Which statement is TRUE? A) Mutations occur randomly. B) Natural selection is a random process. C) Evolution is a random process. D) All of the above are true. Tiktaalik appears to: A) be a descendant of the one branch of ancestral horses that survived until today. B) be an extinct species of fish that was also able to fly due to flaps of skin between its fins. C) be a “living fossil” since it resembles many of the earliest fish, yet populations thrive today. D) be an extinct species of giant fish that was subject to strong selection for smaller body size. E) represent a transitional species, somewhere between fish and land animals What is the primary source for new, unique genes in a population? A) mutation B) natural selection C) artificial selection D) crossing over How do scientists “know” the atmospheric levels of carbon dioxide that existed on Earth hundreds or thousands of years ago? A) They deduce it from the carbon dioxide content of fossil fuels. B) They measure it from bubbles of gas trapped in Antarctic ice. C) They estimate it from the relative numbers of carbon-based life forms that existed over time. D) They measure it from erupting volcanoes, bubbling hot springs, and seeping hydrothermal vents. Which of the following is supporting evidence that whales evolved from 4-legged wolf-like mammals that lived on land? A) Whales swim by moving their spines up and down, the same way that other land mammals move. B) Vestigial leg and pelvis bones are present in some whale species C) Whales have skull structures similar to wolves D) All of the above.