Flora is the plant life occurring in a particular region or time the occurring or indigenous—native plant life. The corresponding term for animal life is fauna. Flora and other forms of life such as fungi are collectively referred to as biota. Sometimes bacteria and fungi are referred to as flora, as in the terms gut flora or skin flora; the word "flora" comes from the Latin name of Flora, the goddess of plants and fertility in Roman mythology. The technical term "flora" is derived from a metonymy of this goddess at the end of the sixteenth century, it was first used in poetry to denote the natural vegetation of an area, but soon assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century; the distinction between vegetation and flora was first made by Jules Thurmann. Prior to this, the two terms were used indiscriminately. Plants are grouped into floras based on region, special environment, or climate.
Regions can be distinct habitats like mountain vs. flatland. Floras can mean plant life of a historic era as in fossil flora. Lastly, floras may be subdivided by special environments: Native flora; the native and indigenous flora of an area. Agricultural and horticultural flora; the plants that are deliberately grown by humans. Weed flora. Traditionally this classification was applied to plants regarded as undesirable, studied in efforts to control or eradicate them. Today the designation is less used as a classification of plant life, since it includes three different types of plants: weedy species, invasive species, native and introduced non-weedy species that are agriculturally undesirable. Many native plants considered weeds have been shown to be beneficial or necessary to various ecosystems; the flora of a particular area or time period can be documented in a publication known as a "flora". Floras may require specialist botanical knowledge to use with any effectiveness. Traditionally they are books.
Simon Paulli's Flora Danica of 1648 is the first book titled "Flora" to refer to the plant world of a certain region. It describes medicinal plants growing in Denmark; the Flora Sinensis by the Polish Jesuit Michał Boym is another early example of a book titled "Flora". However, despite its title it covered not only plants, but some animals of the region, China and India. A published flora contains diagnostic keys; these are dichotomous keys, which require the user to examine a plant, decide which one of two alternatives given best applies to the plant. Biome — a major regional group of distinctive plant and animal communities Fauna Fauna and Flora Preservation Society Herbal Horticultural flora Megaflora Pharmacopoeia The Plant List Vegetation — a general term for the plant life of a regionCategoriesFlora by continent Flora by country Flora by region eFloras — a collection of on-line floras Chilebosque — checklist of Chilean native flora Flora of NW Europe with descriptions and a quiz to test your knowledge Flora of Australia Online Flora of New Zealand Series Online
Zoology is the branch of biology that studies the animal kingdom, including the structure, evolution, classification and distribution of all animals, both living and extinct, how they interact with their ecosystems. The term is derived from Ancient Greek ζῷον, zōion, i.e. "animal" and λόγος, logos, i.e. "knowledge, study". The history of zoology traces the study of the animal kingdom from ancient to modern times. Although the concept of zoology as a single coherent field arose much the zoological sciences emerged from natural history reaching back to the biological works of Aristotle and Galen in the ancient Greco-Roman world; this ancient work was further developed in the Middle Ages by Muslim physicians and scholars such as Albertus Magnus. During the Renaissance and early modern period, zoological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Vesalius and William Harvey, who used experimentation and careful observation in physiology, naturalists such as Carl Linnaeus, Jean-Baptiste Lamarck, Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms.
Microscopy revealed the unknown world of microorganisms, laying the groundwork for cell theory. The growing importance of natural theology a response to the rise of mechanical philosophy, encouraged the growth of natural history. Over the 18th, 19th, 20th centuries, zoology became an professional scientific discipline. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, the ways this relationship depends on geography, laying the foundations for biogeography and ethology. Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species. Cell theory provided a new perspective on the fundamental basis of life; these developments, as well as the results from embryology and paleontology, were synthesized in Charles Darwin's theory of evolution by natural selection. In 1859, Darwin placed the theory of organic evolution on a new footing, by his discovery of a process by which organic evolution can occur, provided observational evidence that it had done so.
Darwin gave a new direction to morphology and physiology, by uniting them in a common biological theory: the theory of organic evolution. The result was a reconstruction of the classification of animals upon a genealogical basis, fresh investigation of the development of animals, early attempts to determine their genetic relationships; the end of the 19th century saw the fall of spontaneous generation and the rise of the germ theory of disease, though the mechanism of inheritance remained a mystery. In the early 20th century, the rediscovery of Mendel's work led to the rapid development of genetics, by the 1930s the combination of population genetics and natural selection in the modern synthesis created evolutionary biology. Cell biology studies the structural and physiological properties of cells, including their behavior and environment; this is done on both the microscopic and molecular levels, for single-celled organisms such as bacteria as well as the specialized cells in multicellular organisms such as humans.
Understanding the structure and function of cells is fundamental to all of the biological sciences. The similarities and differences between cell types are relevant to molecular biology. Anatomy considers the forms of macroscopic structures such as organs and organ systems, it focuses on how organs and organ systems work together in the bodies of humans and animals, in addition to how they work independently. Anatomy and cell biology are two studies that are related, can be categorized under "structural" studies. Physiology studies the mechanical and biochemical processes of living organisms by attempting to understand how all of the structures function as a whole; the theme of "structure to function" is central to biology. Physiological studies have traditionally been divided into plant physiology and animal physiology, but some principles of physiology are universal, no matter what particular organism is being studied. For example, what is learned about the physiology of yeast cells can apply to human cells.
The field of animal physiology extends the tools and methods of human physiology to non-human species. Physiology studies how for example nervous, endocrine and circulatory systems and interact. Evolutionary research is concerned with the origin and descent of species, as well as their change over time, includes scientists from many taxonomically oriented disciplines. For example, it involves scientists who have special training in particular organisms such as mammalogy, herpetology, or entomology, but use those organisms as systems to answer general questions about evolution. Evolutionary biology is based on paleontology, which uses the fossil record to answer questions about the mode and tempo of evolution, on the developments in areas such as population genetics and evolutionary theory. Following the development of DNA fingerprinting techniques in the late 20th century, the application of these techniques in zoology has increased the understanding of animal populations. In the 1980s, developmental biology re-entered evolutionary biology from its initial exclusion from the modern synthesis through the study of evolutionary developmental biology.
Related fields considered part of evolutionary biology are phylogenetics and taxonomy. Scientific classification in zoology, is a method by which
Australian megafauna comprises a number of large animal species in Australia defined as species with body mass estimates of greater than 45 kg or equal to or greater than 130% of the body mass of their closest living relatives. Many of these species became extinct during the Pleistocene. There are similarities between prehistoric Australian megafauna and some mythical creatures from the Aboriginal dreamtime; the cause of the extinction is an active and factionalised field of research where politics and ideology takes precedence over scientific evidence when it comes to the possible implications regarding Aboriginal people. It is hypothesised that with the arrival of early Australian Aboriginals and the use of fire to manage their environment may have contributed to the extinction of the megafauna. Increased aridity during peak glaciation may have contributed, but most of the megafauna were extinct by this time. New evidence based on accurate optically stimulated luminescence and uranium-thorium dating of megafaunal remains suggests that humans were the ultimate cause of the extinction of megafauna in Australia.
The dates derived show that all forms of megafauna on the Australian mainland became extinct in the same rapid timeframe — 46,000 years ago — the period when the earliest humans first arrived in Australia. Analysis of oxygen and carbon isotopes from teeth of megafauna indicate the regional climates at the time of extinction were similar to arid regional climates of today and that the megafauna were well adapted to arid climates; the dates derived have been interpreted as suggesting that the main mechanism for extinction was human burning of a landscape, much less fire-adapted. However, early Australian Aborigines appear to have eliminated the megafauna of Tasmania about 41,000 years ago without using fire to modify the environment there, implying that at least in this case hunting was the most important factor, it has been suggested that the vegetational changes that occurred on the mainland were a consequence, rather than a cause, of the elimination of the megafauna. This idea is supported by sediment cores from Lynch's Crater in Queensland, which indicate that fire increased in the local ecosystem about a century after the disappearance of megafaunal browsers, leading to a subsequent transition to fire-tolerant sclerophyll vegetation.
Chemical analysis of fragments of eggshells of Genyornis newtoni, a flightless bird that became extinct in Australia, from over 200 sites, revealed scorch marks consistent with cooking in human-made fires the first direct evidence of human contribution to the extinction of a species of the Australian megafauna. This was contested by another study that noted the too small dimensions for the Genyornis supposed eggs, rather, attributed them to another extinct, but much smaller bird; the real time that saw Genyornis vanish is still an open question, but this was believed as one of the best documented megafauna extinction in Australia"Imperceptive overkill". On the other hand, there is compelling evidence to suggest that the megafauna lived alongside humans for several thousand years; the question of. One of the most important advocates of human role, Tim Flannery, author of the book Future Eaters, was heavily criticized for his conclusions The term "megafauna" is applied to large animals. In Australia, megafauna were never as large as those found on other continents, so a more lenient criterion of over 40 kg is applied The red kangaroo grows up to 1.8 m tall and weighs up to 85 kg.
Females weigh up to 35 kg. Tails on both males and females can be up to 1 m long. Eastern grey kangaroos. Although a male weighs around 66 kg and stand 2 m tall, the scientific name Macropus giganteus is misleading, as the red kangaroo living in the semi-arid inland is larger; the antilopine kangaroo, sometimes called the antilopine wallaroo or the antilopine wallaby, is a species of macropod found in northern Australia at Cape York Peninsula in Queensland, the Top End of the Northern Territory, the Kimberley region of Western Australia. Can weigh as much as 47 kg and grow over 1 m long. Common wombats can reach 40 kg, they thrive in Eastern Tasmania, preferring temperate forests and highland regions. The emu The southern cassowary Goanna, being predatory lizards, are quite large or bulky, with sharp teeth and claws; the largest goanna is the perentie. Not all goannas are gargantuan though: pygmy goannas may be smaller than a man's arm. A healthy adult
An arthropod is an invertebrate animal having an exoskeleton, a segmented body, paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids and crustaceans; the term Arthropoda as proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora. Arthropods are characterized by their jointed limbs and cuticle made of chitin mineralised with calcium carbonate; the arthropod body plan consists of each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Arthopods are bilaterally symmetrical and their body possesses an external skeleton; some species have wings. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments, they have over a million described species, making up more than 80 per cent of all described living animal species, some of which, unlike most other animals, are successful in dry environments. Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab.
Arthropods' primary internal cavity is a haemocoel, which accommodates their internal organs, through which their haemolymph – analogue of blood – circulates. Like their exteriors, the internal organs of arthropods are built of repeated segments, their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, their brains are formed by fusion of the ganglia of these segments and encircle the esophagus; the respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong. Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey.
Arthropods have a wide range of chemical and mechanical sensors based on modifications of the many setae that project through their cuticles. Arthropods' methods of reproduction and development are diverse; the evolutionary ancestry of arthropods dates back to the Cambrian period. The group is regarded as monophyletic, many analyses support the placement of arthropods with cycloneuralians in a superphylum Ecdysozoa. Overall, the basal relationships of Metazoa are not yet well resolved; the relationships between various arthropod groups are still debated. Aquatic species use either external fertilization. All arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and undergo a total metamorphosis to produce the adult form; the level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions. Arthropods contribute to the human food supply both directly as food, more indirectly as pollinators of crops.
Some species are known to spread severe disease to humans and crops. The word arthropod comes from the Greek ἄρθρον árthron, "joint", πούς pous, i.e. "foot" or "leg", which together mean "jointed leg". Arthropods are invertebrates with jointed limbs; the exoskeleton or cuticles consists of a polymer of glucosamine. The cuticle of many crustaceans, beetle mites, millipedes is biomineralized with calcium carbonate. Calcification of the endosternite, an internal structure used for muscle attachments occur in some opiliones. Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80 per cent of all known living animal species; the number of species remains difficult to determine. This is due to the census modeling assumptions projected onto other regions in order to scale up from counts at specific locations applied to the whole world. A study in 1992 estimated that there were 500,000 species of animals and plants in Costa Rica alone, of which 365,000 were arthropods.
They are important members of marine, freshwater and air ecosystems, are one of only two major animal groups that have adapted to life in dry environments. One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments; the lightest insects weigh less than 25 micrograms. Some living crustaceans are much larger; the embryos of all arthropods are segmented, built from a series of repeated modules. The last common ancestor of living arthropods consisted of a series of undifferentiated segments, each with a pair of appendages that functioned as limbs. However, all known living and fossil arthropods have grouped segments into tagmata in which segments and their limbs are specialized in various ways; the three-
In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both biological features. A species' habitat is those places where it can find food, shelter and mates for reproduction; the physical factors are for example soil, range of temperature, light intensity as well as biotic factors such as the availability of food and the presence or absence of predators. Every organism has certain habitat needs for the conditions in which it will thrive, but some are tolerant of wide variations while others are specific in their requirements. A habitat is not a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, for a parasitic organism it is the body of its host, part of the host's body such as the digestive tract, or a single cell within the host's body. Habitat types include polar, temperate and tropical; the terrestrial vegetation type may be forest, grassland, semi-arid or desert. Fresh water habitats include marshes, rivers and ponds, marine habitats include salt marshes, the coast, the intertidal zone, reefs, the open sea, the sea bed, deep water and submarine vents.
Habitats change over time. This may be due to a violent event such as the eruption of a volcano, an earthquake, a tsunami, a wildfire or a change in oceanic currents. Other changes come as a direct result of human activities; the introduction of alien species can have a devastating effect on native wildlife, through increased predation, through competition for resources or through the introduction of pests and diseases to which the native species have no immunity. The word "habitat" has been in use since about 1755 and derives from the Latin habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the natural environment of an organism, the type of place in which it is natural for it to live and grow, it is similar in meaning to a biotope. The chief environmental factors affecting the distribution of living organisms are temperature, climate, soil type and light intensity, the presence or absence of all the requirements that the organism needs to sustain it. Speaking, animal communities are reliant on specific types of plant communities.
Some plants and animals are generalists, their habitat requirements are met in a wide range of locations. The small white butterfly for example is found on all the continents of the world apart from Antarctica, its larvae feed on a wide range of Brassicas and various other plant species, it thrives in any open location with diverse plant associations. The large blue butterfly is much more specific in its requirements. Disturbance is important in the creation of biodiverse habitats. In the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Wildflower meadows are sometimes created by conservationists but most of the flowering plants used are either annuals or biennials and disappear after a few years in the absence of patches of bare ground on which their seedlings can grow. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. Coastal habitats can become dominated by kelp until the seabed is disturbed by a storm and the algae swept away, or shifting sediment exposes new areas for colonisation.
Another cause of disturbance is when an area may be overwhelmed by an invasive introduced species, not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands and deserts. Within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils and vegetation types. Many of these habitats grade into each other and each one has its own typical communities of plants and animals. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities and its efficiency as a coloniser. Freshwater habitats include rivers, lakes, ponds and bogs. Although some organisms are found across most of these habitats, the majority have more specific requirements; the water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools and backwaters which provide a range of habitats.
Aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marginal plants provide important habitat for both invertebrates and vertebrates, submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution. Marine habitats include brackish water, bays, the open sea, the intertidal zone, the sea bed and deep / shallow water zones. Further variations include rock pools, sand banks, brackish lagoons and pebbly beaches, seagrass beds, all supporting their own flora and fauna; the benth
Research comprises "creative and systematic work undertaken to increase the stock of knowledge, including knowledge of humans and society, the use of this stock of knowledge to devise new applications." It is used to establish or confirm facts, reaffirm the results of previous work, solve new or existing problems, support theorems, or develop new theories. A research project may be an expansion on past work in the field. Research projects can be used to develop further knowledge on a topic, or in the example of a school research project, they can be used to further a student's research prowess to prepare them for future jobs or reports. To test the validity of instruments, procedures, or experiments, research may replicate elements of prior projects or the project as a whole; the primary purposes of basic research are documentation, interpretation, or the research and development of methods and systems for the advancement of human knowledge. Approaches to research depend on epistemologies, which vary both within and between humanities and sciences.
There are several forms of research: scientific, artistic, social, marketing, practitioner research, technological, etc. The word research is derived from the Middle French "recherche", which means "to go about seeking", the term itself being derived from the Old French term "recerchier" a compound word from "re-" + "cerchier", or "sercher", meaning'search'; the earliest recorded use of the term was in 1577. Research has been defined in a number of different ways, while there are similarities, there does not appear to be a single, all-encompassing definition, embraced by all who engage in it. One definition of research is used by the OECD, "Any creative systematic activity undertaken in order to increase the stock of knowledge, including knowledge of man and society, the use of this knowledge to devise new applications."Another definition of research is given by John W. Creswell, who states that "research is a process of steps used to collect and analyze information to increase our understanding of a topic or issue".
It consists of three steps: pose a question, collect data to answer the question, present an answer to the question. The Merriam-Webster Online Dictionary defines research in more detail as "studious inquiry or examination; this material is of a primary source character. The purpose of the original research is to produce new knowledge, rather than to present the existing knowledge in a new form. Original research can take a number of forms, depending on the discipline. In experimental work, it involves direct or indirect observation of the researched subject, e.g. in the laboratory or in the field, documents the methodology and conclusions of an experiment or set of experiments, or offers a novel interpretation of previous results. In analytical work, there are some new mathematical results produced, or a new way of approaching an existing problem. In some subjects which do not carry out experimentation or analysis of this kind, the originality is in the particular way existing understanding is changed or re-interpreted based on the outcome of the work of the researcher.
The degree of originality of the research is among major criteria for articles to be published in academic journals and established by means of peer review. Graduate students are required to perform original research as part of a dissertation. Scientific research is a systematic way of harnessing curiosity; this research provides scientific information and theories for the explanation of the nature and the properties of the world. It makes practical applications possible. Scientific research is funded by public authorities, by charitable organizations and by private groups, including many companies. Scientific research can be subdivided into different classifications according to their academic and application disciplines. Scientific research is a used criterion for judging the standing of an academic institution, but some argue that such is an inaccurate assessment of the institution, because the quality of research does not tell about the quality of teaching. Research in the humanities involves different methods such as for example hermeneutics and semiotics.
Humanities scholars do not search for the ultimate correct answer to a question, but instead, explore the issues and details that surround it. Context is always important, context can be social, political, cultural, or ethnic. An example of research in the humanities is historical research, embodied in historical method. Historians use primary sources and other evidence to systematically investigate a topic, to write histories in the form of accounts of the past. Other studies aim to examine the occurrence of behaviours in societies and communities, without looking for reasons or motivations to explain these; these studies may be qualitative or quantitative, can use a variety of approaches, such as queer theory or feminist theory. Artistic research seen as'practice-based research', can take form when creative works are considered both the research and the object of research itself, it is the debatable body of thought which offers an alternative t
The nematodes or roundworms constitute the phylum Nematoda. They are a diverse animal phylum inhabiting a broad range of environments. Taxonomically, they are classified along with insects and other moulting animals in the clade Ecdysozoa, unlike flatworms, have tubular digestive systems with openings at both ends. Nematode species can be difficult to distinguish from one another. Estimates of the number of nematode species described to date vary by author and may change over time. A 2013 survey of animal biodiversity published in the mega journal Zootaxa puts this figure at over 25,000. Estimates of the total number of extant species are subject to greater variation. A referenced article published in 1993 estimated there may be over 1 million species of nematode, a claim which has since been repeated in numerous publications, without additional investigation, in an attempt to accentuate the importance and ubiquity of nematodes in the global ecosystem. Many other publications have since vigorously refuted this claim on the grounds that it is unsupported by fact, is the result of speculation and sensationalism.
More recent, fact-based estimates have placed the true figure closer to 40,000 species worldwide. Nematodes have adapted to nearly every ecosystem: from marine to fresh water, from the polar regions to the tropics, as well as the highest to the lowest of elevations, they are ubiquitous in freshwater and terrestrial environments, where they outnumber other animals in both individual and species counts, are found in locations as diverse as mountains and oceanic trenches. They are found in every part of the earth's lithosphere at great depths, 0.9–3.6 km below the surface of the Earth in gold mines in South Africa. They represent 90% of all animals on the ocean floor, their numerical dominance exceeding a million individuals per square meter and accounting for about 80% of all individual animals on earth, their diversity of lifecycles, their presence at various trophic levels point to an important role in many ecosystems. They have been shown to play crucial roles in polar ecosystem; the 2,271 genera are placed in 256 families.
The many parasitic forms include pathogens in animals. A third of the genera occur as parasites of vertebrates. Nathan Cobb, a nematologist, described the ubiquity of nematodes on Earth as thus:In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, if, as disembodied spirits, we could investigate it, we should find its mountains, vales, rivers and oceans represented by a film of nematodes; the location of towns would be decipherable, since for every massing of human beings, there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our highways; the location of the various plants and animals would still be decipherable, had we sufficient knowledge, in many cases their species could be determined by an examination of their erstwhile nematode parasites. Modern Latin compound of nemat- "thread" + -odes "like, of the nature of". In 1758, Linnaeus described some nematode genera included in the Vermes.
The name of the group Nematoda, informally called "nematodes", came from Nematoidea defined by Karl Rudolphi, from Ancient Greek νῆμα and -eiδἠς. It was treated as family Nematodes by Burmeister. At its origin, the "Nematoidea" erroneously included Nematodes and Nematomorpha, attributed by von Siebold. Along with Acanthocephala and Cestoidea, it formed the obsolete group Entozoa, created by Rudolphi, they were classed along with Acanthocephala in the obsolete phylum Nemathelminthes by Gegenbaur. In 1861, K. M. Diesing treated the group as order Nematoda. In 1877, the taxon Nematoidea, including the family Gordiidae, was promoted to the rank of phylum by Ray Lankester; the first clear distinction between the nemas and gordiids was realized by Vejdovsky when he named a group to contain the horsehair worms the order Nematomorpha. In 1919, Nathan Cobb proposed, he argued they should be called "nema" in English rather than "nematodes" and defined the taxon Nemates, listing Nematoidea sensu restricto as a synonym.
However, in 1910, Grobben proposed the phylum Aschelminthes and the nematodes were included in as class Nematoda along with class Rotifera, class Gastrotricha, class Kinorhyncha, class Priapulida, class Nematomorpha. In 1932, Potts elevated the class Nematoda to the level of phylum. Despite Potts' classification being equivalent to Cobbs', both names have been used and Nematode became a popular term in zoological science. Since Cobb was the first to include nematodes in a particular phylum separated from Nematomorpha, some researchers consider the valid taxon name to be Nemates or Nemata, rather than Nematoda, because of the zoological rule that gives priority to the first used term in case of synonyms; the phylogenetic relationships of the nematodes and their close relatives among the protostomian Metazoa are unresolved. Traditionally, they were held to b