1. CLASSIFICATION OF ORGANISMS

2. Biologists have classified nearly 2 million species Estimates range from 13 million to 40+ million The science of describing, naming, classifying organisms is called taxonomy Any particular group within a taxonomic system is called a taxon

15. Species Concept Species can interbreed to produce fertile offspring Variations in a population include individual variations, geographic variations, and variations in form (polymorphisms) Species: a population of individuals that interbreed and produce fertile offspring under natural conditions

18. Taxonomists use structure, function, biochemistry, behavior, genetic systems, evolutionary history to classify organisms Homologies are similarities and can either be structural or chemical

19. HOMOLOGOUS STRUCTURE Similar features that originate in a shared ancestor (derive from same embryonic structure) Can result from modifications that change an original feature to 2 extremely different types (wing and arm)

22. Modern Version Domain - 3 – Kingdom - 6 Phylum – 30 – 89 (??) –Class Order - Family - Genus - Species

23. Human Classification Kingdom: Animalia (common phyla) Phylum: Chordata (common class) Class: Mammalia (similar order, common characteristics) Order: Primates (similar family, distinctive anatomy and way of life) Family: Hominidae (similar genera) Genus: Homo (sp w/ similar characteristics) Species: sapiens (Homo sapiens = wise man) (Greek homo = same; Latin homo = man, from the Earth)

24. 6 Kingdoms Eubacteria Archaebacteria Protista Fungi Plantae Animalia

25. The 6 kingdoms Prokaryotes (Used to be 1 kingdom, Monera) – Archaebacteria – Eubacteria Eukaryotes – Fungi – Protista – Animal – Plantae

26. Overview of the 6 kingdoms Archaebacteria – Unicellular – Live in extreme environments – Prokaryotic Eubacteria – Unicellular – Prokaryotic – “Common bacteria”

27. Overview of the 6 kingdoms Protista – Eukaryotic – Unicellular or colonial – Lots of different life styles Fungi – Cell walls made of chitin – Eukaryotic – Multicellular – External heterotrophs

28. Overview of the 6 kingdoms Plantae – Eukaryotic & Multicellular – Cell walls made of cellulose – Autotrophic Animalia – Eukaryotic & Multicellular – No cell walls – Internal heterotrophs

35. Prokaryotes vs. Eukaryotes Cell structure is extremely important in categorizing Prokaryotes are single-celled organisms that have no nucleus or other membrane-bound organelle (found in Domain Bacteria and Archaea) Eukaryotes are cells that have a nucleus and other membrane-bound organelles

40. Taxonomy Science of grouping organisms Aristotle grouped organisms into 2 categories: plants and animals In the 1730’s Carl Linne (Carolus Linnaeus) developed a system of taxonomy called binomial nomenclature

41. Carolus Linneaus (Carl Linne) Devised taxonomic system using hierarchal categories, and devised binomial nomenclature to identify species; Physalis amno ramosissime ramis angulosis glabris foliis dentoserratis was changed to Physalis angulata (ground cherry) Homo sapiens, Chaos chaos,

42. Chaos chaos The Pelomyxa or Chaos chaos is a very large protozoan and belongs to the Phyllum Sarcodina.

43. Binomial nomenclature Names usually describe organism, location; can be used to honor scientist or friend (or in some cases to insult individuals)

44. Phylogeny Phylogeny is the evolutionary history of a species (or taxon) Morphology, embryonic development, genetics, and fossil evidence all used to build phylogenetic trees Use of dichotomous key (written set of choices)

45. Cladistics Phylogenetic analysis that uses shared characters and derived characters Shared characters are features that all members of a group have in common (all mammals have mammary glands / all birds have feathers) Derived characters are those features that evolved only within the group under consideration (only animals (living/fossil) with feathers are birds)