Classification of Living Things

1. Classification of Living Things Taxonomy and Cladograms

2. What is Taxonomy? • For millennia humans have created different ways to describe the living things on our planet. • At first our attempts to organize and classify animals were simple and based solely on their external appearance. • We now use a more complex system.

3. Why Do We Need to Classify Things? • The main reason is that knowing which species are related to each other, and how closely they are related, is very useful to the Scientific community. • If you were trying to find out what was wrong with a whale it would be useful to know that it is a mammal and not a fish.

4. Carolus Linnaeus

5. Carolus Linnaeus 1707 - 1778 • Every recognized species on Earth is given a two-part scientific name. This system is called "binomial nomenclature." • Carolus Linnaeus (1707–1778) introduced the concept of binomial nomenclature in his great work called Systema Naturae. • In this book, nature was divided into three kingdoms: mineral, vegetable, and animals. • Linnaeus also established five ranks: class, order, genus, species, and variety.

6. Taxonomic Hierarchy • A Taxonomichierarchy is very similar to a family tree. • Through it you can track how closely related each species is to each other. • Depending on how detailed you wish to be, this can be a simple tree chart, or a complex one (tolweb.org is an example of a complex one).

7. Do Kings Play Chess On Fine Glass Surfaces? • This year you will be responsible to remember the following taxonomic hierarchy: • Domain (Do) • Kingdom (Kings) • Phylum (Play) • Class (Chess) • Order (On) • Family (Fine) • Genus (Glass) • Species (Surfaces)

8. So How Does It Work? • Each level of the hierarchy has several groups and these groups each have specific characteristics required to be part of them. • If we found a new living organism we would compare its characteristics to these groups to see where it fits. • If it was endothermic (warm blooded), fed its young milk, had hair and gave live birth we would probably classify it as a mammal.

9. We Just Keep Learning • Since Linnaeus we have continued to add new groups to the taxonomic hierarchy. • As we continue to learn and develop new tools for investigation (like DNA analyses) we often have to change how we describe an organism from a taxonomic point of view.

10. Domain: Eukarya Kingdom: Animalia Phylum: Chordate Class: Mammalia Order: Primates Family: Pongidae Genus: Pan Species: troglodytes Domain: Eukarya Kingdom: Animalia Phylum: Chordate Class: Mammalia Order: Carnivora Family: Felidae Genus: Panthera Species: leo Chimpanzee vs. Lion

11. Comparative Taxonomy • By comparing the Chimpanzee to the Lion we can see that though they are very different creatures, they have some key things in common. • Both are animals with chordates (vertebrates) and mammals. • Yet one is a primate (apes and monkeys) and the other a carnivore (meat eaters). • Evolutionists use these similarities and differences to determine the relationships between species.

12. Broad to Specific • Each level of the taxonomic tree gets more and more specific. • Domain, Kingdom, Phylum and Class are very large groups with broad characteristics (we’re mammals too). • But by the time you get to Genus and Species the characteristics get very specific. See the next slide.

13. Domain: Eukarya Kingdom: Animalia Phylum: Chordate Class: Mammalia Order: Carnivora Family: Felidae Genus: Acinonyx Species: jubatus Domain: Eukarya Kingdom: Animalia Phylum: Chordate Class: Mammalia Order: Carnivora Family: Felidae Genus: Panthera Species: leo Cheetah vs. Lion

14. Comparative Taxonomy 2 • As you can see the cheetah and lion share more in common than the lion and chimpanzee did. • Yet despite both being Felidae (cats) they are each part of a different Genus and a unique species. • The Species level is very specific.

15. Scientific Names • Each living creature on our planet has been given a Scientific name in Latin. • The Genus and Species of a creature are combined to create the Scientific name (thank you Linnaeus). • Panthera leo – lion • Acinonyx jubatus - cheetah

16. Why Latin? • Each living creature on the planet has several names. A lion is known as a leone in Italian and an ingonyama in Zulu. • This could lead to confusion amongst our world’s scientists. • Since Latin is a dead language, meaning it will never change as it is not actively spoken, scientists use it to name things. • This name means the same thing, no matter where you are on Earth.

17. Cladograms

18. Cladograms • Cladograms are tree-like charts that generally show the evolutionary relationships between different creatures or taxonomic groups. • They can be drawn artistically, simply, or extremely complexly (tolweb.org).

19. Basic Cladogram for Great Apes Gorilla Chimpanzee Bonobo Human Orangutan

20. Interpreting a Cladogram

21. Interpreting a Cladogram • Some cladograms give extra details. • The one above showed that all three creatures possessed a backbone as they come after the trait. • However only the horse and human shared the placenta characteristic. • Thus humans are more closely related to horses than to fish in an evolutionary sense.

22. Resources • www.hawaii.edu • www.torontozoo.com • www.nationalzoo.si.edu • www.tolweb.org