found in rock that is about 65 mya 200 mya because the animal lived that 4- Trilobites

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1 Fossil Evidence of Extinction and Environmental Change Sequencing Using the chart on page one, list the following living organisms in the order in which they first appeared on Earth. 1- Single-celled organisms / bacteria Faunal Succession means that fossils can be used to identify the relative 2- Animal Cells age of the layers of a rock formation. For example, dinosaur fossils are 3- Jellyfish found in rock that is about 65 mya 200 mya because the animal lived that 4- Trilobites long ago. The fossils of modern humans are found in rock that is about 5- Insects 40,000 years old, but not in rock that is million years old. And 6- Giant Ferns / Palm Trees dinosaurs are not found in rock that is 40,000 years old. This means that 7- Dinosaurs human beings did not live at the same time as the dinosaurs. 8- Flowering Plants 9- Humans Analyze When did the most recent mass extinction happen? About how long ago did it happen? The most recent mass extinction occurred about 65 million years ago at the end of the Cretaceous period. This was the event that killed all of the dinosaurs, as well as many other species. This graph measures time in units of millions of years. All of human history fits into a mere sliver of time. We actually show up late to the New Year s Eve party on December 31 st, 11:55 p.m. to be exact. Relate What is the relationship between extinction and environmental change? Species become extinct if they cannot find resources to survive in a changing environment. Define What is the definition of gradual change and sudden change. Give 3 examples of each. Gradual Change A natural process where geologic features are modified over long periods of time. Examples include plate tectonics, erosion (Grand Canyon), formation of deserts, formation of beaches Sudden Change When environments change quickly. Examples include volcanic eruption, meteorite impacts, mass flooding, earthquakes. State What patterns did scientists find in the fossil record? Fossils can consist of the hard parts or soft parts of organisms. Fossils can be an impression of an organism or consist of original tissues. Scientists determine the sequence or relative age of these fossils using faunel succession. Scientists use fossils as evidence that species have changed over time. Analyze How are fossils evidence of biologic change over time? Biologic Evolution is the change over time in populations of related organisms. The Fossil Record shows how species change over time. Extinctions are evidenced by the disappearance of fossils of a species from one rock layer to the next. Biologic evolution is evidenced by the gradual progression of organisms changed body structures (Natural Selection/Variation) throughout the fossil record, from one layer to the next. In both cases, one must look at multiple rock layers at the same time to make comparisons. Evaluate In what ways did the horse change over time? The legs are getting thicker and the three-toed feet are evolving into one large toe a hoof. These changes occurred because the animals got larger and heavier, so sturdier legs and feet were necessary to support them. This is just one example that you could use. Theory of Variations Define What are variations? A variation is a slight difference in an inherited trait of individual members of a species. The variations among the shells of a species of tree snail occur naturally within the population.

2 Analyze What role do variations have in natural selection? Natural Selection is the process by which populations or organisms with variations that help them survive in their environments, live longer, compete better, and reproduce more than those that do not have variations. If a variation helps an organism survive in its environment, it increases in the population through natural selection. Visualize Refer to the illustration of the tortoises that have short necks and long necks. What trend do you see over time? These illustrations do not show the same tortoises, but rather tortoises removed by many generations. Between the first and last illustration, the tortoise s neck length increased notably. The principle of natural selection explains the change in the neck length of a tortoise species, as well as other changes in animal structure over time. Tortoises with longer necks are able to reach more food in that environment. Those tortoises will be stronger and more apt to survive and bread. They will pass on their traits such as longer necks to their offspring. Eventually the weaker, shorter-necked turtles will die out, and all turtles will have long necks. Explain Why are there so many different kinds of finches and mockingbirds on the Galapagos Islands? Natural selection is the process by which populations of organisms with variations that help them survive in their environments live longer, compete better, and reproduce more than those that do not have the variations. Natural selection explains how Galápagos tortoises became matched to their food sources, as explained above. It also explains why there were so many different kinds of Galápagos finches and mockingbirds. Birds with beak variations that helped them compete for food lived longer and reproduced more. Explain How do variations lead to adaptations? An adaptation is a characteristic of a species that enables the species to survive in the environment. Beneficial variations spread to entire populations through natural selection and produce adaptations that enable the populations to survive in their environments. Define What is camouflage and how does it benefit an organism? Camouflage is an adaptation that enables a species to blend in with its environment. If an organism is unable to adapt it could become extinct. When an organism is able to adapt it increases it chances for survival. An example of camouflage is when a Seahorse is able to blend in with the coral that it is resting on. Define What is mimicry and how does it benefit an organism? Mimicry is the resemblance of one species to another species. If an organism is unable to adapt it could become extinct. When an organism is able to adapt it increases it chances for survival. An example of mimicry is when a caterpillar looks like a snack, which helps it avoid being eaten. The walking stick s shape looks like its environment. This conceals the insect from predators and helps it live longer. Contrast How do camouflage and mimicry differ? In camouflage, species adapt to their surroundings. In mimicry, species adapt to resemble or look like their surroundings. Synthesize How do you think some fur-bearing species might adapt to a gradual change in climate in which global temperature increased? This is the hardest question for me to answer for you because there is a wide range of answers that would be correct. Possible answers could include: - The species could stay still during the hottest part of the day to help it conserve energy. - The species may shed fur to help it cool down during the hottest part of the day. - The species could develop blood vessels in the ears to expand to enable the blood to cool before re-entering the body. - The species could develop strong legs to help it run fast to escape potential predators and capture available prey.

3 The Environment and Change Over Time Infer What is the function of the bones in bats that are homologous to finger bones in humans? Homologous structures have similar parts that suggest a shared origin, but homologous structures are not identical. For example, the fingerlike bones of a bat are much longer than the bones in other animals. The finger and hand bones of a human are very flexible and include an opposable thumb, which is a thumb that bends in a perpendicular direction to the other fingers which allows the human hand to grasp objects. (Objects, such as, a Coke Zero to bring to your favorite teacher.) Explain How do homologous structures provide evidence for change of organisms over time? Similar bone structures among animals can reveal how animals are related and how they change over time. The more similar a structure is in two living species, the more likely the species share a close common ancestor. Infer Why does a vestigial pelvis show that the ancestors of the modern whale once had legs? The modern toothed whale has tiny pelvic bones inside its body. Pelvic bones are hip bones which attach the leg bones to the body. Whales do not have legs. The pelvic bones would suggest that whales came from ancestors that used legs for walking on land. Explain How are vestigial structures evidence of descent from ancestral species? Vestigial Structures are body parts that have lost their original function through biologic change. A structure with no or reduced function in a living species is evidence that the species evolved from an ancestor that used that structure. Analyze How do pharyngeal pouches provide evidence of relationships among species? Because embryos of different species often resemble each other at different stages of development, such as having pharyngeal pouches. Scientists believe that they share a common ancestor.

4 Fossil Evidence of Extinction and Environmental Change Sequencing Using the chart on page one, list the following living organisms in the order in which they first appeared on Earth. Analyze When did the most recent mass extinction happen? About how long ago did it happen? Relate What is the relationship between extinction and environmental change? Define What is the definition of gradual change and sudden change. Give 3 examples of each. State What patterns did scientists find in the fossil record? Analyze How are fossils evidence of biologic change over time? Evaluate In what ways did the horse change over time? Theory of Variations Define What are variations? Analyze What role do variations have in natural selection? Visualize Refer to the illustration of the tortoises that have short necks and long necks. What trend do you see over time? Explain Why are there so many different kinds of finches and mockingbirds on the Galapagos Islands?

5 Explain How do variations lead to adaptations? Define What is camouflage and how does it benefit an organism? Define What is mimicry and how does it benefit an organism? Contrast How do camouflage and mimicry differ? Synthesize How do you think some fur-bearing species might adapt to a gradual change in climate in which global temperature increased? The Environment and Change Over Time Infer What is the function of the bones in bats that are homologous to finger bones in humans? Explain How do homologous structures provide evidence for change of organisms over time? Infer Why does a vestigial pelvis show that the ancestors of the modern whale once had legs? Explain How are vestigial structures evidence of descent from ancestral species? Analyze How do pharyngeal pouches provide evidence of relationships among species?