22. Evolution and the Origins of Life

Which of the following statements describes a vestigial structure?

Dinosaurs went extinct approximately 65 million years ago (mya). Fossils of the organism Archaeopteryx have been found in strata dating to approximately 150 mya. These fossils show a dinosaur-like skeleton with a bony tail, teeth, and claws, as well as clear impressions of feathers similar to those found in flying birds. It is thought that Archaeopteryx belongs to a group of dinosaurs from which birds evolved. Which statement below is consistent with the evidence presented above?

A similar arrangement of internal organs is observed in birds, rodents, and frogs. This is likely an example of:

Different alleles of the MC1R gene have been associated with hair/coat color variation in many different mammals, including mice, jaguars, cows, and humans. In humans, specific mutations of the MC1R gene are associated with red hair. Using the concept of homology, explain why the same gene would affect similar traits in multiple organisms.

The potato (Solanum tuberosum) and the sweet potato (Ipomoea batatas) are both plants that form starchy tubers. A tuber is an underground part of plant used for nutrient storage and is the part of the potato and sweet potato that we eat. Most other plants of both the genus Solanum, which includes the tomato and the eggplant, and the genus Ipomoea, which includes the morning glory, do not form tubers. As described do you think the tubers found in potatoes and sweet potatoes are more likely an example of analogy or homology and why?

Sedimentary rock creates distinct layers that paleontologists can use to help interpret their findings. Use the image below to determine which of the following statements is true about fossils and sedimentary rock.