Name:__________________ Pd._____ Date:_________________ Evidence for Evolution – Gallery Walk Theodosius Dobzhansk, a geneticist whose work influence 20th century research on evolutionary theory, said, “Nothing in biology makes sense, except in light of evolution.” This quote emphasizes the role of evolution as the most important unifying principal in biology. Living things might, at first, seem very diverse, but closer inspection reveals a surprising unity. This unity, or common ancestry, can be explained by evolutionary theory. With such an important theory at stake, it is essential to understand the evidence upon which it is based. Your Task: In this Gallery Walk you will investigate a variety of types of evidence for evolution. You will be responsible for learning about fossil evidence, structural evidence, and genetic evidence for evolution. You will rotate through each station in groups, examining the evidence and answering the questions below. You are free to share thinking but do not copy each other’s answers. Evidence of copying will result in no credit. Station 1: Fossil Evidence - Examine the images of fossils and read the accompanying explanations. 1. What is a fossil?_________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 2. How do paleontologists know how old certain fossils are?________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 3. What similarities and differences do the different hominid fossils share?___________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 4. How is “Lucy” similar to both chimpanzees and humans? Name specific traits._______________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 5. How does this evidence support the theory of evolution?________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 6. What are you still wondering about fossil evidence?____________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Station 2: Homologous Structures – Compare and contrast the images of embryos and forelimbs. 1. What is a homologous structure?___________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 2. How the wing of a bat similar to the flipper of a whale and the arm of a human?_____________ ______________________________________________________________________________ ______________________________________________________________________________ 3. What similarities and differences did you notice across all of the embryo examples? Name specific features_________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 4. What did the common ancestor of pitcher plants, venus fly traps, poinsettias, and cacti probably look like?_______________________________________________________________________ ______________________________________________________________________________ 5. How does this evidence support the theory of evolution?________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 6. What are you still wondering about homologous structures?_____________________________ ______________________________________________________________________________ ______________________________________________________________________________ Station 3: DNA Evidence – Compare the sample DNA strands. Try to predict which ones are more or less related based on their differences. 1. Identify relatedness between the 5 species’ DNA samples. Write down your prediction before checking with Ms. Dignan for the answer. ____________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 2. Was your prediction right or wrong?_________________________________________________ 3. Two of the species had identical DNA readings. How could this be?________________________ ______________________________________________________________________________ ______________________________________________________________________________ 4. What can DNA tell us about a given individual?________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 5. How does this evidence support the theory of evolution?________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 6. What are you still wondering about DNA evidence?____________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Station 4: Vestigial Traits – Look through the examples of vestigial traits in humans and whales. Think about how and why they exist. 1. What is a vestigial trait?___________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 2. Why do whales have leg bones?____________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 3. Why are humans still born with appendixes?__________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 4. If organisms don’t have any use for vestigial traits, why don’t they just go away?_____________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 5. How does this evidence support the theory of evolution?________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 6. What are you still wondering about vestigial traits?_____________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________