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Explore the reasons why hybrids do not result in the formation of new species and the requirements for populations to become new species. Understand the role of evolution in shaping phenotype and the mechanisms that can lead to extinction or common ancestry.
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1. Why don’t hybrids make a new species? • They don’t live in the same area. • They don’t eat the same foods. • They don’t have a common ancestor. • They can’t reproduce.
2. To become a new species, a population must first ___. • be geographically isolated • join another population • adapt • increase its population
3. Evolution acts upon phenotype because ___. • genes are passed down • traits determines survival & reproduction • genes determine who reproduces • traits don’t get passed down
4. Which evolutionary mechanisms will MOST likely lead to extinction? • analogous structures • gene flow • genetic drift • natural selection
5. Which evolutionary mechanisms will LEAST likely lead to extinction? • analogous structures • gene flow • genetic drift • natural selection
6. Which of these is NOT evidence to show common ancestry? • analogous structures • similar DNA sequences • similar embryo development • homologous structures
7. The fossil record tells us periods of ___ and ___. • gene flow; natural selection • hybridization; speciation • gene flow; genetic drift • extinction; speciation
8. What evidence do we have to show that organisms evolved over time? • Half lives • Fossils • Gene pools • Adaptations
9. You want to find out the exact age of a fossil. Which of these would you use? • Absolute dating • Carbon dating • Radiometric dating • All of these
10. When a giant meteor hit the earth about 65.5 mya, land reptiles died because they starved but marine reptiles survived because they ate food underwater. • Gene flow • Genetic drift • Natural selection • none of these