Study Guide for lectures 1/18, 1/23/2012 Human Evolution, Dr. Chiu EVOLUTION: CONSTRUCTING A FUNDAMENTAL SCIENTIFIC THEORY Reading: Chapter 2, pp. 21-31 Reading: Chapter 2, pp. 21-31 Web links: Example of Natural Selection: http://news.discovery.com/videos/news-lizards-show-evolution-in-action.html Variation: http://learn.genetics.utah.edu/content/variation/sources/ 1. Evolution: Constructing a fundamental scientific theory a. Charles Darwin was a naturalist. On his journeys, he collected specimens of fossils and many living things. He made two major observations. 1. First, he noted that there are significant physical differences, or variation, between and among members of species, e.g. the finches living on one of the Galapagos Islands look different from finches living on another of the islands. 2. Second, he noted that even on the same island, there are significant physical differences that vary according to habitat (e.g. birds living near the coast are different than birds living in the center of the island). b. Remember the steps of the scientific method. After making these observations, Darwin generated two major questions: 1. Why were the birds different? 2. How did the different species of birds arise? c. Darwin recognized that an adaptation (a physical characteristic that enhances an organism’s ability to survive and reproduce) is a major feature of evolution. d. Eventually he formulated the theory of Natural Selection or his theory of decent with modification. We will discuss an example in class that allows us to see ‘evolution in action’.Study Guide for lectures 1/18, 1/23/2012 Human Evolution, Dr. Chiu e. What were the five scientific disciplines that Darwin drew on to form his theory? Read pages 24-30 of your text. 1. How old is the earth? Did people always think it was this old? 2. Who is Hutton? What did he contribute to our understanding of evolution? What is uniformitarianism? Who is Lyell? 3. As we have learned, the fossil record is the best record of evolution that exists. Who was Georges Cuvier and what did he contribute? What is catastrophism? 4. What is taxonomy? Why is this important for evolution? Who are John Ray and Carolus Linnaeus? How would Linnaeus name humans? We are in the genus Homo and the species sapiens. This is referred to as binomial nomenclature. Today, all living things are named according to Linnaeus’ binomial naming system. Refer to Figure 2.9 in your text. 5. Who is Thomas Malthus and what did he contribute to our understanding of evolution? What do ‘struggle for existence’ and ‘competition for resources’ mean? How did Darwin relate this to physical characteristics of finches and differences in reproductive success? 6. Who is Lamarck and what was his contribution to our understanding of evolution? What is Lamarckism, or ‘inheritance of acquired characteristics’? Refer to Figure 2.11. 7. Who is Alfred Wallace? How did he contribute to our understanding of evolution? 2. Natural Selection a. We will watch a short video of an example of natural selection in action <http://news.discovery.com/videos/news-lizards-show- evolution-in-action.html> and discuss this in class. 3. Importance of Variation and Human Variation a. We will watch a short video <http://learn.genetics.utah.edu/content/variation/sources/> b. We will learn about mutation in detail later in the course. c. Brief survey of human variation d. human genome characteristics 1. 3.2 billion bases 2. only monozygotic twins have an identical genome (but yet MZ twins are not truly "identical". Why?) 3. In contrast to what scientists predicted before the human genome was fully sequenced, we have only about 25,000 'genes' in our genomeStudy Guide for lectures 1/18, 1/23/2012 Human Evolution, Dr. Chiu 4. Each 'gene' in our genome has two alleles, one from each parent 5. Single nucleotide polymorphisms or SNPs occur about 1x every 1000 base pairs (bp). In other words, each person has about 3.2 million base differences from the people they are sitting next to in the classroom. 6. Human variation can affect different things incl. response to pharmaceutical drugs, susceptibility to diseases, ability to eat certain foods,