1. Warmup Complete the sentences: 1) Separate species… 2) Speciation happens when… 3) It is different than genetic drift in that…

2. DECEMBER 15 TH 2010

3. Learning Goals Be able to use and create a dichotomous key to identify organisms. Relevant Standard: Students know how to construct a simple branching diagram to classify living groups of organisms by shared derived characteristics, and expand the diagram to include fossil organisms. Be able to describe recent evolution resulting in modern humans.

4. Dichotomous Key Dichotomous Keys are used to classify organisms based on only a few observations. They use simple “either or” questions, and based on the answer to the question redirect you either to another question or the scientific name of the species. Good dichotomous keys are both easy to use and reflect how species are related according to evolutionary branching tree diagrams (phylogeny).

5. Guided Practice 1. Has pointed ears - go to 3 Has rounded ears - go to 2 2. Has no tail - Kentuckyus Has tail - Dakotus 3. Ears point upward - go to 5 Ears point downward - go to 4 4. Engages in waving behavior - Dallus Has hairy tufts on ears - Californius 5. Engages in waving behavior - WalaWala Does not wave - go to 6 6. Has hair on head - Beverlus Has no hair on head (maybe on ears) - go to 7 7. Has a tail - Yorkio Has no tail, aggressive – Rajus The genus is “Nornos”. Find the full scientific name for each organism using the dichotomous key. A) B) C) D)E)F) G)

6. Guided Practice Solutions A)Nornos WalaWala B)Nornos Californus C)Nornos Rajus D)Nornos Kentuckyus E)Nornos Dallas F)Nornos Beverlus G)Nornos Yorkio http://www.biologycorner.com/worksheets/dichoto.html

7. Independent Practice Human Chimpanzee Gorilla Orangutan Gibbon Create a dichotomous key for some common hominids.

8. Independent Practice Trade dichotomous keys with a partner and see if they are useful for identifying these two hominids:

9. Main Fossil Sequence SpeciesTime Bipedal Upright Tool Use Language Use Brain Size Ardipithecus Ramidus 5.6  4.5M X300-350 cm 3 Australopithecus Afarensis 3.9  3.0M XX380-430 cm 3 Australopithecus Africanus 3.0  2.3M XX400-500 cm 3 Homo Habilis 2.5  1.6M XXX590-650 cm 3 Homo Erectus 1.7  0.2M XX+X850-1200 cm 3 Homo Sapiens 0.2M  XX+X1200-1450 cm 3

10. Noteworthy: “Lucy” and “Ardi” Walking upright developed early on. Brain size and tool use developed simultaneously. Increased brain development meant more child-care, which meant more opportunity to educate/culture offspring. True language use developed last. The common ancestor w/ chimpanzees is estimated to be 5M  8M old. The common ancestor w/ a chimpanzee is not the same as a modern chimpanzee.

11. Monogenesis Theory vs. Multiregional Theory Recall the difference between genetic drift and speciation. The Multiregional Theory states that modern humans evolved in parallel in multiple parts of the world. They presumably interbred which reduced genetic diversity to its present level. The “Java Man” and the “Neanderthal Man” contributed genes to the modern Homo Sapiens. The Monogenesis Theory states that multiple migrations originated in Africa, where each wave outcompeted previous waves and gradually replaced populations such as the “Java Man” and “Neanderthal”. While some interbreeding is possible, it was not a significant factor. More evidence favors the Monogenesis Theory.