Classification of Organisms

1. Classification of Organisms

2. Classifying Organisms • One important branch of biology investigates biodiversity, the variety of organisms considered at all levels from populations to ecosystems. • Since the early 1980’s Terry Erwin & others have been working to catalog insect species in plots of tropical rain forest • They fog the treetops with insecticide & catch the falling insects in a net

3. A way of grouping objects together based on similarities In the beginning---plants were grouped based on people who ate them— Edible Non-edible The history of the Tomato-1820 Colonel Robert Gibbon Johnson announced that at noon on September 26, he would eat a basket of tomatoes in front of the Salem NY courthouse—aka “love apple” Classification is…

4. Scientists Who Developed Classification

5. Developed 1st method of classification Classified into 2 major groups Plants: herbs, shrubs or trees Animals: According to where they lived: land, water or air Aristotle: Greek Philosopher

6. Swedish naturalist Methods still used today Selected physical characteristics based on close relationships of organisms Each category represents a level of grouping from larger, more general to smaller, more specific categories Plants: based on reproductive structures Animals: based on evolutionary traits Carolus Linnaeus

7. Invented the 2-word naming system to identify species called BINOMIAL NOMENCLATURE: Bi (2) Nomial (name) Scientific Name: Genus: 1st word: consist of closely related species Species: 2nd word: consist of description of the species. Carolus Linnaeus

8. Genus is ALWAYS capitalized & is 1st Species is ALWAYS lowercase & is 2nd BOTH ARE ITALICIZED OR UNDERLINED!!! Homo sapiens Felix tigerus F. leo F. domestica RULES OF BINOMAL MONEMCLATURE

9. SPECIE • Species names come from Latin roots and are needed to be the same for all countries and in every language • The name of a species is often descriptive

10. Subspecies • Biologists refer to variations of a species that live in different geographic areas as subspecies • A subspecies name follows the species identifier

11. Subspecies: Alabama Beach Mouse This mouse is one of several subspecies of old field mice which live only in coastal sand dune areas. Living isolated from other beach mice for thousands of years has allowed each subspecies to develop its own slightly unique characteristics suited to its particular beach environment. Peromyscus polionotus ammobates Other Subspecies: Perdido Key beach mouse, Choctawhatchee beach mouse, Santa Rosa beach mouse, and St. Andrews beach mouse. They differ from the ABM and each other in coloration and body size

12. Scientific & Common Names Many organisms have common names that can be misleading. Example: a sea horse is a fish, not a horse. Also, it is confusing when a species has more than one common name.

13. Do not tell you how organisms are related or classified Can be misleading Confusion can occur when organisms have more than one name All newly discovered species are given Latin names because it is no longer used Common Names

14. Taxonomy is… • Taxonomy (tak SAH nuh mee) is the branch of biology that groups and names organisms based on studies of their different characteristics • Biologists who study taxonomy are called taxonomists

15. Taxonomists • Is a useful tool – if a child has eaten a mushroom & You do not know whether it is poisonous… • Important to the economy- often discover new sources of lumber, medicines & energy…

16. Organisms can be identified easily by using a dichotomous key Animals around the world use the same identification system A key is made up of sets of numbered statements. Each set deals with a single characteristic of an organism, such as leaf shape or arrangement Dichotomous Key

17. Using a dichotomous key to identify money!

18. Systematic • More than 200 years ago, Linnaeus grouped organisms according to similarities that he could readily see. • Modern biologists consider not only visible similarities, but also similarities in embryos, chromosomes, proteins, and DNA • Systematics is the classifying of organisms in terms of their natural relationships

19. Cladistics • In 1966, Willi Hennig developed cladistics, a system of phylogenetic analysis that uses shared or derived characteristics as the only criteria for grouping taxa

20. How are evolutionary relationships determined? • Evolutionary relationships are determined on the basis of similarities in structure, breeding behavior, geographical distribution, chromosomes, and biochemistry. • The presence of many shared physical structures implies that species are closely related and may have evolved from a common ancestor.

21. 1. Structural similarities • For example, plant taxonomists use structural evidence to classify dandelions and sunflowers in the same family, Asteraceae, because they have similar flower and fruit structures. • Taxonomists observe and compare features among members of different taxa and use this information to infer their evolutionary history.

22. 2. Breeding Behavior • Sometimes, breeding behavior provides important clues to relationships among species. • For example, two species of frogs, Hyla versicolor and Hyla chrysoscelis, live in the same area and look similar. During the breeding season, however, there is an obvious difference in their mating behavior. • Scientists concluded that the frogs were two separate species. Gray Treefrog Gray Treefrog

23. 3. Geographical Distribution Probing Bills Grasping Bills Crushing Bills Feeders Cactus Insect Feeders Seed Fruit Feeders Parrot Bills Feeders Ancestral Species

24. Geographical distribution • These finches probably spread into different niches on the volcanic islands and evolved over time into many distinct species. The fact that they share a common ancestry is supported by their geographical distribution in addition to their genetic similarities.

25. 4. Chromosomal Comparison • Both the number and structure of chromosomes, as seen during mitosis and meiosis, provide evidence about relationships among species. • For example, cauliflower, cabbage, kale, and broccoli look different but have chromosomes that are almost identical in structure. • Therefore, biologists propose that these plants are related.

26. Phylogenetic Classification: Models • The evolutionary history of a species is called its phylogeny (fy LAH juh nee). • A classification system that shows the evolutionary history of species is a phylogenetic classification and reveals the evolutionary relationships of species.

27. Cladistics • One biological system of classification that is based on phylogeny is cladistics (kla DIHS tiks). • Scientists who use cladistics assume that as groups of organisms diverge and evolve from a common ancestral group, they retain some unique inherited characteristics that taxonomists call derived traits.

28. Shared characteristics • Is a feature that all members of a group have in common • Example: hair in mammals or feathers in birds

29. Derived characteristics • Is a feature that evolved only within the group under consideration • Example: feathers are though to be a derived characteristic for birds b/c scientists hypothesize that feathers evolved only within the bird lineage and were not inherited from the ancestors that birds share with reptiles

30. Cladistics Allosaurus Velociraptor Robin Archaeopteryx Sinornis Theropods Feathers with shaft, veins, and barbs Flight feathers; arms as long as legs 3-toed foot; wishbone Down feathers Light bones

31. How are living things Classified? Felix tigerus

32. A group of organisms is called a taxon (plural, taxa The smallest taxon is species. Organisms that look alike and successfully interbreed belong to the same species. The next largest taxon is a genus—a group of similar species that have similar features and are closely related Order of Taxa Mountain lion

33. Order of Taxa • Kingdom, Phylum, Class, Order, Family, Genus, & Species Can you remember it this way? • King Phillip Came Over For Graduation Saturday. • Kings Play Chess On Fine Glass Surfaces.

34. Important Facts • Linnaeus version of hierarchy of organization was made of only 2 kingdoms-animals & plants • Modern biologists adopted his system, but added several other kingdoms, as well as domains (categories above kingdoms) • **there are 3 domains of life

35. Eukarya Domain Kingdom Animalia Chordata Phylum Class Mammalia Carnivora Order Family Felidae Genus Lynx Lynx canadensis Lynx rufus Species Bobcat Lynx

36. Introduction to Classification

37. The three domain names are Bacteria, Archaea, and Eukarya All living things seem to be related by ancestry to one of these 3 Domains of Life

38. Domain Bacteria • Is made of small, single-celled prokaryotic organisms • Usually have a cell wall & reproduce by cellular reproduction • Each bacteria has a cell wall, plasma membrane, cytoplasm (that lacks organelles) • Do not have a true nucleus • Oldest known fossils appear as bacteria

39. Domain Archaea • Consist of prokaryotes named Archaea • Have distinctive cell membranes, & genetic properties • Some are autotrophs • Some produce methane (as waste) • Many inhabit harsh environments (sulfur springs, deep-sea thermal vents, salty lakes…) • Thought to be the earliest organisms on Earth

40. Domain Eukarya • Most familiar group • Consist of eukaryotic organisms • Have true nucleus, complex cellular organelles • Include Plants, Animals, Fungi, and a variety of single-celled organisms

41. 6 kingdoms of life

42. Woese and the 6 Kingdoms • Biologists Carl Woese proposed in 1977 a 6-kingdom system that divided the then 5 kingdom into two new kingdoms; Archaebactera and Eubacteria • In 1990, Woese introduced the 3 domain system that is still used today

43. 6 Kingdoms of Life

44. Kingdom Eubacteria • Aligns with the domain Bacteria • Eubacteria means “true bacteria” because it distinguishes this group from archaea which are no longer considered to be bacteria Blue-Green Bacteria

45. Kingdom Archaebacteria • Aligns with the domain Archaea • Archaebacteria means “ancient Bacteria” • Are found in extreme habitats where there is usually no oxygen available Dead Sea Thermal Vents

46. Eukaryote that are not plants, animals or fungi. Unicellular organisms Examples are amoebas, paramecium, euglenas, Seaweed, Diatoms… Kingdom Protista

47. Unicellular or multi-cellular eukaryote that absorbs nutrients from organic materials in the environment There are around 70,000 species of fungi Include puffballs, mushrooms, rusts, smuts, mildew, and molds. Kingdom Fungi

48. Consist of eukaryotic, autotroph, multicellular plants that contain chloroplasts, use photosynthesis and have cell walls There are more than 250,000 known species of plants Kingdom Plantae

49. Animals are eukaryotic, multicellular heterotrophs that develop from embryos Most have symmetrical body organization & move around their environment to find food Nearly all are able to move from place to place. Animal cells do not have cell walls Kingdom Animalia

50. Future taxonomic systems • Because taxonomy systems are changing, modern biologists are suggesting changes for the now six-kingdom, three-domain system • Suggestions like subkingdoms…