Diversity of Living Things

1. Diversity of Living Things

2. Where Earth’s diversity exists • All life is found within a layer around the Earth called the biosphere. The biosphere includes anywhere that life exists – including the land, water and air. • The biosphere is about 16km thickand accounts for very little of the planet’s actual mass.

3. Number of species on Earth • Biologists estimate that there are between 30 million to 100 million different species within the biosphere, yet, only 1.75 million have been identified and described. • How many can you name?

4. Why Classify? • Humans have developed classification systems in order to make sense of the abundant biological diversity that exists in nature.

5. Taxonomy …the science of naming organisms and assigning them to groups

6. Chordata The Classification System • The system is hierarchical. • Larger groups are more general and smaller groups are more specific. • For example, the phylum Chordata includes both lions and lionfish, but the genus Panthera includes only lions.

7. The Classification System • The system is phylogenetic. • It is meant to reflect the evolutionary interrelatedness among groups. • For example, the grey wolf and the dog both are placed in the genus Canis because of their close evolutionary relationship.

8. Eight Levels of Taxonomic Classification • Domain • Kingdom • Phylum • Class • Order • Family • Genus • Species

9. How will I remember the order? • The sentence “Dear King Philip Came Over For Green Soup" represents the order of taxonomic categories, from the most general to the most specific.

10. Domain • According to this system of classification, there are three domains: • Bacteria • Archea • Eukarya

11. Bacteria and Archaea • All organisms are microscopic • All organisms are unicellular • Cells lack a nucleus • Cells lack membrane bound organelles • They are called prokaryotes

12. Eukarya • Cells contain a nucleus • Cells contain membrane bound organelles • Cells are eukaryotic

14. A New Domain : Archaea • In the late 1970s Dr. Carl Woese and his colleagues shocked the scientific community by the discovery of an entirely new group of organisms • They were studying relationships among the prokaryotes using DNA sequences, and found that there were two distinctly different groups.

15. Archaea • Those "bacteria" that lived at high temperatures or produced methane were distinctly different from the usual bacteria and the eukaryotes. • Woese proposed that life be divided into three domains: Eukaryota, Bacteria, and Archaea

16. Archaea • Archaeans include inhabitants of some of the most extreme environments on the planet. They are known as extremophiles: •thermophiles, live at high temperatures •hyperthermophiles, live at really high temperatures (present record is 121°C) •psychrophiles, like it cold (one in the Antarctic grows best at 4°C) •halophiles, live in very saline environments (like the Dead Sea) •acidophiles, live at low pH (as low as pH 1 and who die at pH 7) •alkaliphiles, thrive at a high pH.

17. Basic Archaeal Shapes : Far left: Methanococcus janaschii, a coccus form with numerous flagella attached to one side. At left center, Methanosarcina barkeri, a lobed coccus form lacking flagella. At right center, Methanothermus fervidus, a short bacillus form without flagella. At far right, Methanobacterium thermoautotrophicum, an elongate bacillus form. http://www.ucmp.berkeley.edu/archaea/archaeamm.html

18. Domain: Bacteria • Is composed of organisms that are much more common than Archaea and live almost anywhere. • There are more bacteria in a person's mouth than there are people in the world. • Many are decomposers, some are photosynthesizers, and a few cause disease. • There are many shapes that bacteria can come in, but three of the main ones are cocci, bacilli, and spirochete.

19. Domain: Eukarya • The Domain Eukarya arose from the first prokaryotic organisms more than 1.7 billion years ago. • It includes all of the organisms with eukaryotic cells--that is, those with membranous organelles (including mitochondria and chloroplasts).

20. Domain: Eukarya • Members of the domain Eukarya have the following characteristics: • Eukaryotic cells • Unicellular (some Protists and yeasts), Colonial (some Protists) or Multicellular (most Fungi, Plantae, and Animalia) organisms • Cell division by mitosis, with a variety of cycles of reproduction and recombination • A variety of modes of access to energy and carbon, varying with kingdom

22. Kingdom • Most biologists currently recognize six different kingdoms: Archaebacteria, Eubacteria, Protists, Fungi, Plants, Animals

24. Phylum (plural: phyla) • Each kingdom is subdivided into smaller, more specific groups called phyla.

26. Class • Each phylum is subdivided into smaller groups called classes.

28. Order • Each class is subdivided into smaller groups called orders.

30. Family • Each order is subdivided into smaller groups called families.

32. Genus (plural: genera) • Each family is subdivided into smaller groups called genera.

34. Species • Each genus is subdivided into smaller groups called species. • The species is the most specific level of classification.

36. The Linnaean System of Classification • Swedish scientist Carolus Linnaeus (1707-1778), is the father of the modern system of classification known as binomial nomenclature

37. The Linnean System of Classification • According to this system, every animal or plant is given a scientific name consisting of two words. • The first word refers to name of the genus while the second word refers to the name of the species

38. What is this animal? Cougar? Panther? Mountain Lion? Puma?

39. Avoiding confusion • Binomial nomenclature avoids the confusion of using common names. • For example, the mountain lion is commonly called puma, cougar, panther in different parts of the world. • Scientists all over the world recognize this animal by a scientific name Felis concolor.

40. What Is a Genus? • The taxonomic classification lower than ‘family’ and higher than ‘species’. • In other words, genus is a more general taxonomic category than is species. • A group of related species demonstrating common characteristics.

41. What is a Species? • A species is a group of organisms that share many physical and physiological traits and are capable of freely interbreeding (mating) in the wild and producing viable offspring.

43. International Council for Binomial Nomenclature (ICBN). Guidelines for Naming 1. Every scientific name should have words that use Latin grammatical forms but may use other languages. 2. The first word refers to name of the genus and the second word to the name of the species. 3. The name of the genus should start with a capital letter and name of the species with a small letter. 4. Both the names should be printed in italics or else they should be underlined separately. For example, Felis leo or Felisleo.

44. Felis tigris Felisconcolor Felis domestica Felisleo

45. Systematic Position • Once an organism is identified and grouped, it is then described in terms of the various taxonomic categories to which it belongs. • Such a description is known as systematic position.

46. Type Specimens • Type specimens are selected by the taxonomist to designate individuals which typify the described species. • Type specimens are placed in museums for study by taxonomists. • Often the type specimen does not represent all the variation within a species.

48. Systematic Position • The following is a description of the systematic position of human being and the hibiscus plant.