Classification and Kingdoms Classification 1 Scientists have identified

Classification and Kingdoms

Classification 1. Scientists have identified more than 2 million species of organisms on earth, but have estimated that there a total of 40 million that actually inhabit the earth. So, how do we classify new species that are discovered?

Purpose of a Classification System 1. 2. Assign a single universal name to each organism Place organisms into groups that have real biological meaning

Taxonomy Field of biology that studies the classification of organisms Names and groups organisms according to their characteristics and evolutionary history A universal system is necessary to have clear communication among scientists 1. 2. 3. a) Eliminates the use of common names and confusion

Classification History Aristotle – 2, 000 years ago 1. a) Grouped animals into Land Dwellers, Water Dwellers, and Air Dwellers i. ii. b) What about caterpillars butterflies? Where should they be classified? What about frogs? Grouped plants into 3 categories, based on differences in their stems.

Classification History Carl Linnaeus – mid-1700’s 2. “Father of Modern Taxonomy” Developed a hierarchy that is the basis of Modern Taxonomy a) b) Hierarchy goes from broad to narrow i. c) d) Used morphology (form and structure) to classify organisms Developed a system of groups called TAXA i. e) Categories in which related organisms are placed First divided all organisms into 2 groups (kingdoms) i. ii. Plantae Animalia • What about bacteria? Fungi? Where do they fit?

Binomial Nomenclature Seven levels of modern classification (Linnaeus had five – K, C, O, G, S) 1. a) b) c) d) e) f) g) Kingdom Phylum Class Order Family Genus Species Broadest – most inclusive Narrowest – most exclusive King Phillip Came Over For Grandma’s Soup

Binomial Nomenclature Kingdom level is the largest/most general group. It is the most INCLUSIVE group (includes the most organisms). Species level is the smallest/most specific level. It identifies the specific organism. It is the most EXCLUSIVE group (includes the fewest organisms).

Binomial Nomenclature a) b) c) “Two-word naming” Use the genus and species for scientific naming (genus is written 1 st, species written 2 nd) i. e. , for humans: Homo sapiens (italics when typing, underline when writing; always capitalize the genus name, but never the species name)

Classification of the Grizzly Bear Kingdom - Animalia Phylum - Chordata Class - Mammalia Order - Carnivora Family - Ursidae Genus - Ursus Species – Horribilis The scientific name… Ursus horribilis

Binomial Nomenclature Why do we have Binomial Nomenclature? England – robin North America – robin Erithacus rubicula Turdus migratorius E. rubicula T. migratorius B. N. avoids confusion - different animals with same name

Binomial Nomenclature Sand dollar Seahorse B. N. avoids confusion - Confusing names

Binomial Nomenclature Puma, cougar, or mountain lion? Felis concolor B. N. avoids confusion - one animal with many names

Binomial Nomenclature Species Two organisms are the same species if they can breed and produce fertile offspring. Felis domesticus Felis concolor Which two are the same species?

Modern Phylogenetic Taxonomy Phylogeny – the study of evolutionary relatedness among various groups of organisms

Modern Phylogenetic Taxonomy Considerations Modern Taxonomists Take to Yield Reliable Information About an Organism’s Phylogeny 1. Fossil Record 2. Morphology 3. Embryological Development 4. Chromosomal Characteristics 5. Nucleotide and Amino Acid Sequences – Molecular Biology

(a) Fossil Record 1. 2. Fossil record often provides clues to evolutionary relationships. The fossil record may provide the framework of a phylogenetic tree, but a systematic taxonomist would seek to confirm the information it provided with other lines of evidence.

(b) Morphology 1. Taxonomist s study an organism’s morphology and compare it with the morphology of other living organisms.

(c) Embryological Patterns of Development 1. 2. Early patterns in embryological development provide evidence of phylogenetic relationships They also provide a means of testing hypotheses about relationships that have been developed from other lines of evidence.

(c) Embryological Patterns of Development 1. 2. 3. The blastopore will develop into an opening of the digestive tract. In echinoderms and chordates the blastopore becomes the anus. In all other animals the blastopore becomes the mouth. This leads to the conclusion that vertebrates and echinoderms are more closely related.

Chromosomal Comparison Counting and comparing chromosome shapes MAY be used to determine if two species are closely related. Chromosomes of humans and chimpanzees are surprisingly similar. 1. 2. a) b) Humans have 46; chimps have 48. Think about this, a deer mouse also has 48 chromosomes.

Chimp vs. Human Chromosomes 1. 2. Notice that many genes (colored sections) on both human and chimp chromosomes line up. At some point during evolution, chromosome 2 split in chimpanzees resulting in an extra chromosome pair.

Biochemical Comparison 1. Biochemistry is the study of the chemical processes and transformations in living organisms. 2. This includes comparing DNA, RNA, and proteins to determine relatedness. 1. For example, the hemoglobin amino acid sequences in humans and chimps are very similar

Modern Phylogenetic Taxonomy Systematic 1. a) Phylogenetic Tree i. Shows relationships thought to exist among groups of organisms ? ?

Modern Phylogenetic Taxonomy

Modern Phylogenetic Taxonomy Cladistic 2. a) Cladograms i. New system of phylogenetic classification, uses certain features of organisms – DERIVED CHARACTERISTICS

Modern Phylogenetic Taxonomy

Modern Classification 1. Another feature that is considered in classification are homologous features, features that have similar structure and come from similar embryonic layers but have completely different functions

Modern Classification 1. Analogous features are ones that come from different embryological development but look similar and perform similar functions, like the wings of bats and the wings of insects.

Six-Kingdom System Modern taxonomists recognize that many organisms are neither plants nor animals, so they use the six - kingdom system. 1. a) Kingdoms group organisms together that have similarities in such fundamental characteristics i. iii. Major cellular structure Methods of obtaining nutrients Metabolism

Six Kingdoms Archaebacteria (“archae” – ancient) 1. a) b) c) d) e) May be directly descended from and very similar to the first organisms on earth Unicellular prokaryotes with distinctive cell walls without peptidoglycan; no nucleus Some are autotrophic, producing food by chemosynthesis, while others are heterotrophic Lives in harsh environments such as sulfurous hot springs, very salty lakes, and in anaerobic environments Include chemosynthetic bacteria, marine microbes, zeikus

Six Kingdoms Eubacteria (“eu” – true) 2. a) b) c) d) Unicellular prokaryotes Have cell walls made of peptidoglycan Both autotrophs and heterotrophs – (mostly hetero) Include disease-causing bacteria that cause ailments like tooth decay. Eg. Botulism, e-coli, anthrax

Six Kingdoms Monerans – original name of both Archaebacteria and Eubacteria. • • These combined kingdoms have the greatest number of organisms on earth. Both reproduce by binary fissions, but do have some ways of recombining genetic information allowing for evolution

Six Kingdoms Protista (“ash and trash” kingdom) 3. a) b) c) d) All eukaryotes that are NOT plant, animal, or fungi Have cell walls; some have chloroplasts Unicellular, and some Multicellular Include Euglena and amoebas, protozoan, paramecium

Six Kingdoms Fungi 4. a) b) c) d) e) Multicellular eukaryotes Have cell walls that contain chitin Heterotrophic and obtain their nutrients by releasing digestive enzymes into a food source Act either as decomposers or as parasites in nature. Includes molds, mildews, mushrooms, and yeast.

Six Kingdoms Plantae 5. a) b) c) d) e) Multicellular eukaryotes Most are autotrophic Have cell walls that contain cellulose. Cells are specialized for specific functions, such as photosynthesis, transport of materials, and support. Includes mosses, ferns, cone-bearing plants (gymosperms) and flowering plants (angiosperms)

Six Kingdoms Animalia 6. a) b) c) d) e) Multicellular eukaryotes Heterotrophic No cell walls Are mobile, but some are permanently attached to surfaces (sponges and barnacles) Includes fish, birds, reptiles, amphibians, mammals, sponges, jellyfish, worms, sea stars, insects, man

Six Kingdoms

Taxonomic Kingdoms of Life

Domains Used to group kingdoms together 3 Domains 1. 2. a) Bacteria i. b) Archae i. c) Composed of prokaryotic-celled organisms Eukarya i. Composed of eukaryotic-celled organisms

Domains

Domains