Concept explainers
Geology and Life. In Chapter 4, we discussed the role of plate tectonics and the CO2 cycle in climate regulation on Earth. Suppose neither of these processes had ever operated. Could life still have arisen on Earth as discussed in this chapter? If so, how far could evolution have progressed before the lack of climate regulation would have blocked further major developments? Write a one-page essay summarizing and explaining your answers.
Trending nowThis is a popular solution!
Chapter 6 Solutions
Life in the Universe (4th Edition)
Additional Science Textbook Solutions
Conceptual Physics (12th Edition)
University Physics (14th Edition)
College Physics: A Strategic Approach (3rd Edition)
Applied Physics (11th Edition)
Tutorials in Introductory Physics
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
- If you represent Earths history by a line that is 1 m long, how long a segment would represent the 400 million years since life first moved onto the land? How long a segment would represent the 4-millionyear history of humanoid life?arrow_forwardCO2 and planetary warming: understanding Earth’s complicated atmosphere Mars has an atmospheric pressure of 6 mbar (compared with Earth atmosphere pressure of 1013 mbar), 96% of which is CO2. The average calculated temperature of Mars is -57°C, whereas the actual average temperature is -55°C so that the amount of warming due to CO2 is only 2°C. On the other hand, the average calculated temperature of Earth, with 0.4 mbar of CO2, is -19°C, whereas the actual average temperature is 15°C so that the amount of warming due to CO2 is 34°C, much greater than that on Mars, which has higher CO2 concentration. Explain how this is possible.arrow_forwardWhich of the following seems least reasonable regarding life on Earth? Group of answer choices There is much scientific evidence suggesting that all creatures living on Earth today appear to have evolved from a common ancestor. Louis Pasteur discredited the concept of spontaneous generation by demonstrating that even bacteria and other microorganisms arise from parents resembling themselves. There is ample physical evidence that the earliest life forms on Earth were multicellular creatures, perhaps resembling some of our primitive fish. When the earth formed some 4.6 billion years ago, it was a lifeless, inhospitable place. Before the mid-17th century, most people believed that God had created humankind and other higher organisms and that insects, frogs, and other small creatures could arise spontaneously in mud or decaying matter About billion years into its development, the Earth it was teeming with organisms resembling blue-green algae.arrow_forward
- Detail some of the anthropogenic changes to Earth’s climate and their potential impact on life.arrow_forwardIf we do find life on Mars, what might be some ways to check whether it formed separately from Earth life, or whether exchanges of material between the two planets meant that the two forms of life have a common origin?arrow_forwardWhat is a habitable zone?arrow_forward
- A radio broadcast left Earth in 1911. How far in light years has it traveled? If there is, on average, 1 star system per 400 cubic light years, how many star systems has this broadcast reached? Assume that the fraction of these star systems that have planets is 0.50 and that, in a given planetary system, the average number of planets that have orbited in the habitable zone for 4 billion years is 0.20. How many possible planets with life could have heard this signal?arrow_forwardHow does the habitable zone differ for a star hotter than the sun?arrow_forwardThe principle cause of our intense interest in Mars in the decades before the dawn of the space age was that Answers: A. a few astronomers believed that they saw evidence of an intelligent civilization on Mars. B. Mars has seasons just like the Earth and therefore should be inhabitable by humans. C. Mars has an unusual surface color and global dust storms, creating strange weather patterns. D. Mars has unusual orbital properties making our understanding of its motion around the Sun very difficult.arrow_forward
- Which of the following statements about the "tree of life" is correct? Before Carl Woese, all cellular life forms were classified into five kingdoms: Monera, Fungi, Plants, Animals, and Protists. Using rRNA genes for phylogenetic reconstruction, Carl Woese uncovered a previously unrecognized group that was thought to be bacteria. Afterward, all cellular life forms were classified into three domains: Archaea, Bacteria, and Eucarya. It is found that the relationship among Archaea, Bacteria, and Eucarya changes, depending on which gene was used for phylogenetic reconstruction. All of the abovearrow_forwardLife on Earth exists because of oxygen in Earths atmosphere. True or false? Explain your answer.arrow_forward1. The article states that Tasmanian devils “remov[e] carcasses that might otherwise slowly rot." Which of the following ScienceWorld Name: CHECK FOR UNDERSTANDING: RETURN OF THE DEVINS DIRECTIONS: Use the article "Return of the Devils" (p. 20) to answer the questions hello phrases best defines carcasses? A decaying plants B fallen trees bodies of dead animals O nonnative predators d the dramatic decline of the devil population on the island of Tasmania in the past feN darrow_forward
- Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage LearningStars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
- Horizons: Exploring the Universe (MindTap Course ...PhysicsISBN:9781305960961Author:Michael A. Seeds, Dana BackmanPublisher:Cengage LearningAstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStaxStars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning