Paleontologists did not just stumble across Tiktaalik. Instead, they formed a hypothesis about where they would find a transitional form between fish and tetrapods. What might have been the logical first step in deciding where to look for a transitional form between fish and tetrapods?

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

Compare the two theories regarding the evolution of dinosaurs and then consider the cladogram above. although the two theories differ on the evolutionary path of dinosaurs, they agree that

According to the article, what valid claim came from the national research council? there is no association between fluoride exposure and increased cancer risk in humans. there is a possible link between fluoride exposure and increased cancer risk in humans. there is a definite link between fluoride exposure and increased cancer risk in humans.