1. Classification 5.3

2. The Binomial System of Names for Species Binomial Nomenclature - Binomial Nomenclature - A two part Latin or Greek name for each species and a hierarchy, or ordering, of species into broader and broader groups – assigns a 2-part name, to each organism 1 st Part – the genus the species belongs and always capitalized 2 nd Part – one species within the genus and begins with a lower case letter - Both are written in italics when typed or underlined when written by hand

3. The Binomial System of Names for Species Most words are Latin or Greek in origin Genus Species

4. The Binomial System of Names for Species Developed by Swedish botanist Carolus Linnaeus (1707- 1778) Not the first to use the idea of genus & species it was made popular in his book: Systema Naturae 1735 Using this system and the associated rules ensure: That each organism has a unique name Names can be universally understood Stability to the system (can’t just change a name)

5. Taxonomy and Evolution Taxonomy Taxonomy – (a branch of Biology) involves the identification, naming, and classification of species To reduce confusion in discussing organisms Trying to make sense of the environment Showing evolutionary Links Predicting characteristics shared by members of a group One goal of taxonomy is to assign a universal scientific name to each known species

6. Hierarchy of Taxa Taxa (Taxon) – Refers to the categories that scientist have generated names for. Category examples include for example: Plants Conifers Spore producing plants etc. The hierarchy of taxa is used to classify species into many subcategories that are found within larger categories There are specific names for these categories

7. Domains 1.Archaea – single celled organisms These are ancient organisms, distinct from bacteria Extremophiles – archaeans that prefer extreme temps Thermophiles – Heat loving Methanophiles – Methane loving Halophiles – salt loving 2.Eubacteria – bacteria you are familiar with 3.Eukaryote – all other life Cells have membrane bound nucleus and membrane bound organelles

8. Seven Principal Taxa System was established because of the hundreds of thousands of different plant and animals So each domain is subdivided into these: Kingdom Phylum Class Order Family Genus Species King Phillip Came Over For Good Soup

9. Other Classifications By feeding habits: Carnivore/Herbivore By habitat: land dwelling/aquatic By daily activity: nocturnal/Diurnal By risk” harmless/venomous By anatomy: vertebrae/ invertebrate One of the objectives of classification is to represent how living (and extinct) organisms are connected In a natural classification, the genus and accompanying higher taxa consist of all species that have evolved from one common ancestral species. What is important when classifying is be consistent, logical, easily implemented, and there is a consensus

10. Five Kingdoms Most widely accepted system Kingdom Plantae – plants (cactus to moss) Kingdom Animalia – animals Kingdom Fungi – fungi and mold Kingdom Protoctista – protozoa and algae Kingdom Prokaryotae – the bacteria

11. Reclassification Linnaean classification was limited to observable characteristics No knowledge of genetics Taxonomist sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species. Page 247: Read about the reclassification of the blue wood aster

12. Natural Classification Natural Classification – uses ancestry to group organisms together Artificial Classification – the use of arbitrary characteristics, like taste, or use in industry, etc

13. IB Requires: Classification of one plant and one animal species from Domain to Species Level Domain: Eukaryote (both plants and animals) Kingdom: Animalia (animals) Plantae (plants)

14. Example of Plant Phyla 4 Phyla Most Familiar: 1.Bryophyta – includes plants of very short stature (moss) 2.Filicinophyta – Ferns and Horse tails 3.Coniferophyta – Conifer phylum (cedar & pine trees) 4.Angiospermophyta – include all flowering plants which have their seeds surrounded by fruit

15. For Example Animal Phyla Six Invertebrate Animal Phyla 1.Porifera Sponges – very simple marine animals Sessile – stuck in place They do not have mouths or digestive tracts They feed by pumping water through their tissues to filter out food No muscle or nerve tissue or distinct internal organs

16. For Example Animal Phyla 2.Cnidarians Corals, sea anemones, jellyfish, hydra, floating colonies (Portuguese man-of-war) Nematocysts – stinging cells One characteristics common to all in this group Some are sessile others are fee – swimming or float using currents Catch food with their tentacles and they have a gastric pouch with one opening

17. For Example Animal Phyla 3.Platyhelminthes Flatworms They have only one body cavity A gut with one opening for food to enter and waste to exit No heart or lungs Tapeworm

18. For Example Animal Phyla 4.Annelida Segmented worms Earthworms, leeches, and polychaetes Bodies are divided up into segments separated by rings They have bristles on their bodies (not always visible) They have a gastric tract where they have a mouth on one end and intestines and an opening on the other end where waste are released polychaetes

19. For Example Animal Phyla 5.Mollusca Most are aquatic Snails, clams, and octopuses Produce shells using calcium Bodies are not segmented 6.Arthopoda Have a hard exoskeleton made with chitin, segmented bodies, and limbs that are jointed Limbs can be used for walking, swimming, are eating Spiders, insects, scorpions, and crustaceans (crabs & shrimp) Over a million different species all over the world

20. For Example Animal Phyla 7. Chordata These are your vertebrates, the animals that have a backbone. These are all organisms that at some point developed a notochord during their development Fish Amphibians Reptiles Birds mammals

21. Using A Dichotomous Key 1.You look at the first section of the key which has a pair of sentences describing a characteristic 2.Next, you look at the organism to see if the particular characteristic described in the first line is present in the organism 3.If the answer is yes, then go to the end of its line and find the number of the next pair of statements to look at, follow the number given and continue until the end 4.Keep going until the end of the line has a name instead of a number If you have answered each question correctly, that will be the name of your organism Go to page 254 – 255;

22. Using A Dichotomous Key

23. Cladistics 5.4

24. Characteristics used for Classification Used to help botanist and zoologist how to classify organisms Morphology – shape (like a seed or a birds bill) Anatomy – number of pedals on a flower or type of digestive system Cytology – the structure of cells and their function Phytochemistry – special organic compounds that only plants can make, often to protect themselves from attack by insects Chromosome Number - Two species with the same chromosomes number are more likely to be closely related than those with differing numbers Molecular Differences – Proteins and DNA sequences differ between one species and another Molecular Systematics – classifying organisms using molecular differences

25. Clades Cladistics – a system of classification that groups taxa together according to the characteristics that have evolved most recently. Cladistics is an example of natural classification

26. Biochemical Evidence of Clades Biochemical evidence include DNA and Protein structures All living organisms on Earth use DNA All protein found in living organisms use the same 20 amino acids to form their polypeptide chains Evidence for which species are part of a clade can be obtained from the base sequence of a gene or the corresponding amino acid sequence of a protein.

27. Phylogeny Phylogeny – the study of the evolutionary past of a species By looking at the polypeptide sequences of certain proteins in different groups of animals, it is possible to trace their common ancestry. Done with hemoglobin, mitochondrial proteins, and chlorophyll Advances in DNA sequencing the study of nucleic acid sequences in an organisms DNA, as well as mitochondrial DNA, has been effective in stablishing Biochemical Phylogeny Changes in DNA sequences of genes from one generation to another are due to mutation. The more differences the less related: 1.AAAATTTTCCCCGGGG 2.AAAATTTACCCCGGGG 3.AAAATTTACCCGCGGG 4.AACATCTACCAGCCTG

28. The Evolutionary Clock Differences in polypeptide sequences accumulate steadily and gradually over time as mutations occur from generation to generation in a species. Changes can be used to estimate how far back in time 2 related species split from a common ancestor Mitochondrial DNA is used because it is passed directly from mother to offspring and the only changes would be mutations (no meiosis)

29. Analogous and Homologous Traits Homologous Characteristics – are derived from the same part of a common ancestor 5 finger limbs Eyes DNA – combinations of base pairings that lead to certain proteins Analogous Characteristics – have the same function but they do not have the same structure and they are not derived from a common ancestor. Wings – different from bird to bat, from insect Sharks and dolphins have pectoral fins – one is a fish the other a mammal

30. Analogous and Homologous Traits

31. Cladograms Cladogram Cladogram – tree diagrams that show the most probable sequence of divergence in clades Node – place where a speciation happened and where the common ancestor was found Cladistics attempts to find the most logical and most natural connections between organisms in order to reveal their evolutionary past. Evidence from cladistics has shown that classification of some groups based on structure did not correspond with the evolutionary origins of a group or species

32. Cladograms Clades Clades – each evolutionary branch in a cladogram Clades can nest within larger clades Each item in a clade may be an individual species genus, a family or other taxonomic group

33. Cladograms