8TH grade HISTORY OF TOXONOMY Scientist has estimated that there are at least 8.7 million different species of living things on earth, with 6.5 million on land and 2.2 million species on the ocean. Thus, a system of classification or arranging information about these species is necessary. Taxonomy is the science of grouping organisms according to their presumed natural relationships. Classifying organisms is useful for reason such as: ease of identification giving order to a vast variety of living things ease of communication showing evolutionary relationships History of Taxonomy Classification of organisms is based on the similarities and differences among organisms in their anatomy differences and in physiology. Early classification tended to be artificial. They emphasized different life span, habitat, leaf shape flower color. More than 2000 years ago, the Greek philosopher Aristotle first classified living things as either plants or animals. Animals Plants Land dweller-horses, dogs etc. Trees - narra, mango Water dwellers-fishes shrubs-bougainvillea, roses Air dwellers-birds herbs-mayana, oregano However, due to the discovery of new on organisms, scientists realized that Aristotle’s categories did not provide information on all the variations among living things. In the eighteen century, the great Swedish botanist Carolus Linnaeus devised a system of classification known as binomial system of nomenclature. In 1753, Linnaeus his list of plant names and his animal names in 1758. Linnaeus developed a system of grouping organisms into hierarchical categories: He placed structurally similar organisms that can mate and produce fertile offspring into a group called species, similar species into a larger group called genus, and similar genera into a family. Similar families were placed in an order, similar orders in a class, and similar classes in phylum, and lastly phyla into either the plant or animal kingdom. The Linnaean system of classification is called binomial nomenclature which means "two names". The first names refer to the genus and always begin with capital letter. The species name follows and begins with a small letter. The genus name is usually a noun, and the species name, an adjective. Both names are in Latin since unchanging, and is understood by scientists from all countries. In 1990, American microbiologist and biophysicist Carl Woese, devised a system of classification called the three-domain system of taxonomy. Kingdom Monera was divided into two kingdoms: Eubacteria and Archaebacteria A domain is the highest taxonomic rank of organisms in the three-domain system of taxonomy consists of three domains: Archaea, which includes Bacteria, and Eukarya. The first two are all prokaryotic microorganisms, or single-celled organisms whose cells have no nucleus. Eukarya includes all multicellular organisms that has a nucleus and membrane-bound organelles. DOMAIN Eukarya: Organisms that has a nucleus and a membrane bound organelles KINGDOM Animalia: Many-celled organisms that must consume organic substances; heterotrophs PHYLUM Chordata: With notochord, nerve cord, gills, tail, and muscle CLASS Mammalia: Young nourished by milk, animals have hair or fur and warm blood ORDER Primates: Live on trees FAMILY Hominidae: Upright animals with bipedal locomotion; color and binocular vision GENUS Homo: Upright with large brain; parental care of young SPECIES sapiens: Sparse body hair; high forehead; sophisticated cultural evolution Scientific name: Homo sapiens Common name: Man Common Names Every living organism on earth is classified and named by a set of rules. Those rules are used by all scientists around the planet. The names of organisms are called scientific names, not common names. Common names are the ones you might use when talking with your friends. You call your pet a dog or a cat, that's the common names but, scientists call those animals by a set of several names for instance, like Canis familiaris for a dog. COMMON NAME SCIENTIFIC NAME A. Plants Onion Allium cepa Potato Solanum tuberosum Tomato Solanum lycopersicon Mango Mangifera indica Cucumber Cucumis sativus B. Animals Cat Felis catus Asian bullfrog Rana tigrina Cobra Naja naja Chicken Galus galus Domestic Pig Sus scrofa domesticus The Basis of Classification Over the years, there have been different ways of grouping the living things on earth. Some scientists have used the Phenetic System that uses phenotypic similarities or physical characteristics. Phenotypic means "physical." Scientists compared what animals looked like, not their genetics. Scientists also grouped the organisms according to their similarities. For example, a dolphin could be more like a fish than you, because they swim and have fins. But, in reality, they are mammals and have more similarities to you than to any fish. Taxonomists have considered other characteristics in classifying organisms. They compare the embryology, biochemical similarity, and genetic similarity. At the level of the larger categories, the embryological features are often used in classification. The wings of birds and wings of insects are analogous but not homologous since they arise from different tissues in the embryo. Consequently, they are not closely related. However dissimilar animals with embryologically similar parts may share a similar evolutionary history Scientists also used a Cladistic System when they use phylogenic similarities. The phylogenic system uses evolutionary similarities to group organisms. So, birds might be related to dinosaurs, which are reptiles, because scientists think that birds evolved from early dinosaurs. On the basis of the above characteristics, taxonomists are able to infer the probable evolutionary relationship among species. Taxonomists illustrate the inferred phylogeny of related organisms with a diagram called phylogenetic tree. THREE DOMAIN There are three domains of the living things in this world 1. Archaea Archaea domain is one of the groups of single-celled prokaryotic organisms which have different molecular characteristic that separates them from bacteria. Archaea comes from the Greek word "archaios", meaning ancient or primitive. Members of the archaea, Pyrolobus fumarii, can survive on temperature to live at 113℃ (235℉). they are found living in hydrothermal vents. Picrophilus species was isolated from acidic soils in Japan and is the most acid-tolerant organisms known, they are able to grow around pH 0. Methanogens, which produce methane gas as a metabolic by product are found in anaerobic environments such as marshes, hot water, and animals, including humans. 2. Eubacteria Eubacteria is also known as bacteria. The term is derived from bacterial meaning rods. The bacteria was found in the year 1674 by the Dutch scientist Anton Van Leuwenhoek who was the inventor of the also a single-lens microscope. The term bacteria was introduced by Ehrenberg in 1828. The study of bacteria is known as bacteriology. Characteristic Of Eubacteria Generally has no chlorophyll Varied forms Parasitic and pathogenic Unicellular does not have (single-celled)membrane core or prokaryote Sized between 1 to 5 microns 3. Eukarya Eukarya is the domain of the unicellular and multicellular organisms who have membrane core (eukaryotic). These are that organisms contain nucleus as well as membrane-bound organelles in their cells. The Domain Eukarya includes the kingdom Protista, fungi, Plantae, and Animalia. The Kingdom Protista: protists are grouped into plant-like protists, and animal-like protists The Kingdom Plantae: grouped into Bryophyte (moss), Pteridophyta (non flowering), and Spermatophyta (flowering plants) The Kingdom Fungi: are grouped into Ascomycota, Basidiomycota, Zygomycota, and Deutromycota The Kingdom Animalia: are grouped into Invertebrates and Vertebrates THE FOUR KINGDOM EUKARYA 1. Kingdom Protista includes all eukaryotic organisms which lack tissue formation. There are more than 50, 000 species of protists. Characteristics Most are microscopic. Most are single celled. Some can perform photosynthesis making them autotrophs. Some are heterotrophs. They can produce asexually (by themselves) or sexually (exchanging genetic material with partners). Some of them can move by means of cilia, flagella, or pseudopodia. Three Types of Protist They are put into the protist group because they don't fit into any of the other groups. a. Plant-like b. Animal-like c. Fungus-like a. Plant-like protists They get their energy by making their own food through photosynthesis using light energy. Examples of plant-like protists are Diatoms Algae Dinoflagellate Euglenoids Plant-like protists impact on Earth: Algae are good because it makes products such as toothpaste, yogurt, and marshmallows. It removes pollution from the water. Algae is bad because it releases toxins that can kill fish. b. Animal-like protists They can sometimes get their energy by taking in food (eating). Examples of animal-like protists: i. Ciliates-move by using tiny hairs called cilia - e.g. Paramecium ii. Flagellates-move by using whip-like tails called flagella ., e.g. Euglena iii. Pseudopods - move by using pseudopods e.g. Amoeba Animal-like protists impact on Mother Earth: i. Protozoans are good because they break down dead organisms ii. Protozoans are bad because they can cause diseases. c. Fungus-like protists They get their energy by throwing up on their food and then slurping it up with tiny mouths. Examples of fungus-like protists: Slime molds Fungal-like protists impact on Earth: • Slime molds are bad because they destroy plants and crops. • Slime molds are good because they break down dead animal matter. 2. Kingdom Fungi includes all eukaryotic organisms the fungi kingdom represents those organisms, and over 70,000 other species of fungus. Most fungi have the following characteristics: • Most are multicellular, but yeast are a unicellular exception. • Most are heterotrophs and many are saprophytes. • Their cells have cell walls made of chitin. • They can reproduce sexually or asexually through spores. Since fungi are heterotrophs, they need to eat other things to survive. This is one of the things that distinguish them from plants, even though many plants and fungi are both immobile organisms stuck in the ground like a flagpole. Some fungi are saprophytes. They can eat or decompose dead organic matter. For this reason, they are the decomposers of the forest floor. Many species of fungi get their nutrients through structures called hyphae. These are root-like tubes that grow into whatever the fungi attached to. They digest food outside of these hyphae, and then absorb it through the hyphae. Most fungal cell walls are composed of the polymer derivate of glucose called chitin. The fungal life cycle differs from species to species. Fungi can reproduce by snapping off a piece of their hyphae, producing a bud, separating cells by a septa-like structure, or producing spores. Spores are these tiny little cells that can turn into a brand new mushroom, the cap-like reproductive structure that looks like a tiny parasol. Meanwhile the fungal hyphae grow into the ground. The spores are produced by mitosis, so they are identical to its parent. Most mating cycles are asexual. However, in sexual reproduction. spores from two different organisms can fuse nuclei. These spores can then undergo meiosis to form four haploid cells with different genetic material, a mix of mom and pop. 3. Kingdom Plantae The third eukaryotic kingdom is Plantae. Plants are multicellular, have cell walls. obtain energy through photosynthesis. It is divided into different types. There are bryophyte that includes mosses; seedless vascular plants that includes ferns; gymnosperms that include Christmas trees, and angiosperms that include all the flowers on earth. Plant Characteristics: 1. They are multicellular. 2. They are autotrophs. 3. Plant cells have cell walls made of cellulose. 4. Plant cells have chloroplasts that perform photosynthesis. 5. They alternate generations. Plants are green due to a pigment called chlorophyll in their chloroplasts, the organelles that perform photosynthesis. Because they perform photosynthesis, all plants are autotrophs that make their own food. The cell walls of plants are largely made up of cellulose, a different sugar polymer than the chitin, that makes up fungal cell walls. Cellulose is a compound that is strong like a bull. It gives plant cells. Therefore the entire plant has the strength to carry the weight of heavy branches, leaves, and 1,000 migrating birds. It also gives plants a defined, rigid shape. Plant reproduction can also be a little variable, but they share the common feature of alternating generations. One generation is known as the sporophyte generation, and these family members produce a reproductive spore. These spores can create new plants in some species that are genetically identical to their parents, just like the fungal spores did. On the other hand, the plant that arises out of a spore will be part of the gametophyte generation, and usually doesn't look much like its parent at all. This plant will produce gametes through meiosis (eggs or sperm) that need to fuse with another gamete to produce the next plant. These gametophyte-producing organisms are tinier-like what you'd find if you cracked open a pinecone or looked under a fern. 4. Kingdom Animalia is composed of Invertebrates (without backbones) and vertebrates (with backbones), multicellular, no cell walls, and obtain energy through respiration. Characteristics: 1. They are multicellular. 2. They are heterotrophs. 3. They do not have cell walls. 4. Embryonic development involves a blastula. Of these distinguishing characteristics, the term blastula probably caught your eye as a newbie. After an egg and sperm combine, the new organism forms a bastula in early embryonic development (when making a bebe). A blastula is a sphere of hollow middle region-like a chocolate-covered cherry without cherry. All animals go through this blastula-stage, but no other organism does. There's a difference in what happens during this blastula stage, though. After animals form a blastula, cells move inwards towards this fluid space. This create an opening called a blastopore. In protostomes, this blastopore later develops into the animal mouth. In deuterostomes, this blastopore develops into the anus, with a mouth developing on the opposite side. A cross section of a blastula is a hollow sphere of cells. All animals evolved from one common ancestor, likely some sort of protist. The different types of animals and their phyla have been organized for you in this helpful little table. Invertebrates Invertebrates are animals that do not have backbones. 97 % of the animal kingdom is made up of invertebrates. Some can be found in ponds, oceans, and other water environments. Insects and some other invertebrates have exoskeletons. An exoskeleton is a hard outer covering that protects an animal's body and gives it support. Groups of Invertebrates Phylum Porifera (Sponges) They look like plants but they are animals. Sponges stay fixed in one place. Their bodies are full of holes and their skeleton is made of spiky fibers. Water flows through the holes of their body which enables them to catch food. Examples: corals, hydras, and jellyfish. Characteristics: • Corals look like plants but they belong to the animal kingdom. • They have soft tube-like bodies with a single opening surrounded by arm like parts called tentacles. • They feed by catching tiny animals in their tentacles. • Hydras have tentacles that catch their food. • They move from place to place. • Hydras are much smaller animals. • Jellyfish catch shrimp, fish, and other animals in its tentacles. Worms: Flatworms , Roundworms, and Segmented worms Characteristics • Worms are tube-shaped invertebrates which allow them to be put into groups. They can be found in both land and water environments Phylum Platy helminthes (Flatworms) • They have a head and a tail, and flattened bodies. • A tapeworm is a flatworm that can live inside the body of animals and humans. It can cause you to become sick. Phylum Nematoda (Roundworm) • They have rounded bodies. • They live in damp places and they can also live inside humans and other animals. • They too can make people and other animals sick. Phylum Annelida (Segmented worms) • The earthworm belongs to this group of worms. • Their bodies are divided in segments, or sections. • They prefer burrowing through moist soil. • This allows them to move easily and it keeps them from drying out. Phylum Cnidaria (Starfish and Sea Urchins) Characteristics: It belongs to a group of invertebrates that have tiny tube feet and body parts arranged around a central area. A starfish has five arms and no head. The hard, spiny covering of the starfish gives the animal protection. A sea urchin belongs to this same group. ? Its body is covered with spines. Phylum Mollusca Characteristics: • A mollusk has a hard shell, a rough tongue, and a muscular foot. • A snail is a mollusk with a single hard shell. • A clam has two shells joined together by a hinge. • Squids and octopuses are also mollusk. • Their hard shells are small, but they are inside their bodies. Phylum Arthropoda Characteristics: • Arthropods are a group of invertebrates with jointed legs and hard exoskeleton that protect the arthropod. • As it grows, it molts, or sheds its old exoskeleton. • Then it grows a new exoskeleton that allows its body to continue to grow. • A lobster is an arthropod. • The largest group of arthropods are insects. Arthropods: Insects, Spiders, and Centipedes/Millipedes • They are the only invertebrates that can fly. • Insects have bodies divided into three parts, and six legs. • Spiders have jointed legs (eight legs), jaws and fangs. • Centipedes and millipedes are also arthropods. • Centipedes uses its many legs to run from enemies. • Millipedes roll up their bodies when they sense danger approaching. Animal Phylum Common Name Examples A sampling of Characteristic Porifera Sponges Sponges Tissue layers or nervous system, hard endoskeleton Cnidarians Jellyfish, sea anemones, the Great Coral Reef Tissues and symmetry, asexual and sexual production Flatworms Flukes and undesirable tapeworm Tissues, bilateral symmetry, asexual and sexual production Wriggly worms Tissues, bilateral symmetry, protostomes, slimy skin allows gas exchange Snail, squid, oyster Tissues, bilateral symmetry, protostomes, most with exoskeleton shells Cnidaria Platyhelminthes Annelida Mollusca Segmented worms Mollusks Animal Phylum Examples A sampling of Characteristic Roundworms Sign Tissues, bilateral symmetry, protostomes, a worm with more brainlike cells Arthropoda Arthropods Insects, the itsy, bitsy spider, lobster, crabs Tissues, bilateral symmetry, protostomes and exoskeletons composed of chitin Echinodermata Echinoderms Starfish and see cucumber Tissues, bilateral symmetry, hard endoskeletons, deuterostomes Chordata Chordates Fishes, birds, amphibians reptile Tissues, bilateral symmetry, deuterostomes, Notochords Nematoda Common Name Vertebrae (Animals with Backbone) • Animals with backbones are called vertebrates. • Vertebrates include many different kinds of animals. They can be found just about everywhere - in oceans, rivers, forests, mountains, and deserts. • Animals with backbones can be broken up into smaller groups by characteristics. Fish Characteristics: • They are the largest group of vertebrates. • They come in many sizes and shapes. • Many fish are covered with scales that protects them. • They have fins that help them to steer and balance in the water. • Their body temperatures vary in the water. . They breathe through gills. Amphibians Characteristics: • Their body temperature varies with their surroundings. • Amphibians hatch from eggs and they can live on land as an adult. • Young amphibians breathe through gills like fish. • Adult amphibians breathe air from lungs. ? Some have smooth moist skin. Reptiles Characteristics: • Reptiles can move at various speeds. They lay their eggs on land. . They have dry scaly skin. • They can include animals as large as a crocodile. • Their body temperature varies with their environment. • They live in hot, dry deserts and in warm, wet tropical rain forests. Birds Characteristics: • Birds lay hard shelled eggs that hatch in their nest. • There are about 9,000 types of birds. • Birds are vertebrates that have wings and they are covered with feathers. No other animal has this feature. • The bird's skeleton is very light in weight. This helps them to fly. • Birds range in size from as small as your finger or as large as a human. Mammals Characteristics: • They include a wide range of animals: ape, lions, kangaroos, bats, and etc. • Their young grows inside the mother. • Humans are mammals but they (animals) have more hair than we do. • The hair keeps the animals warm. . • They feed milk to their young. Body Temperature Heart Chamber Outer Cover Resp. 2 and Co2 Fer. Site Embryo Development Young Care Fish Cold 2 Scale Gills Externalin-water In water soft eggs None usually Amphibian Cold (ectothermic) 3 Most skin with mucous Skin and lungs External in water In water eggs None Dry skin with scales Lungs Internal External leathery egg hatch None usually Skin with feathers Lungs Internal Internal Parents Internal Parents long term Reptile Cold 3 except alligators and crocs 4 Bird Warm 4 Mammal Warm 4 Skin Lungs Internal BIODERVERSITY NATURE Biodiversity is the variety of life forms on earth and the essential interdependence of all living things. Most of the biodiversity is concentrated in tropical region. Distribution of biodiversity is depends on climate, altitude, and type of soil. There are three types of biodiversity 1. Diversity of Species 2. Diversity of Ecosystem 3. Diversity of Genes Biodiversity and Balance of Nature 1. Tropic Level: Elimination of species from tropic level can cause destruction of ecosystem as well as biodiversity. 2. Complex Ecosystem: In a complicated ecosystem having several tropic levels, loss of one or more spices do not cause any serious problem because the alternative is available. 3. Keystone Species: Loss or addition of species causes detectable changes in ecosystem rates i.e. species make unique contribution to ecosystem functioning. 4. Niche Complementary: Difference among species in their requirements for different resources will cause complementary interaction so that a species could obtain more resources. Benefits of Biodiversity 1. Consumptive value: Medicine Batter crop varieties Industrial Material 2. Non-Consumptive Value: Recreation Education and Research Traditional value 3. Ecological services: • Balance of nature • Regulation of climate • Degradation of waste • Cleaning of air and water • Cycling of nutrients • Control of potential pest and disease causing species • Detoxification of soil and sediments • Stabilization of land against erosion • Carbon sequestration and global climate change • Maintenance of Soil fertility Threats to biodiversity Natural causes: • Narrow geographical area • Low population • Low breeding rate • Natural disasters Habitat modification • Overexploitation of selected species Innovation by exotic species • Pollution • Hunting • Global warming and climate change Biodiversity is our life. If the Biodiversity got lost at this rate then in near future, the survival of human being will be threatened. So, it is our moral duty to conserve Biodiversity as well our Environment. Long-term maintenance of species and their management requires co-operative efforts across entire landscapes.
