Zoology Principles of Systematics PDF

Principles of Systematics Module# 1 Principles of Systematics Basic Terminologies Basic Terminologies Taxonomy Theory and practice of classification of organisms Taxonomy is derived from Greek words “...

Principles of Systematics Module# 1 Principles of Systematics Basic Terminologies Basic Terminologies Taxonomy Theory and practice of classification of organisms Taxonomy is derived from Greek words “Taxis” which means arrangements and “Nomos” means laws /methods Basic Terminologies Taxonomy Carolus Linnaeus, the Swedish botanist, Zoologist and Physician Regarded as the father of modern taxonomy. Basic Terminologies Contribution of Carolus Linnaeus His two important contributions to taxonomy were: A hierarchical classification system The system of binomial nomenclature Basic Terminologies Carolus Linnaeus He proposed that there are three broad groups called Kingdoms into which whole nature could fit. These kingdoms were: Animals Plants and Minerals Basic Terminologies Classification It is a systematic method of arranging organisms into different groups and subgroups, based on their similarities and their differences. It makes the study of organisms very easy and convenient. Basic Terminologies Classification Organisms can be classified on the basis of several different factors: Cell nature –Are cells Prokaryotic or Eukaryotic? Cells – Do they occur Singly or in Clusters? Mode of Nutrition Level of Body Organization Basic Terminologies Aristotle-Father of Biological Classification To understand anything, one must classify it according to its parts He established numerous collective categories or genera using differentiating characteristics Basic Terminologies Aristotle-Father of Biological Classification Blooded and bloodless Two-footed vs four footed Hairy vs feathered With or without an outer shell Note: He failed to provide orderly and fully consistent classification of animals. Principles of Systematics Module# 2 Principles of Systematics Basic Terminologies Basic Terminologies Systematics According to Simpson (1961) Scientific study of kinds and diversity of organisms and of any or all relationship among them Broad term which include Taxonomy, Nomenclature and Classification etc. Professor of Biology at San Diego State University, Colombia Basic Terminologies Aims of systematics Invent worlds kinds of organisms (flora and fauna) Provide method for identification and communication To produce coherent and universal system of classification and Demonstrate evolutionary implications of biodiversity Basic Terminologies Component fields of systematics Component fields of systematics are: Biodiversity Taxonomy Classification Nomenclature Biogeography Evolutionary biology Basic Terminologies Taxon According to Simpson (1961) taxon is a group of real organisms recognized as formal unit at any level of hierarchic classification Blue birds, song birds, vertebrate refer to groups of organisms.  Basic Terminologies Taxon Taxon always refer to concrete Zoological object Species of Robins is not a taxon but category Robin is a Taxon END Principles of Systematics Module# 3 Principles of Systematics Contribution of Systematics in Biology Contribution of Systematics in Biology Systematics contribution The contribution of systematic to biology can be studied under two heads:- Theoretical Biology Applied Biology Contribution of Systematics in Biology Theoratical Biology Evolution Ecology Molecular Biology Evolutionary Biology Contribution of Systematics in Biology Evolution Evolution is a process by which plants and animals that exist today have been evolved from plants and animal of past. Before the rise of genetics, the study of evolution was carried out entirely by taxonomists. Virtually all major evolutionary problems were first pointed out and often solved by systematics. Contribution of Systematics in Biology Evolution Taxonomists helps us categorize organisms so we can more easily communicate biological information. No other branch of biology has made greater contribution to our understanding than systematics. Contribution of Systematics in Biology Ecology No through ecological surveys can be conducted without the identification of all species that are of ecological significance. Elton (1947) acknowledged the progress in ecology depends upon accurate identifications of species. Contribution of Systematics in Biology Molecular Biology Molecular biologist use genetic data for establishing relationships among different organisms. However, they need assistance of traditional taxonomist for accurate results. Examples: DNA barcoding and END taxonomist Principles of Systematics Module# 4 Principles of Systematics Contribution of Systematics in Biology Contribution of Systematics in Biology Applied Biology Agriculture and forestry Biological control Public health Quarantine Wild life management Contribution of Systematics in Biology Applied Biology Mineral prospecting National defense Environmental problem Soil fertility In commerce Contribution of Systematics in Biology Agriculture and Forestry In order to control and minimize pest attack on crops and diseases caused by vector It is necessary to know about correct names of pests Taxonomists give us correct identification of pests Identification is vital for control  Contribution of Systematics in Biology Involved in designing biological control programs of pests Determination of exact country of origin and their parasite and parasitoids is compulsory. Biological Control  Contribution of Systematics in Biology Asian citrus psylid is serious pest of citrus orchards Its origin is Asia Tamarixia radiata, a parasitic wasp Asian Citrus psylid Tamaria radiata was introduced from Pakistan to California to control this pest. (Hoddle & Pandey, 2014) Best example of classical biological control. Contribution of Systematics in Biology Public Health Number of diseases are spread by Arthropods which are controlled by targeting specific species. For example: All Anopheles maculipennis are not responsible for transmitting malaria. Out six siblings some are involved in transmission of malaria. Contribution of Systematics in Biology Public Health Although the species are virtually indistinguishable morphologically, they are isolated reproductively, in part because they breed in different habitats. Taxonomists help to identify this particular sibling species for END effective control at minimum cost. Principles of Systematics Module# 5 Principles of Systematics Contribution of Systematics in Biology Contribution of Systematics in Biology Quarantine Many diseases are spread from one country to other via transportation. Respective Governments established quarantine labs at aerodromes and ports etc Taxonomists help in prompt identification of these diseases Contribution of Systematics in Biology Wild Life management The indiscriminate killing and felling of trees create disturbance in natural environment. It help environmental protectors by identifying economically and ecologically important wild life. It is important for preservation and protection of biodiversity. Contribution of Systematics in Biology Mineral Prospecting The identification of fauna and flora by paleontologists in sedimentary rocks show the sequence of geological events Which help in search for fuels and mineral deposits. Example: It attain great success in American industrialization  Contribution of Systematics in Biology During World War II (On November 3, 1944), Japan released balloon bombs, into the Pacific jet stream Created havoc in the forest of north east America. Balloons covered with sand contained a large number of shells of micro-organisms. Bombing of this beach area destroyed the National Defense balloon launching site. Contribution of Systematics in Biology Detection of Environmental Problems Phytoplankton and zooplankton a re sensitive to changes in water quality. They are good indicators for changes in water quality as they respond quickly to changes in nutrient input. Taxonomists help to detect such problem by identifying specific species.  Contribution of Systematics in Biology Taxonomist help to detect organisms that enhance soil fertility For example bacteria, earthworms etc. Soil Fertility Contribution of Systematics in Biology In commerce Systematics play role in increasing and improving the qualities of commercially used animal products such as: Honey Silk Lac END Dyes etc Principles of Systematics Module# 6 Principles of Systematics Binomial Nomenclature Binomial Nomenclature Scientific names of species is a combination of two names: Generic name Species name Binomial Nomenclature Spider Oxyopes javanus is found in agro-ecosystems. The first part of a scientific name, Oxyopes, is called the genus. The second part of a scientific name, javanus is in this example, is the species name Binomial Nomenclature Hottentotta tamulus, the Indian red scorpion also known as the eastern Indian scorpion, is a species of scorpion of the family Buthidae. It occurs in most of India, eastern Pakistan and the eastern lowlands of Nepal, and recently from Sri Lanka.  Binomial Nomenclature Rana tagrina is an amphibian which is solitary and nocturnal in nature. They inhabit holes and bushes near water source. They do not stay in water for longer time. https://en.wikipedia.org/wiki/ Hoplobatrachus_tigerinus#/media/ File:HoplobatrachusTigerinus.jpg They belong to order anura. Principles of Systematics Module# 7 Three Domain system Archaea Eubacteria Eukaryota Three Domain system A domain is a broadest taxonomic category. All organism belong to one of the three domains, depending upon their characteristics. A single domain can contain one or more kingdoms. Introduced by Charl Woese et al. In 1990. Three Domain system Domain of Viruses Viruses are DNA and RNA shielded by protein coat called capsid. Viruses do not have a domain Three Domain system Three Domain system https://biologydictionary.net/intron/ Principles of Systematics Module# 8 Principles of Systematics Five Kingdom Classification Five Kingdom Classification Two Kingdom classification Plants (Autotrophs) Animals (Hetrotrophs ) Problem Euglena Solution by Ernst Hackel (1866) Protista Five Kingdom Classification E- Chatton in 1937 introduced the term “Procariotique” to describe bacteria and “Eucariotique” to describe animals and plant cells. Five kingdom classification was proposed by Robert Whittaker in 1967. Five Kingdom Classification Morgulis and Schwatz in 1988 modified R. Whittaker classification. They considered genetics along with cellular organization and mode of nutrition in classification. Five Kingdom Classification Five kingdoms proposed by Robert Whittaker include: Monera Protista Fungi Plantae Animalia Principles of Systematics Module# 9 Principles of Systematics History of Taxonomy  History of Taxonomy Taxonomy is as old as the language skill of mankind. Taxonomy is the science of naming, describing and classifying organisms including all plants, animals and microorganisms of the world. Taxonomy identifies and enumerates the components of biological diversity. https://Britannica.com/science/taxonomy History of Taxonomy Native tribes used to call the species on the basis of their morphological characters Development of scientific theory of classification ….a remarkably recent phenomenon  History of Taxonomy Simpson in 1961 gives a valuable survey of History of Taxonomy. Simpson was the most influential paleontologists of the twentieth century. He published extensively on the taxonomy of fossil and extinct mammals. George Gaylord Simpson (1902-1984) https://www.google.com/search? q=george+gaylord+simpson+pic&sxsrf=ALeKk016UQ5865EIGFEM0Awr yp5IHsxm- Q:1613054410489&source=lnms&tbm=isch&sa=X&ved=2ahUKEwilsI_ 5hLuAhUJnlkKHYD5DkgQ_AUoAXoECA8QAw&biw=1366&bih=625#img rc=siNionRQ1ItxWM  History of Taxonomy Frederick Smith worked in the zoology department of British Museum from 1849. He published from 1851 to 1870 on ant taxonomy. During the 28 years of his activity he describe 25 genera, 702 species and subspecies of whic Frederick Smith 1805-1879 https://www.google.com/search? hare. q=frederick+smith+pic+pic+taxonomy&tbm=isch&ved=2ahUKEwiSPCJi uLuAhUP_BoKHfOBCwsQ2cCegQIABAA&oq=frederick+smith+pic+pic+t axonomy&gs_lcp=CgNpbWcQA1CQEFj1KWCxLWgAcAB4AIABjQOIAegX kgEFMi0xLjiYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei=B kQlYJLdHo_4a_ODrlg&bih=625&biw=1366#imgrc=k331uXCLcv1lsM  History of Taxonomy Thomas E.Mittler was an Austrian entomologist. He worked on history of higher taxonomy and also on the classification of insects Thomas E. Mittler (1928-2012) https://www.google.com/search? q=thomas+E.Mittler+pic+pic+taxonomy&tbm=isch&ved=2ahUKEwiSPC JiuLuAhUP_BoKHfOBCwsQ2cCegQIABAA&oq=frederick+smith+pic+pic +taxonomy&gs_lcp=CgNpbWcQA1CQEFj1KWCxLWgAcAB4AIABjQOIAe gXkgEFMi0xLjiYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei =BkQlYJLdHo_4a_ODrlg&bih=625&biw=1366#imgrc=k331uXCLcv1lsM  History of Taxonomy Mayr in 1982 provided a details of various periods of History of Taxonomy His work contributed to the conceptual revolution that led to modern evolutionary synthesis of taxonomy and systematics Ernst Mayr (1904- 2005) https://www.google.com/search? q=ernst+mayr+pic+taxonomy+&tbm=isch&ved=2ahUKEwjs6e2JjuLuAh XBwIUKHfhfAU0Q2cCegQIABAA&oq=ernst+mayr+pic+taxonomy+&gs_l cp=CgNpbWcQA1D6IlibLmD8MmgAcAB4AIABjgSIAcgXkgEHMy0zLjMu MZgBAKABAaoBC2d3cy13aXotaW1nwAEB&sclient=img&ei=OEglYOztC 8GBlwT4v4XoBA&bih=625&biw=1366#imgrc=PdnA5xdNdrOdwM// Principles of Systematics Module# 10 Principles of Systematics History of Taxonomy History of Taxonomy Mayr described the History of Taxonomy into four periods:  1st Period  2nd Period  3rd Period  4th Period  History of Taxonomy 1st Period (Study of local fauna) Several early Greek scholars notably Hippocrates enumerated the types of animals But he did not classify. Hippocrates (460-377 B.C.) https://www.google.com/search? q=hippocratespic+taxonomy&tbm=isch&ved=2ahUKEwi19KNjuLuAhUE PhoKHY92BQQQ2cCegQIABAA&oq=hippocratespic+taxonomy&gs_lcp =CgNpbWcQAzoGCAAQCBAeUM_LJliV9CZgy_cmaABwAHgCgAGHBYgB vTySAQczLTYuNy40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=im g&ei=QEglYLXbCIT8aI_tlSA&bih=625&biw=1366#imgrc=77dKLgexqooJ oM  History of Taxonomy 1st Period (Study of local fauna) Aristotle known as father of biological classification, referred to the major groups of animals. Aristotle (384-322 B.C.) https://www.google.com/search? q=aristotle+taxonomy&tbm=isch&ved=2ahUKEwi19KNjuLuAhUEPhoK HY92BQQQ2cCegQIABAA&oq=hippocratespic+taxonomy&gs_lcp=CgN pbWcQAzoGCAAQCBAeUM_LJliV9CZgy_cmaABwAHgCgAGHBYgBvTySA QczLTYuNy40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei= QEglYLXbCIT8aI_tlSA&bih=625&biw=1366#imgrc=77dKLgexqooJoM History of Taxonomy Aristotle also made distinction in insects He first used the following terms: Coleoptera and Diptera History of Taxonomy He established numerous collective categories, or genera using differentiating characters History of Taxonomy Aristotle made further categories of animals His thinking dominated for next two thousand years After his death no system of classification were recognized Principles of Systematics Module# 11 Principles of Systematics History of Taxonomy History of Taxonomy From 1551 rapid progress started in knowledge about animals. There are two major forms of classification in first period  History of Taxonomy Taxonomy based on local fauna reached its peak by the work of Linnaeus (1707-1778) Carl Linnaeus (1707-1778) https//www.google.com/search? q=carl+linnaeus+taxonomy&tbm=isch&ved=2ahUKEwi19KNjuLuAhUEP hoKHY92BQQQ2cCegQIABAA&oq=hippocratespic+taxonomy&gs_lcp= CgNpbWcQAzoGCAAQCBAeUM_LJliV9CZgy_cmaABwAHgCgAGHBYgBvT ySAQczLTYuNy40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img &ei=QEglYLXbCIT8aI_tlSA&bih=625&biw=1366#imgrc=77dKLgexqooJo M History of Taxonomy Downward classification are the principles of logical division which consist of dividing the larger groups based on dichotomy into smaller groups. e.g, Animals History of Taxonomy Linnaeus adopted the principle of downward classification in 15th edition of his book (Systema naturae) He for the first time applied binomial nomenclature to animal kingdom. History of Taxonomy Linnaeus’s idea was largely acceptable for the classification of insects. Not acceptable for the classification of birds, amphibians, and lower vertebrates (Vermes)  History of Taxonomy Buffon prepared the way for the biological species concept, by using sterility barriers instead of degree of morphological differences as the species criterion Comte de Buffon (1707-1778) https//www.google.com/search? q=comte+deBuffon+taxonomy&tbm=isch&ved=2ahUKEwi19KNjuLuAh UEPhoKHY92BQQQ2cCegQIABAA&oq=hippocratespic+taxonomy&gs_l cp=CgNpbWcQAzoGCAAQCBAeUM_LJliV9CZgy_cmaABwAHgCgAGHBY gBvTySAQczLTYuNy40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient= img&ei=QEglYLXbCIT8aI_tlSA&bih=625&biw=1366#imgrc=77dKLgexqo oJoM Principles of Systematics Module# 12 Principles of Systematics History of Taxonomy History of Taxonomy By the mid of 18th century shortcomings of downward classification system were recognized. Gradually replaced by upward classification system History of Taxonomy It consists of assembling species by inspection into groups of similar and related species and forming hierarchy by again grouping of similar taxa of next lower rank.  History of Taxonomy Buffon in 1749 supported this system. He said that the only way to design a method is to group together the things that resemble each other and separate the things that differ from each other Comte de Buffon (1707-1778) https//www.google.com/search? q=comte+deBuffon+taxonomy&tbm=isch&ved=2ahUKEwi19KNjuLuAh UEPhoKHY92BQQQ2cCegQIABAA&oq=hippocratespic+taxonomy&gs_l cp=CgNpbWcQAzoGCAAQCBAeUM_LJliV9CZgy_cmaABwAHgCgAGHBY gBvTySAQczLTYuNy40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient= img&ei=QEglYLXbCIT8aI_tlSA&bih=625&biw=1366#imgrc=77dKLgexqo oJoM  History of Taxonomy Anderson 1763 (Botanist) applied this design for the classification of plants James Anderson (1738– 1809) https//www.google.com/search? q=comte+deBuffon+taxonomy&tbm=isch&ved=2ahUKEwi19KNjuLuAh UEPhoKHY92BQQQ2cCegQIABAA&oq=hippocratespic+taxonomy&gs_l cp=CgNpbWcQAzoGCAAQCBAeUM_LJliV9CZgy_cmaABwAHgCgAGHBY gBvTySAQczLTYuNy40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient= img&ei=QEglYLXbCIT8aI_tlSA&bih=625&biw=1366#imgrc=77dKLgexqo oJoM History of Taxonomy Cuvier recognized five phyla Georges Cuvier (1769-1832) https://www.google.com/search? q=george+cuvier+1769+to+1832&tbm=isch&ved=2ahUKEwjQx9O- kOLuAhUMEhoKHf1eCH4Q2- cCegQIABAA&oq=george+cuvier+1769+to+1832&gs_lcp=CgNpbWcQA zoECCMQJzoECAAQQzoHCCMQ6gIQJzoFCAAQsQM6AggAOggIABCxAxC DAToECAAQAzoGCAAQBRAeOgQIABAeUNkRWJ6PAWCskgFoAXAAeAKA AbsDiAHCbpIBBjMtMzQuNpgBAKABAaoBC2d3cy13aXotaW1nsAEKwAE B&sclient=img&ei=v0olYJDsL4ykaP29ofAH&bih=625&biw=1366#imgrc =_rEsvqaiDKV5CM History of Taxonomy Van Baer, Owen divided all species into limited no. of groups each representing a distinct type https://www.www.google.com/search?q=karl+richaed+-oven- 1769+to+1832&tbm=isch&ved=2ahUKEwjQx9OkOLuAhUMEhoKHf1eC H4Q2cCegQIABAA&oq=george+cuvier+1769+to+1832&gs_lcp=CgNpb WcQAzoECCMQJzoECAAQQzoHCCMQ6gIQJzoFCAAQsQM6AggAOggIAB CxAxCDAToECAAQAzoGCAAQBRAeOgQIABAeUNkRWJ6PAWCskgFoAXA AeAKAAbsDiAHCbpIBBjMtMzQuNpgBAKABAaoBC2d3cy13aXotaW1nsA EKwAEB&sclient=img&ei=v0olYJDsL4ykaP29ofAH&bih=625&biw=1366 #imgrc=_rEsvqaiDKV5CM History of Taxonomy Developments during Linnaeus and Darwin Period 1. Specialization became more pronounced. Many authors identified birds, beetles, or butterflies 2. Classification became more hierarchical and soon the categories family and phylum were added 3. Philosophical guidelines were rejected 4. Search for a natural system was intensified History of Taxonomy This thought was applied by a botanist in 1873 and later by nearly all zoologists. This shift from downward classification to upward classification was a philosophical change  History of Taxonomy Evolutionary thought was widespread in 18th century Darwin believed in fixity of species but after observing natural fauna in Galapagos island, he begin to believe in the plasticity of species Charles Darwin (1809-1882) https://www.google.com/search? q=charles+darwin&tbm=isch&ved=2ahUKEwi5vpykneLuAhUN- YUKHSv2Dr4Q2- cCegQIABAA&oq=charles+darwin&gs_lcp=CgNpbWcQAzIECAAQQzICC AAyAggAMgIIADICCAAyAggAMgIIADICCAAyAggAMgIIADoHCCMQ6gIQJ zoECCMQJzoFCAAQsQM6CAgAELEDEIMBOgcIABCxAxBDULLGJFid- SRgzvskaAFwAHgDgAHWBYgB4kOSAQkzLTYuNi42LjGYAQCgAQGqAQtn d3Mtd2l6LWltZ7ABCsABAQ&sclient=img&ei=KlglYLmBAY3ylwSr7LvwC w&bih=625&biw=1366#imgrc=mrcMmxqef7ryCM  History of Taxonomy Empirical taxonomists were greatly influenced by Darwin’s idea. The phylogenetic tree of Ernest Haeckel also stimulated the empirical workers. Ernest Haeckel (1834-1919) Large number of new species https://https://www.google.com/search? q=ernst+hackel&tbm=isch&ved=2ahUKEwiH3uDFn- were discovered and described. LuAhUt5IUKHQxDDdoQ2- cCegQIABAA&oq=ernst+hackel&gs_lcp=CgNpbWcQAzICCAAyBggAEAo QGDIGCAAQChAYMgYIABAKEBgyBggAEAoQGDIGCAAQChAYMgYIABAK EBg6BAgjECc6BAgAEEM6BwgjEOoCECc6BQgAELEDOgQIABAeOgQIABA YULWsDFjy5wxgpu0MaAFwAHgAgAGCBogBrUWSAQkzLTguMy42LjKYA QCgAQGqAQtnd3Mtd2l6LWltZ7ABCsABAQ&sclient=img&ei=iVolYMf1 DK3IlwSMhrXQDQ&bih=625&biw=1366#imgrc=cIElbdaRJgSkeM History of Taxonomy The greatest development of modern taxonomy started around 1930, when the workers realized that the Linnaeus species based on one or two specimens are not as perfect as those which are based on population History of Taxonomy Due to this Mayr in 1942 considered species as a group of interbreeding natural population. This idea of population taxonomy was useful in developing the polytypic concepts. New terms like new systematics and biosystematics were added to extend the taxonomic theory. History of Taxonomy The publication of the book ‘new systematics’ Become a landmark in the History of Taxonomy. Thus taxonomy got a new label of biological taxonomy By 1955 taxonomy reach such a status that it was called taxonomic explosion History of Taxonomy New systematic deal exclusively with the species level. The present day taxonomic work include all available differences and similarities.  History of Taxonomy Instead of morphology as an original base, phylogenetic adaptations, embryological patterns, biochemical variations, genetic variabilities and similarities, behavioral characteristics are all applicable to taxonomic study END Principles of Systematics Module# 13 Principles of Systematics Basic Definitions Basic Definitions Sibling Species Two or more than two closely related species which are mor­ phologically alike but behaviorally or reproductively isolated from each other. Examples are Drosophila persimilis and D. pseudoobscura. Basic Definitions Sibling Species The mosquito Anopheles maculipennis complex consists of several sub­species, of which a few are vector of malaria and the rest are harmless. Basic Definitions Monotypic Species species with a single subspecies, called monotypic species Example: Bardala labarda Polytypic Species A species contains two or more subspecies Examples are tiger, Panthera tigris which has several subspecies  Basic Definitions Endemic species The species which are found in a particular region, called endemic species. Example The Dar­winian finches are the endemic species of Galapagos Islands END Indus dolphin in Pakistan Principles of Systematics Module# 14 Principles of Systematics Basic Definitions Basic Definitions Deme A deme is a sub-population (a smaller group within the population) that can freely interbreed. A population is usually made of several demes (groups) that are partially isolated from each other. Basic Definitions Deme Often a geographical barrier limits gene flow between demes, but not sufficiently to result in speciation. Enough gene flow occurs between demes ensuring that all of it's members remain the same species.  Basic Definitions Cline A cline is the gradual change in the phenotypes and genotypes of a species across a geographical gradient Allele frequencies and traits https://www.pathwayz.org might vary slightly across the geographical gradient because of different selection pressures.  Basic Definitions Types of cline Smooth cline Step cline https://www.pathwayz.org Basic Definitions Clade A clade is a group of organisms that evolved from a common ancestor Eutheria is one mammalian clade and the other is Metatheria, which includes marsupials. Another example of a clade could be birds: they all also descended from a common ancestor. Principles of Systematics Module# 15 Principles of Systematics Concept of Speciation and Causes Concept of Speciation and Causes Speciation Speciation refers to the creation a new species. Through this process, the earliest groups of similar organisms were able branch out and populate the world with millions of different varieties of life Basic Definitions Types of speciation Anagenesis A single species may change over time into a new form that is different enough to be considered a new species. One species replaces other No net change in number of species Basic Definitions Types of speciation Cladogenesis A species may become split into two groups that no longer share the same gene pool. Net increase in number of species Increase in diversity Concept of Speciation and Causes Cusses of speciation Geographical Isolation Behavioural isolation Reproductive isolation END Principles of Systematics Module# 16 Concept of Speciation and Causes Types of speciation Concept of Speciation and Causes Types of speciation Allopatric speciation Peripatric speciation Sympatric speciation Parapatric speciation Concept of Speciation and Causes Allopatric Speciation The most common form of speciation Occurs when populations of a species become geographically isolated. Concept of Speciation and Causes Allopatric Speciation When populations become separated, gene flow between them ceases. Over time, the populations may become genetically different Concept of Speciation and Causes Examples Speciation is the Galápagos finch Different species of these birds live on different islands. The finches are isolated from one another by the ocean. Over millions of years, each species of finch developed a unique beak that is especially adapted to the kinds of food it eats. Concept of Speciation and Causes Principles of Systematics Module# 17 Principles of Systematics Sympatric Speciation Sympatric Speciation A speciation in which a species is evolved from a single common ancestral species while inhabiting the same geographical range. Share the same habitat but become reproductively isolated from each other. More common in plants Sympatric Speciation Popyploidy in plants Plants produce offspring that are polyploid. Hence, the offspring live in the same environment as their parents but are reproductively isolated.  Sympatric Speciation Example 200 year ago ancestor of maggot flies were used to lay eggs on hawthorn. Now they lay eggs on hawthorn (native to America) and domestic apples (introduced) https://images.app.goo.gl/5Q15k3p4fVkKcktA7 Host shift/genetic differences (Coyne, 2007) Principles of Systematics Module# 18 Principles of Systematics Parapatric Speciation  Parapatric Speciation Parapatric speciation It occurs when populations are separated not by a geographical barrier, such as a body of water, but by an extreme change in habitat. Populations in these area may interbreed. https://en.wikipedia.org/wiki/Parapatric_speciation#/media/ Charles Darwin was the first to File:Ring_Species_(gene_flow_around_a_barrier).png propose this mode of speciation. Parapatric Speciation Parapatric speciation Although interbreed but reduced gene flow. They often develop distinct characteristics and lifestyles. Reproductive isolation is rather temporal or behavioral. It is extremely rare.  Parapatric Speciation Example Population of grass plant is present near mining area Soil near mining area is infused with metals due to which plants grow slowly than those that grows away from mines. https://images.app.goo.gl/iMY6DE1PcER2Dx1k7 As a result, two populations of grasses arise having different flowering time.  Parapatric Speciation Example A study of tropical cave snails (Georissa saulae) found that cave-dwelling population descended from the above- ground population, likely speciating in parapatry https://www.google.com/search? q=cave+snails&tbm Principles of Systematics Module# 19 Principles of Systematics Paripatric Speciation  Paripatric Speciation Paripatric speciation Peripatric speciation is a mode of speciation in which a new species is formed from an isolated peripheral population. Resemble alloprtraic speciation/barriers https://en.wikipedia.org/wiki/Peripatric_speciation#/media/ File:Peripatric_Speciation_Schematic.svg Isolating population is small  Paripatric Speciation Paripatric speciation Peripatric speciation is a mode of speciation in which a new species is formed from an isolated peripheral population. Resemble alloprtraic speciation/barriers https://www.youtube.com/watch?v=7TNN-WGYWks Isolating population is small  Paripatric Speciation Example An example of this is the London Underground mosquito, a variant of the mosquito Culex pipiens, which entered in the London Undgerground in 19th century. https://www.google.com/search? It is found in the London q=london+underground+mosquito&h Underground railway system l  Paripatric Speciation Example Evidence for its speciation includes genetic divergence, behavioral differences, and difficulty in mating. END Principles of Systematics Module# 20 Principles of Systematics Typological Species Concept Typological Species Concept Species is the basic unit of classification according to the International Commission of Zoological Nomenclature. Survey of taxonomic literature shows that there are more than 20 species concepts. Typological Species Concept Typological species concept This concept was proposed by Aristotle and Plato According to this concept “A certain pattern of features is found in each species of organisms and all members of species show maximum equality in this format” Example: certain pattern in dogs Typological Species Concept Typological species concept Monotypic species Polytypic species Typological Species Concept Postulates of Typological species concept Species consist of similar individuals sharing the same essence. Each species is separated from all others by sharp discontinuity. Each species is completely constant through time. There are strict possible limits to variations within any one species.  Typological Species Concept Example Two macaw species, blue-and- yellow macaw Ara ararauna and Ara ararauna Ara macao the scarlet macaw Ara macao are considered different species due to different coloration. In nature, their habitats overlap but they not produce hybrids sterile hybrid except in captivity. Catalina macaw  Typological Species Concept Strengths Applicable to living or extinct species. Doesn’t depend on complex genetic analysis. Anchura substriata Morphology can be readily https://www.google.com/search? q=macaw&tbm=isch&ved=2ahUKEwiQyL observed, without harming the organisms.  Typological Species Concept Problems with Typological species concept Polymorphism within populations. Sibling or cryptic species. Geographical variations among populations END Principles of Systematics Module# 21 Principles of Systematics Biological Species Concept Biological Species Concept According to Biological species concept: Species are groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups.” Ernst Mayr(1942,1963) Biological Species Concept Can successfully interbreed and produce fertile offspring. A species’ integrity is maintained by interbreeding within a species. Biological Species Concept Why members of species resemble This concept explains why members of species resemble and differ from other species. When organisms breed they shuffle their gene pool which gives the species its identity. Genes are not shared with other species so they look different.  Biological Species Concept Biological species concept Members of species constitute: Ecological unit Reproductive unit Genetic unit END Principles of Systematics Module# 22 Principles of Systematics Biological Species Concept Biological Species Concept Biological species concept Ecological unit Reproductive unit Genetic unit.” Ernst Mayr (1942, Darwin of 20th century) Biological Species Concept Biological species concept Most widely accepted species concept. Dobzhansky (1951) and Hanson (1981) accepted the definition of biological Species concept because of two reasons: Gene pool Reproductive isolation Biological Species Concept https://www.youtube.com/watch?v=3Chz-XJHvNE Principles of Systematics Module# 23 Principles of Systematics Drawbacks of Biological Species Concept Drawbacks of Biological Species Concept Drawbacks Asexual reproducing organisms. Fossils Sibling or cryptic species Distinguishing between species on the basis of reproductive separation is problematic because reproductive isolation is often incomplete. Drawbacks of Biological Species Concept Asexual reproduction/Uniparental reproduction Not applicable on apomictic species Do not fulfill interbreeding criterion (Most important in BSC) Apomictic groups (parthenogenesis, apomixis, budding etc) Drawbacks of Biological Species Concept Asexual reproduction/Uniparental reproduction Uniparental reproduction is Common in lower invertebrates and lower vertebrate Decedents are called agamospecies, binoms or paraspecies According to Mayr (1988a) these are not species Drawbacks of Biological Species Concept Sibling species/Cryptic species As they are morphological similar but reproductively isolated Incompleteness of Speciation/fossil record Evolution is gradual and continuous process. However, fossil record is not complete END Principles of Systematics Module# 24 Principles of Systematics Drawbacks of Biological Species Concept Drawbacks of Biological Species Concept Interbreeding between two different species According to BSC two different species can not breed and produce fertile offsprings However, there are exceptions Drawbacks of Biological Species Concept https://www.youtube.com/watch?v=3Chz-XJHvNE Principles of Systematics Module# 25 Principles of Systematics Evolutionary Species Concept Evolutionary Species Concept Evolutionary species concept Simpson (1940s) An evolutionary species “is a single lineage of ancestor- descendant populations of organisms which maintains its: Identity from other such lineages [in space and time] Own evolutionary tendencies historical fate” (Wiley, 1981) Evolutionary Species Concept Evolutionary species concept Initially developed to define fossil species. Applicable to both sexually and asexually reproducing species and emphasizes common descent.  Evolutionary Species Concept Drawbacks Arbitrary: how to define independent roles and tendencies. Does not provide mechanism. END Principles of Systematics Module# 26 Principles of Systematics Taxonomic Characters Taxonomic Characters Character It is any attribute of member of taxon by which it may differ from member of other taxon. A heritable trait possessed by an organism Characters are usually described in terms of character states. Taxonomic Characters Character state One of the variant conditions of a trait. Binary states: For example: "hair present" vs. "hair absent," where "hair" is the character, and "present" and "absent" are its states Multistate characters: Yellow, white or pink flowers or AGCT for nucleotide sequence data. Taxonomic Characters Qualities of key characters Apply to all member of taxon Fairly stable and durable Qualitative and absolute Detectable without special equipment's, dissection or histological preparations  Taxonomic Characters Taxonomic Characters are illustrated as: Morphological character Physiological character Behavioral character Ecological character Geographic character Molecular and biochemistry character Ontogenetic character END Principles of Systematics Module# 27 Principles of Systematics Morphological Characters Morphological Characters Morphological Characters Morphology describe the structural features. Morphological characters include: External morphology Genetelic structure Internal morphology Embryology Karyology and other cytological differences  Morphological Characters General external morphology The apparent features are easy to detect and observe. e.g. Plumage of birds, scales of fish and reptiles, pelage of mammals, phylogenetically significan sutures and sclerites of arthropod body etc. https://tse2.mm.bing.net/th?id=OIP.k_dPDFg2fI7 OVNpR7Y72-gHaDa&pid=Api&P=0&w=  Morphological Characters Genetalic structures The genital structure of each specie are different to depict the reproductive isolation. Used to delimit species Key and Lock model Highly effective insects https://www.researchgate.net/profile/Aidas_Saldaitis/ Genetalic structures appear to be publication/321343778/figure/fig2/AS:568147356336130 @1512468293710/Male-genitalia-and-leg-structures-of-the among the first to change in the -C-katsumii-holotype_Q320.jpg course of speciation.  Morphological Characters Coloration Color pattern and other aspects of coloration are convenient characters in certain group of animals. Bird and coloration except few genera with sibling species. Same is true or certain reef fishes and butterflies Many subspecies are indentified on the basis of colour END Principles of Systematics Module# 28 Principles of Systematics Morphological Characters  Morphological Characters Internal morphology Internal anatomy provides Taxonomic Characters for all groups of higher animals. The extend to use vary from group to group. The skull of routinely used in classification of higher mammals. Teeth and bones of fossils and https://www.google.com/search? q=evolution+in+skulls+of+vertebrates other hard parts.  Morphological Characters Embryology Various larval stages, embryology and even eggs may provide taxonomic information. Sibling species of Anopheles maculipenis------Egg structure Identification of white flies are based on pupae https://i1.wp.com/orbitbiotech.com/wp-content Comparative embyological stages /uploads/2018/04/embryonic-development-Orbit- Biotech-Training.jpg?ssl=1 like cleavage, blastulation, gastrulation etc are helpful  Morphological Characters Karyology and other cytological factors Karyology is description of size, shape and number of chromosomes The simplest cytological character is chromosomal number (species specific) Comparison of closely related https://www.liberaldictionary.com/wp-content /uploads/2019/02/karyology-4570.jpg species (sibling species) Establishing phyletic lineage Principles of Systematics Module# 29 Principles of Systematics Physiological Characters Physiological Characters Physiological Characters Physiological characters are low weight characters and are variable: All structures are product of physiological process and are thus physiological characters. This character can not be studied in preserved animals. Physiological Characters Physiological Characters Metabolic activities Body secretion Serological protein and other biochemical differences Genic sterility factor Physiological Characters Metabolic Factors Metabolic factors/enzymes help to find the relations in the closely related species e.g. Gram +ive and Gram –ive bacteria  Physiological Characters Body secretion Body secretions also have the consistent pattern Links can be created by finding the number Size and Structure of the glands e.g. waxy secretion of scale insects https://thecotyledon.files.wordpress.com /2010/10/scale-honey.jpg Principles of Systematics Module# 30 Principles of Systematics Physiological Characters Physiological Characters Serological protein and other biochemical differences Serology is concerned with the nature and interaction of antigens and antibodies. Antigens are the substances capable for inducing the formation of antibodies when introduced into the blood stream of animals. Physiological Characters According to antibodies produced in response to the introduction of foreign antigen Bovden (1943) Protein antigens are conservative hereditary trait. Proteins of one organism react more strongly with the antibodies of closely related organism than more distantly related. Physiological Characters Good precipitin technique are reveal the relative degree of biochemical similarity of protein antigens among organisms.  Physiological Characters Genic sterility factors Reproductively incompatible species cannot reproduce new young one Only closely related species can hybridize successfully. As a result give genetically sterile species. Cross fertility in Dobkey and Hourse- Mule Cross fertility in ducts (species END and genera) Principles of Systematics Module# 31 Principles of Systematics Behavioral Characters Behavioral Characters Behavioral characters Behaviour is one of the most important source of Taxonomic Characters. They are more superior than morphological characters in the study of closely related species. Especially in sibling species Mating behaviour, egg laying, nesting behaviour, drinking habit of birds etc. Behavioral Characters Behavioral characters Mating calls of frogs, toads and crickets are used in species delimitation. Webs pattern in spiders can be at various level in classification.  Behavioral Characters Reproduction Mating and reproduction behavior of species help in taxonomic classification and also help in determining reproductive isolation and speciation. E.g. slugs https://tse3.mm.bing.net/th?id=OIP.eubyf9OPir29 CdF7wsFukQHaDO&pid=Api&P=0&w=392&h=171  Behavioral Characters Other behavior pattern The living, eating and nesting behavior of the animals also depicts the taxonomic character e.g. drinking habit of pigeon and sand grouse, use of mud in nest https://media.buzzle.com/media/images-en/photos /birds/peacocks/1200-77866817-peacock-drinking-water building.jpg Behavioral Characters Drawbacks Can not be studied in preserved material It is intermittent even in living animal. Some behaviours are seasonal Change within 24 hours Principles of Systematics Module# 32 Principles of Systematics Ecological Character Ecological Character Ecological characters Each species has specific niche Types of niches Habitats and hosts environment Food sources Seasonal variation Parasite and host interaction reaction Ecological Character Habitats and host environment Habitat of the organisms is not same Species cannot coexist at same place or in same environment or partitioned their resource to avoid competition. Ecological Character Food and seasonal variation Food sources also varies like in parasites and many others. Characteristics of organism also vary depending on season e.g. plumage of birds and breeding coloration  Ecological Character Parasite and host interaction reaction Structural changes can occur in host after parasitic attack Various responses of body like distortion, swelling etc. https://tse4.mm.bing.net/th?id=OIP.CDWG77aR8Ie8a 2HGocriegHaEV&pid=Api&P=0&w=341&h=201 Principles of Systematics Module# 33 Principles of Systematics Ecological Character Ecological Character Ecological Character Every species has its own ecological niche in nature differing from its close relatives in (spider example) Food preference Breeding season Tolerance to physical factors Resistance to predators Compotators and pathogens Ecological Character Ecological Character Larvae of both Drosophila mulleri and Drosophila aldriachi live simultaneously in decaying pulp of the fruits of cactus Opuntia lindheimeri. Both species are specialized in using certain types of yeast and bacteria.  Ecological Character Ecological Character Similarly tapeworms of man and rodents and Ascaris of man and pigs are host specific. Each species of Galapagos finch is also specialized according its habitat/ environments END Principles of Systematics Module# 34 Principles of Systematics Geographical Characters Geographical Character Geographical Character Each taxon has a geographical range Range changes as the taxon evolve Distribution of taxa provide past history Geographic characters are important at two levels Microtaxonomy Macrotaxonomy Geographical Character Geographical Character Taxonomists are important in two types of geographical characters: General biogeogrphical patterns, which are especially useful in arrangement of higher Texa Allopatric-sympatric relationship, which is helpful in determining wether or not two species are conspecific.  Geographical Character Sympatric-allopatric relationship of population These isolation pattern that occur in the population also determine the links in population https://s-media-cache-ak0.pinimg.com/736x/18/ 49/1c/18491ced4bf91ceac2f85a3fdee59a5f.jpg Principles of Systematics Module# 35 Principles of Systematics Molecular and biochemistry character Molecular and Biochemistry Character Molecular and biochemistry character This character as taxonomic character is also an approach for the evolutionary links and relations determines if classical taxonomy is defined. Molecular and Biochemistry Character Molecular and biochemistry character Immunological distances Electrophoretic differences Amino acid sequence of protein DNA hybridization DNA and RNA sequence Molecular and Biochemistry Character Amino acid sequences Amino acid sequences help to determine the links. This approach as a taxononmic character is more absolute.  Molecular and Biochemistry Character DNA and RNA sequences These sequences help to determine the direct links on the basis of sequences But these sequences can also undergo some changes under the evolutionary pressure https://tse2.mm.bing.net/th?id=OIP.Uo3B4dsPEz- PEzHf3uJ4OwHaCz&pid=Api&P=0&w=517&h=197 Molecular and Biochemistry Character Electrophoretic differences This method determine the difference in the isozyme and allozyme. Can help to determine share character among taxa.  Molecular and Biochemistry Character DNA hybridization This method is used to determine the genetic distance between two organisms Mainly measure the genetic similarity https://www.genome.gov/sites/default/ files/tg/en/illustration/hybridization.jpg Principles of Systematics Module# 36 Principles of Systematics Weighing of Characters Weighing of Characters Any attribute by which member of a taxon differ Raw material of classification Amount of phyletic information contents in a given character More phyletic information----high weigh Low phyletic information---low weight Weighing of Characters Animal character may of high weight ----mostly used by taxonomist Low weight---rarely used Also characters of intermediate weight Challenge for taxonomists which discordant character should be truested? Weighing of Characters Process to determine that which character is more reliable is called weighting.  Weighing of Characters 1. Priori (before/without phyletic information) Proposed by Artistotle 2. Posteriori Proposed by Adenson (after phyletic information collection) All classification is based on this model. END Principles of Systematics Module# 37 Principles of Systematics Correlated Characters Correlated Characters Characters which are functionally correlated have very low weight They have low phylogenetic content Do not deserve to be treated as separate character Analogues organs birds wings, bats and insects (analogus)/convergent evolution Redundant  Correlated Characters Phyletic correlation High weight Higher genetic contents Diagnostic characters of Deuterostomes and Chordates (concordance)----phyletic correlation—evolutionary related END Principles of Systematics Module# 38 Principles of Systematics High Weight Characters High Weight Characters High weight characters Complexity Constancy Consistency Not affected by ecological shift Apomorphy Not a specific adaptation e.g. Morphological and behavioral character High Weight Characters Complexity Complexity-Genetalia Deep genetic character Higher complexity-higher weight age Constancy Character which is constant in a large group of species than variable character (Darwin 1859) According to Farris (1969) Low phenotypic variability be given high weight High Weight Characters Consistency A character which is consistently present in one group and consistently absent in related groups should have high weight  High Weight Characters Not affected by ecological shift A character that no change with ecology A bird feeding on fish in one habitat continue to feed on fish https://www.google.com/search?q=mergansers& in another habitat sxsrf=ALeKk03jIyrLE0TeIgIBxO6mWo9hBiogvg:16 03685582863&source=lnms&tbm=isch&sa=X&ve d=2ahUKEwjdtv2rstHsAhXvDmMBHZtJBOcQ_AUo An example is adaptation of AXoECCYQAw&biw=1360&bih=657 mergansers (Mergus) for fish eating  High Weight Characters Apomorphy A novel evolutionary trait that is unique to a particular species and all its descendants and which can be used as a defining character for a species or group in phylogenetic terms. https://www.google.com/search? q=apomorphy&sxsrf=ALeKk03Y_tzp73qJK0Em_ Hence, the possession of feathers Bfingu_YHOxiw:1603614144234&source=lnms is unique to birds and defines all &tbm=isch&sa=X&ved=2ahUKEwjbjLGbqM_sA hWzShUIHdkiB1oQ_AUoAXoECCAQAw&biw=1 members of the class Aves. 360&bih=600#imgrc=GCYTyU7VcBY0LM Principles of Systematics Module# 39 Principles of Systematics Low Weight Characters Low Weight Characters Characters having less taxonomic importance Less phylogenetic content Not reliable Poor indicators of relationships Low Weight Characters Highly variable Characters (hairs, branching pattern of arteries) Monogenic and oligogenic characters (albinism) varies independently of other characters Low Weight Characters Regressive characters (loss of eyes, loss of wings, wing veins in insects, loss of teeth in mammals, loss of segments in segmented animals are unnatural. Loss may be due to environmental conditions (eye loss in cave, loss of digestive systems in parasitic tapeworms) Narrow specialization e.g. Physiological character  Low Weight Characters Not constant Not consistent Change with ecology Less complex e.g. Physiological character END Principles of Systematics Module# 40 Principles of Systematics Non-Genetic Variations Non-Genetic Variations Types of Non-Genetic variations Individual variations in Time Social Variations Ecological Variations Traumatic variation Post-morten variations Non-Genetic Variations Individual variations in Time Age variations Seasonal variations of individuals Seasonal variations of generations  Non-Genetic Variations Age Variations Animals pass through large numbers of juvenile or larvae which are quite different from adult. Immature stage of eel (Anguilla anguilla) were originally https://www.google.com/search?q=eel&sxsrf=A LeKk02QiXShlrI7phddXt7HPFtE0QOvmA:160330 described as Leptocephalus 9550565&source=lnms&tbm=isch&sa=X&ved=2 brevirosteris in 1856 ahUKEwihuefBucbsAhWPTN8KHUuJCQsQ_AUoA XoECDUQAw&biw=1360&bih=600#imgrc=eWSx Larval stages different from adult WZoTy-WYyM (Caterpillar and butterfly) Non-Genetic Variations Seasonal Variations of individuals Same animal may have different appearance in different parts of the year In arctic and sub-arctic birds there may be change from white winter dress to normal colour summer dress.  Non-Genetic Variations Rock ptarmigians (Lagopus muta) Gray and brown upper parts in summer White plumage in winter https://www.google.com/search?q=ptarmigan&sxsrf=ALeKk015nxwTbGZOdxCyoPYsK-TETw_DO A:1603517715139&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjH3bT-wMzsAhVoQEEAHabtBj EQ_AUoAXoECCcQAw&biw=1360&bih=600#imgrc=sK318okbBMjJj Principles of Systematics Module# 41 Principles of Systematics Individual Variations  Individual Variations European Starling (seasonal variation) Freshly molted bird of October is covered with white spots and all feathers show whitish margins In winter edges of feathers wear off https://www.google.com/search?q=european+starling+in+october &hl=en&sxsrf=ALeKk00lEQwoUE0nvDEAwcEeS_aFlcXkJg:16035189 50740&source=lnms&tbm=isch&sa=X&ved=2ahUKEwil7MvLxczsAh V4UhUIHTdZA0QQ_AUoAXoECBYQAw&biw=1360&bih=600#imgrc =nUnihAZz9S-NkM  Individual Variations European Starling In spring (beginning of breeding season) whole bird is glossy black without the mold of single feather https://www.google.com/search?q=european+starling+in+spring% 2C+glossy+black&tbm=isch&ved=2ahUKEwi6xauzxszsAhVC-4UKHZ h3BakQ2-cCegQIABAA&oq=european+starling+in  Individual Variations Seasonal variations of consecutive generations Seasonal plasticity These variations are called polyhenism. https://www.google.com/search? African butterfly Bicyclus q=bicycles+anynana+in+wet+season&tbm=isch&ved=2ahUKEwjQs K3DxszsAhULcxoKHfjYAKMQ2- anynana cCegQIABAA&oq=bicycles+anynana+in+wet+season&gs_lcp=CgNp bWcQAzoECCMQJzoHCAAQsQMQQzoECAAQQzoFCAAQsQM6AggA Eyespots on margins (ventral OgYIABAIEB5QyY0uWN6XL2CLmi9oAHAAeACAAegDiAGKRJIBCDIt MjEuOC4xmAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei side)---- in wet season =4cKTX5C8Novmafixg5gK&bih=600&biw=1360&hl=en#imgrc=zxM XuCnjPwLPSM Very small or No eyespot ---Dry season Principles of Systematics Module# 42 Principles of Systematics Social Variations Social Variations In social insects there are definite groups of individuals in a colony. Each type of individual in a colony perform specific function. For examples in a colony of Honey bee: Queen, males (drones) and workers, soldiers  Social Variations Social variations workers: All workers are females, product of fertilized eggs. They are in majority in the colony. May be from 10000 to 50,000 per colony. development. Projection of colony, food collection, feeding of queen, take END care of young ones, cleaning of hive etc Principles of Systematics Module# 43 Principles of Systematics Social Variations Social Variations Social variation in ants Ants live in complex social colonies. Queen: founder and leader of the colony. Primary goal is to populate colony. Lay thousands of eggs Queen chambers are deep within the colony for protection. Long life in some species upto 30 years. Social Variations Social variation in ants Drones: Only function is to fertilize female Die after fertilization Rarely encountered outside the colony Workers: Foraging and protection Sometime: queen lay eggs, winged male and females-Alates or reproductive.  Social Variations Social variation in ants After maturation leave the colony in swarms. Establish new colony END Principles of Systematics Module# 44 Principles of Systematics Ecological Variations Ecological Variations A. Habitat Variation B. Variations induced by climatic conditions C. Host determined variations D. Density dependent variations E. Allometric variations F. Neurogenic color variations Ecological Variations A. Habitat variation Populations of single species in different habitat are visibly different. Oyster in still water Round or broader Oyster in strong currents Narrow, elongated and usually straight  Ecological Variations A. Habitat variation Oyster in clean water on pebble Lower valve is deep and more or less sharply ribbed to acquire strength Not needed attachment is with perfectly flat surface Oyster in muddy area Valves are less commonly ribbed END Principles of Systematics Module# 45 Principles of Systematics Ecological Variations Ecological Variations B. Variations induced by climatic conditions Animals with phenotypic plasticity Variations with temperature, draught, cold etc.  Ecological Variations C. Host determined variations Braconid wasp, Apanteles flaviconchae spin white cocoons if reared from blue green caterpillars of Choliase philodice Golden cocoons if reared from yellow green caterpillars of same species. https://www.google.com/search?q=apenteles+flaviconchae&tbm=isch&ved =2ahUKEwjkg7Ob_czsAhUD8IUKHQs4BLsQ2- Principles of Systematics Module# 46 Principles of Systematics Ecological Variations Ecological Variations D. Density-Dependent variations When newly hatched nymphs of locust are reared under crowded conditions----Gregarious phase Less crowded condition--- Transitional phase Separate rearing---Solitary phase These phase differ in anatomy, colour and behavioral characteristics----distinct species  Ecological Variations E. Allometric variation Allometry results in misappropriate size of some structure in relation to rest of the body. This results in animals of different sizes----Allometric https://www.google.com/search?q=allometric+variations&t variability bm=isch&ved=2ahUKEwjjrbyKg83sAhXC4YUKHRKVBOwQ2-c CegQIABAA&oq=allometric+variations&gs  Ecological Variations F. Neurogenic variation It is colour change in response to environment. Chameleons have Chromatophores in three layers below their transparent skin. Xenthophors (Yellow) and erythrophores (red) in upper layer https://www.google.com/search?q=chameleon&sxsrf=ALeK Iridophores or guanophores (blue k03w9hngHVfxaApti0b4bszoZ9g-