belong to one species. The Homo sapien species.
All horses belong to the species, Equus Caballus.
Seven levels of biological organisation.
The 7 levels of organisation, is a common way, of organising biological life.
The first level, is the kingdom.
A commonly used system is a, five kingdom organisation.
1. Animalia.
2. Plantae.
3. Fungi.
4. Protozoa.
5. Monera.
1. Animalia.
This includes all animals, like birds, mammals, fish, reptiles, crabs, worms and human beings.
There are about, 1.4 million species, of non insect animals.
All animals are heterotrophs.
A heterotroph, cannot produce its own food.
It is dependent, on plants and other animals for its food.
Animals are motile.
They have the ability to move around.
Animals breathe in oxygen and breathe out carbon dioxide.
Most animals, have Eukaryotic cells.
Eukaryotic cells, have a nucleus.
2. Plantae.
This includes all kinds of, plants and trees.
There are about 320000 species of plants.
Plants can produce their own food.
They use light energy from the sun, and carbon dioxide from the atmosphere.
They also use nutrients, from the soil.
They produce carbohydrates, fats and proteins.
This process is called, photosynthesis.
This food is consumed, by animals or heterotrophs.
They give out oxygen in the process.
This oxygen is breathed in by animals.
So, in nature, plants and animals, are closely related.
Most plants, have Eukaryotic cells.
Eukaryotic cells, have a nucleus.
3. Fungi.
This includes organisms, like mushrooms, and microorganisms like yeast.
4. Protozoa.
Members of this kingdom are called as Protoists.
Algae, a form of sea weed belong to this kingdom.
5. Monera.
This kingdom comprises of microorganisms, like bacteria.
This kingdom, contains mostly unicellular organisms, called prokaryotes.
Prokaryotes, are organisms, without a nucleus.
Prokaryotes have D N A, but there are in the nucleoid.
Phylum.
The second level is the phylum.
Phylum, is a division of a kingdom.
Example.
It includes, chordates and arthropods.
Chordates, are animals with an internal skeleton.
Arthropods, are animals with an external skeleton.
Class.
The third level is class.
Class, is a division of phylum.
Example.
In the chordate phylum, mammals and birds are classes.
There are about 3500 mammals.
There are about 10000 types of birds.
Order.
Fourth level is order.
Order, is division of a class.
Example.
In the mammal’s class, rodents, and primates are orders.
Family.
Fifth level is family.
A family is a division, of an order.
Example.
In the primate order, Hominids and hylobatids are families.
Genus.
Sixth level is genus.
A genus is a division, of family.
Example.
Hominids family includes, homo and pan genus.
The genus, Homo, are humans.
The genus, Pan, are chimpanzees.
Species.
Seventh level is species.
Species is a division, of genus.
Example.
Homo sapien is a species of the genus Homo.
We human beings are Homo sapiens.
To summarise, the seven levels, we can use a mnemonic.
King Philip Came Over For Green Sugar.
First letter in each word stands for a level.
Level 1. King - K is for Kingdom.
Level 2. Philip - P is for Phylum.
Level 3. Came - C is for Class.
Level 4. Over - O is for Order.
Level 5. For - F is for Family.
Level 6. Green - G is for Genus.
Level 7. Sugar - S is for Species.
Systematic position of Humans.
We human beings belong to the kingdom. Animalia.
We belong to the phylum. Chordata.
This means, that we have an internal skeleton or backbone.
Interestingly, we share this characteristic, with about 31000 species of fish.
We belong to the class. Mammalian.
We are warm blooded.
We have mammary glands, which secretes milk, to feed the young.
Another example of a mammal, is a cow.
We belong to the order. Primata.
This order has, ten finger and ten toes.
It has eyes, in front of the head.
We also, have a collar bone.
We belong to the family, hominidae.
We walk, on two legs and have a, upright posture.
We have, a S shaped vertebrae, on back bone.
Our closest relative, in this hominidae family, is the chimpanzee.
Gorilla, orangutan, are also in our family.
We belong to the genus. Homo.
There is another genus, called Australopithecus.
We belong to the species, sapiens.
Our ancestors were called, homo erectus.
They are now extinct.
We are the only species in genus, Homo.
We are called homosapiens.
Sapient, means wise.
Hopefully, we are now, wise about biological classification, and where we human being stand in it.
Systematic position of Mango.
To illustrate, a species in the plant kingdom, we will take the example of Mango.
It belongs to the kingdom, Plantae.
It belongs to the Phylum, Magnoliophyta.
It belongs to the Class, Magnoliopsida.
It belongs to the Order, Sapindales.
It belongs to the Family, Anacardiaceae.
It belongs to the Genus, Mangifera.
It belongs to the Species, indica.
In this way, all the plants in the plant kingdom, can be classified.
Binominal Nomenclature.
This is a, scientific and unique way, of naming a species.
Biological scientist, give a unique two word name, to each identified species.
The word is usually in Latin.
This bi, or two word unique name, is the scientific name, of any species.
The first word refers, to the name of the genus.
The second word refers, to the name of the species.
Example.
Homo sapien refers to, human beings.
Binomial nomenclature will widely be used, to identify a species.
Some examples, of binomial names are.
Panthera Leo, which is lion.
Panthera tigirs, which is tiger.
Felis Catus, is a cat.
Cainis Familiarus, is a dog.
Mangifera Indica, is a Mango.
Bos Taurus is a cow.
And of course, we are homo sapiens.
There are millions of more species, of living organisms, to be discovered, and identified.
Who knows ?.
You may discover a new species.
It may be even named after you.