Understanding Evolution: Homology and Analogy
Open up this website: http://evolution.berkeley.edu/evolibrary/
'Go to "What is the Evidence for Evolution"
Click on “Homology and analogy”
Then click on “Similarities and differences: Understanding homology and analogy”
1. In the image, which pair represents an analogy and which a homology? Define homology: traits inherited from a common ancestor cDefine analogy: similarity not due to common ancestor
2. What is a tetrapod? animals with four legs
3. What are the six bones found in all tetrapod legs? radius, humerus, ulna, carpals, metacarpals, phalanges
4. Identify these limbs (to what animal do they belong)? human, bird, whale, lizard
5. What did the common ancestor of all modern tetrapods look like? like a lizard
6. Side Trip: "not just anatomy." - How are a bird and a crocodile homologous? both take care of their young
7. Similar structures that evolved independently are called _analogies____.
8. a) What is the difference between a marsupial and a placental? marsupials develop young within a pouch
b) What is Smilodon? saber toothed cat
c) What is Thylacosmilus? related to marsupials, has saber like teeth
9. Describe how two unrelated flowers could evolve to have a similar appearance? they both evolved to have a similar function, like attracting birds
10. Are similarities between sharks and dophins homologous or analogous? analogous, they evolved for the same purpose (swimming)
11. What is morphology? form and structure of an organism
12. What three criteria are used to determine whether something is a homology or analogy? structure, relationship, development panda, chimp, human, gorilla 13. Fill in the blanks of the primate tree. panda, chimp, human, gorilla
14. Considering all of the evidence, are the "wings" (actually flaps of skin stretched between the legs) of sugar gliders and flying squirrels homologous or analogous structures? Explain why you would conclude