1. What kinds of questions can the fossil record help us to answer? The fossil record can help us answer questions about what land looked like in the past and how organisms moved through it. 2. Describe the difference between a body fossil and a trace fossil. Body fossils are the fossilized remains of body parts, whereas trace fossils are any fossilized evidence of the organism excluding the actual organism. Examples of body fossils include leaves, teeth, skin or bones, while examples of trace fossils include burrows, footprints, nests or coprolites. 3. Why are organisms that are buried rapidly more likely to fossilize than those that are buried slowly or not at all? When organisms are buried rapidly, they are protected from various biotic factors such as scavengers and decomposers, as well as from abiotic factors such as sun and wind. This process allows fossilization to begin. 4. Describe two ways an organism can become a fossil without being buried in sediment. Fossilization can occur when organisms undergo freezing, drying or encasement, such as in ice, tar or resin. 5. How does the environment affect the formation of fossils? There is a higher chance that fossils will form in that area if an environment is conducive to the rapid and complete burial of an organism. This is shown at the bottom of the oceans or lakes, as there are many fossils found in these areas. However, if an environment has many abiotic and biotic factors such as those found in rain forests or rocky shorelines, fossilization is much less likely to occur. 6. Describe three factors that could prevent an organism from long ago from ever turning up in a fossil collection today. Many factors could prevent an organism from ever turning up in a fossil collection today. One of the reasons an organism may never turn up in a fossil collection today is that not all organisms live and die in areas conducive to fossilization. The organisms that do become fossils may be subjected to destructive geological forces such as melting and erosion, and even then, many fossils are buried deep within the Earth and may never be found. 7. How are geologic maps useful to paleontologists? Geologic maps are useful to paleontologists as they show what type and age of rock are found at the Earth’s surface. Paleontologists can use this information to target specific rocks that may contain the information they need to answer their questions. 8. In your own words, explain why the fossil record is not complete. The fossil record is incomplete for a myriad of reasons. Only some organisms live and die in environments conducive to fossilization, and even as fossils are threatened by geologic forces. Additionally, many organisms may never become fossils as organisms with hard body parts have a significantly higher chance of becoming fossils than organisms with soft-body parts. As a result of this, the fossil record contains only a few remains of organisms such as jellyfish, earthworms and flowers. Resources: Collins, J. J., & Lindstrom, K. (n.d.). Retrieved from https://ucmp.berkeley.edu/education/explorations/tours/fossil/9to12/intro.html 1. Of the 30 million species of living things estimated to exist today, how many of them are not animals? It is estimated that 28.5 million species of living things are not animals. 2. Find the timeline. How many millions of years did dinosaurs exist on Earth before they became extinct? Dinosaurs existed for approximately 160 million years before they became extinct. 3. Name at least 5 things other than bones that can be preserved as fossils. Many things, such as leaves, shells, and pollen, can be preserved as fossils. Additionally, indications of an organism's activities such as footprints, organic compounds they produced, and burrows can be preserved as fossils. 4. Explain what divergence is. Divergence occurs when one ancestral species gives rise to many different descendant species. 5. In your own words, describe what cladograms represent. A cladogram represents evolutionary relationships and patterns of divergence within groups of organisms. 6. What types of evidence are used to determine evolutionary relationships? Evolutionary relationships can be determined by comparing similarities in embryology, as well as similarities in DNA and anatomy, and collecting information from the fossil record. 7. In your own words, explain how Geospiza Fortis is a good example of natural selection. The Geospiza finch lived on the Galapagos island and preferred smaller, more delicate seeds until 1977 when a drought killed off these plants. This drought forced the finches to eat larger, harder seeds in order to survive. As a result of this change to the finches' food supply, only the birds with larger bodies and beaks were able to survive and reproduce, and their population dropped significantly. The year after the drought, the G. fortis population consisted entirely of individuals with large bills and large bodies. Natural selection occurred in this situation as the drought led to a change in the food supply and a subsequent change in the finches' population. 8. Describe two other mechanisms for evolution in addition to natural selection. In addition to natural selection, genetic mutations in which a permanent change to an organism's DNA occurs, and geographic isolation are two evolutionary mechanisms for evolution. 9. Give an example of an animal that has gone extinct because of human influence and explain what happened. The stellar's sea cow, a manatee-like creature, is an example of an animal that has gone extinct as a direct result of human activity. The sea cow, which was unknown to science until 1741, was described by German naturalist Georg W. Steller, who accompanied Vitus Bering on his voyage of discovery in the North Pacific. Within 27 years, the animal had been hunted to extinction for its meat and hide. Sea cows were wastefully overexploited, based on the belief held by most 18th-century naturalists that the sea was inexhaustible, and extinction impossible. This was not the case as the last sea cow seen in the wild was spotted by fur hunters in 1768. References: n.d.). Retrieved from https://ucmp.berkeley.edu/education/explorations/tours/intro/index.html Mikanowski, J. (2017, April 19). The Giant Sea Mammal That Went Extinct in Less Than Three Decades. Retrieved from https://www.theatlantic.com/science/archive/2017/04/pleistoseacow/522831/ O'Shea, T. (2020, May 8). Sea cow. Retrieved from https://www.britannica.com/animal/sea-cow 1) How is relative age different from the actual date of an event? Relative age is different from the actual date of an event because relative age allows scientists to determine the order in which events occurred, not the actual date of an event. Knowing the actual date of an event enables scientists to determine the exact age of an object or how long ago something took place. 2) What can radiometric dating tell us about the age of rocks that the Law of Superposition Cannot? The Law of Superposition can only be used to determine the relative age of rocks, whereas radiometric dating can be used to determine how old the rocks are. 3) How can you find the age of a layer of rock that is surrounded by layers of volcanic ash? First, radiometric dating can be used to determine the age for the surrounding layers of volcanic ash. After this, it can be said that the age of the intervening layer is intermediate between those dates. 4) What do the periods in the geologic time scale represent? Each period in the geologic time scale represents a unique change in the plants and animals at that time. 5) What do the terms Paleozoic, Mesozoic and Cenozoic mean? The term Paleozoic means ancient life, Mesozoic means middle life, and the term Cenozoic refers to the time of recent life. Resources: (n.d.). Retrieved from https://ucmp.berkeley.edu/education/explorations/tours/geotime/index.html |
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