Transcript Evolution
Evolution Chapter 15 of Biology Text Chapter 4 of Environmental Science Text Student Performance Standards SB5. Students will evaluate the role of natural selection in the development of the theory of evolution. • a. Trace the history of the theory. • b. Explain the history of life in terms of biodiversity, ancestry, and the rates of evolution. • c. Explain how fossils and biochemical evidence support the theory. Lesson Essential Question How do organisms adapt to their environment? Write down the characteristics you think help the chameleon when it hunts. Charles Darwin (1809-1882) English Naturalist Sailed on the HMS Beagle from 1831 - 1836 His job was to collect biological and geological specimens during the ship’s travels to S. America. • Collected rocks, fossils, plants, and animals Galapagos Islands: • A series of islands off the coast of S. America • Darwin reached the islands in 1835 • Each island had it’s own slightly different variety of plants and animals. • Darwin collected mockingbirds and finches • “Darwin’s Finches” • Darwin began to suspect populations from the mainland changed after reaching the Galapagos. • Hypothesized that new species could appear gradually through small changes in ancestral species. Galapagos Islands – a series of volcanic islands off the coast of Ecuador Natural Selection Darwin proposed that the environment exerts a strong influence over which individuals survive to produce offspring. Darwin used the term natural selection to describe the survival and reproduction of organisms with particular traits. Add These Vocab Words To Your Study Guide What What What What are genes? are traits? does heredity mean? are heritable traits? What is different about these finches? Why? Principles for Natural Selection 1. Differences within a population are visible and vary in each generation. 2. Variations can be inherited. 3. More individuals are born than live to grow up and reproduce. 4. Individuals with some genes are more likely to survive and reproduce than individuals with other genes. Darwin’s Conclusion Based on the 4 principles listed on the previous slide, Darwin concluded that individuals with genetic traits that make them more likely to grow up and reproduce in the existing environment will become more common in the population from one generation to the next. What is Evolution? - Darwin proposed that over many generations, natural selection causes the characteristics of populations to change. A change in characteristics from one generation to the next is evolution. - Evolution works on populations not individuals. - Evolution is CHANGE OVER TIME. Support for Evolution 1. Fossil Record: Glyptodonts Armadillos Ratite Birds The Origin of Species 1859 – Darwin published On the Origin of Species by Means of Natural Selection Main Points: • The diverse forms of life have arisen by descent with modification from ancestral species. • The mechanism of modification has been natural selection working over enormous tracts of time. Darwin used the term evolution only on the last page. Adaptations See Figure 8 on page 105 in ES Book. The deer’s thick fur is an adaptation – an inherited trait that increases an organism’s chance of survival and reproduction in a certain environment. Coevolution Coevolution is the process of two species evolving in response to longterm interactions with each other. Artificial Selection vs. Natural Selection Artificial Selection – Selective breeding (dogs, plants that grow fruit) Darwin inferred that the same process could happen in nature to create new species. Natural Selection – if given enough time, natural selection could modify a population enough to produce a new species. + = Evolution of Resistance Resistance is the ability of one or more organisms to tolerate a particular chemical designed to kill it. See Figure 11, page 107 HIV Antibiotics prescribed to cure bacterial infections PBS Video Clips http://www.pbs.org/wgbh/evolution/educ ators/teachstuds/svideos.html Watch “Isn’t Evolution Just a Theory?” Watch “Who Was Charles Darwin?”