Evolution unit notes
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This document contains unit notes on evolution from Charles Darwin's voyage of the Beagle to Jean-Baptiste Lamarck's theory of evolution. It summarizes Darwin's theory of natural selection, noting that there is variation in traits, differential reproduction depending on environmental pressures, and heredity of advantageous traits. Lamarck's theory proposed that use and disuse of organs during an organism's lifetime could influence evolution, and that nature drove organisms to greater complexity over time. The document also discusses using fossil records and comparative anatomy to infer relatedness between species.
Evolution unit notes
- 1. Evolution Unit Notes Charles Darwin – Voyage of the Beagle commons.wikimedia.org http://www.earth-time.org/trollart.html www.geology.ohio-state.edu Jean-Baptiste-LaMarck en.wikipedia.org jschmied©2013
- 2. Evolution Unit Goals1. I can explain, using evidence, how biological evolution accounts for the diversity of species on Earth today. • Include evidence from Developmental Biology comparisons 2. I can give examples of plant and animal adaptations that increase the success of an organism during an environmental change: • Show evidence that Natural Selection causes Genetic traits to vary over time • Show how organisms have improved Survival & Reproduction over time • Using math to support my explanations 1. I can infer how closely related two species are based on their anatomical features • Using evidence from the Fossil Record • Using Evidence from Comparative Anatomy jschmied©2013
- 3. Activity 94 – A Meeting of Minds Charles Darwin – Voyage of the Beagle commons.wikimedia.org Jean-Baptiste-LaMarck en.wikipedia.org • I can give examples of plant and animal adaptations that increase the success of an organism during an environmental change. In this activity you should be able to a. Properly define 4 key evolutionary concepts b. Explain why tall (or short people) often have tall (or short) offspring. Also other differences like blue eyes, blond hair, PTC tasting Etc….. c. Describe the similarities and differences between Charles Darwin and Jean-Baptiste-LaMarck’s theories of Evolution. d. Explain why scientists find Darwin’s theory more convincin e. Describe unique adaptations of at least two species on Earth and explain how these adaptations help the species survive in its environment jschmied©2013
- 4. Jean-Baptiste-LaMarck’s Theory Jean-Baptiste-LaMarck en.wikipedia.org 1. Evolutionary Change comes through use and disuse - Lamarck was struck by the similarities of many of the animals he studied, and was impressed by the plentiful fossil record. • He argued that life was not fixed. So if the environment changed, the organisms had to change their behavior to survive. Thus if an organism used an organ more than they had before, it would increase in its lifetime. • Example: If a giraffe stretched its neck for leaves, for example, a "nervous fluid" would flow into its neck and make it longer. Also Its offspring would inherit the longer neck, and continued stretching would make it longer still over several generations. Meanwhile organs that organisms stopped using would shrink.2. Organisms are driven to greater complexity - Lamarck stated As organisms adapted to their surroundings, nature constantly drove them from simple forms to increasingly complex ones. Lamarck believed that life had begun through spontaneous generation. But he also claimed that new primitive life forms sprang up throughout the history of life. For example: today's microbes are simply "the new kids on the block." Lamarck believed that the long necks of giraffes evolved as generations of giraffes reached for ever higher leaves jschmied©2013
- 5. There is variation in traits. For example, some beetles are green and some are brown. There is differential reproduction. Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do. There is heredity. The surviving brown beetles have brown baby beetles because this trait has a genetic basis. End result: The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown. http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_25 Darwin’s Theory of Natural selection Natural selection is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift. Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. To find out how it works, imagine a population of beetles: jschmied©2013
- 6. http://www.earth-time.org/trollart.html Fossils can be dated relative to one another by noting their positions in layers of rocks, known as strata. Thus fossils found in lower strata (layers) were generally deposited earlier and are older than those on upper layers. This is called the Law of Superposition Rock Layers and Fossil Dating
- 7. Fossil Types for our Core Samples Ammonit e Trilobite Elrathi kingi Knightia Fern Alethopteris serii
- 8. Fossils can be dated relative to one another by noting their positions in layers of rocks, known as strata. Thus fossils found in lower strata (layers) were generally deposited earlier and are older. This is called the Law of Superposition. Click on the image at the left to see this phenomena. Scientists can date the rocks, this gives us the general age of the fossils. In the example at right, we can deduce that the oldest rocks are those that are cut through by other rocks. The next oldest rocks are those that are “doing the cutting” through the oldest rocks, and the youngest rocks lie on top of these layers and are not cut through at all. By making careful observations, we can detect these interruptions in the vertical pattern and use them to get more information about the relative ages of different layers. Sometimes geologic processes interrupt this straightforward, vertical pattern . For example, a mass of rock may cut across other layers, erosion may interrupt the regular pattern of deposition, or the rock layers may even be bent and turned upside-down. Click on the image on the right to see this,. Rock Layers and Fossil Dating Learn More At: http://evolution.berkeley.edu/evosite/evo101/IIE1bStratigraphy.shtml
- 9. Stratigraphy using fossils http://216.166.82.105/FaunalSuccessionInfojschmied©2013
- 10. Darwin also used Evidence from Embryology Comparisons www.geology.ohio-state.edu Embryology data shows that organisms look the same at their earlier stages. This idea could support evolution. Evolution is the idea that many organisms have common ancestors, so it was reasoned that is why they have similar traits. jschmied©2013
- 11. Mutations: jschmied©2013 Beneficial Mutations Genetic variant in cows produces more milk. Sickle cell anemia in red blood cells wards off malaria. Harmful Mutations Heart Disease Mutation produces high amounts of heart diseas Neurological Disorder in Golden Retrievers caused by mutation in mitochondrial DNA
- 14. The evolution of whales! http://evolution.berkeley.edu /evolibrary/article/evograms _03: jschmied©2013 The evolution of whales The first thing to notice on this evogram is that hippos are the closest living relatives of whales, but they are not the ancestors of whales. In fact, none of the individual animals on the evogram is the direct ancestor of any other, as far as we know. That's why each of them gets its own branch on the family tree.
- 15. Cool Resource on Evolution! http://evolution.berkeley.edu/evolibrary/article/evo_01: jschmied©2013