Transcript*of*Slides*History*of*Evolution,*Darwin,*Natural*Selection*Human*Evolution,*Dr.*Chiu****Slide 2: The process of evolution explains diversity, distribution, and origins of organic matter Slide 3: Evolution is basically defined as common descent with modification. Remember the tree thinking exercise: Lineages diverge from a shared common ancestor (a node). Lineages consist of extinct and extant (living) members. Slide 4: Macroevolution is the level of evolution that is reflected in the fossil record and is what we can observe. It occurs over large timescales. Slide 5: There was a change in how people view the world. Today scientists view the world as a dynamic entity. Slide 6: FIGURE 2.4 James Hutton Hutton (here depicted ca. 1790) founded modern geology with his theory of the earth’s formation. Hutton realized that the same natural processes he observed in Scotland had occurred in the past. Slide 7: FIGURE 2.6 Charles Lyell Lyell (here depicted ca. 1845) rediscovered Hutton’s work and the idea of uniformitarianism. Lyell’s research, based on examinations of geologic strata, confirmed Hutton’s estimate of Earth’s very old age. Slide 8: FIGURE 2.5 Geologic Strata The succession of strata from oldest at the bottom to youngest at the top (as here, in Utah’s Bryce Canyon) marks the formation of new land surfaces over time. Slides 9: FIGURE 2.8a Georges CuvierTranscript*of*Slides*History*of*Evolution,*Darwin,*Natural*Selection*Human*Evolution,*Dr.*Chiu**(a) One of Cuvier’s most important contributions to science was the concept of extinction. Here, Cuvier is depicted examining a fish fossil. Slide 10: A giant crater in Mexico indicates that 65 mya an enormous extraterrestrial object crashed on Earth. Did the impact produce a catastrophe at the Cretaceous-Tertiary (K-T) boundary? Slide 11: FIGURE 2.8b Georges Cuvier (b) In his 1796 paper on fossil and living elephants, Cuvier suggested that mammoth remains represented a species different from any living elephant species and, therefore, mammoth remains were from a species that had gone extinct. This idea was revolutionary, because the common perception was that God had created all species, none of which had ever gone extinct. Slide 12: FIGURE 2.9a Carolus Linnaeus (a) Linnaeus, a botanist, zoologist, and physician, is known for his contributions to the system of classification used today by all biological scientists, including physical anthropologists. He is also thought of as one founder of modern ecology. Slide 13: FIGURE 2.9b Carolus Linnaeus (b) Linnaeus’s hierarchical scheme of nomenclature provided unique names for all varieties of plants and animals, including those shown here. Slide 14: FIGURE 2.11a Thomas Malthus (a) Malthus, the founder of demography, theorized that population size was limited by food supply. Slide 15: FIGURE 2.11b Thomas Malthus (b) London’s crowded conditions influenced Malthus’s view that an insufficient food supply causes some people to fall into poverty, while others are able to acquire the resources they need to thrive. Slide 16: FIGURE 2.12a Jean-Baptiste de LamarckTranscript*of*Slides*History*of*Evolution,*Darwin,*Natural*Selection*Human*Evolution,*Dr.*Chiu** a) Lamarck developed an early theory of evolution involving the inheritance of acquired characteristics. Although his mechanism of evolution was wrong, Lamarck’s recognition of the dynamic nature of life in the past made an important contribution to the development of evolutionary theory. Slide 17: FIGURE 2.12 Jean-Baptiste de Lamarck b) According to the classic (though incorrect) example of Lamarckism, giraffes stretched to reach food at the tops of trees, their necks grew as a result, and they passed on these long necks to their offspring. Slide 18: FIGURE 2.14 Alfred Russel Wallace Although Darwin often gets sole credit for the development of the theory of evolution through natural selection, Wallace (here depicted ca. 1860) contributed substantially to evolutionary theory. Wallace was the leading authority on the geographic distribution of animals, for example, and was the first to recognize the concept of warning coloration in animals. In addition, he raised the issue of human impact on the environment a full century before it became a concern for the general public. Slides 19-22: Charles Darwin and journey of the HMS Beagle. Slides 23-26 Darwin's finches (b–f) These islands are well-known for their many endemic, or native, species, such as the 13 species of Galápagos finches, also known as Darwin finches, that are found only at this location. Slide 27: FIGURE 2.3 Darwin Finches Darwin studied the physical variation in finches living on different islands of the Galápagos. Among other attributes, he studied beak shape, which varied from island to island. Eventually, Darwin related each beak shape to diet, especially to the texture of food and how the food was acquired. Finches with larger beaks typically consumed harder foods, such as seeds and nuts, while finches with smaller beaks ate softer foods, such as berries. Darwin concluded that each finch species had adapted to the particular environment and food resources of its island. Slides 28-30: Natural selection textTranscript*of*Slides*History*of*Evolution,*Darwin,*Natural*Selection*Human*Evolution,*Dr.*Chiu**Slide 31: Rosemary and Peter Grant have observed Darwin's finches for decades. This slide shows natural selection in action. Following a drought, which produces harder seeds, beak depth increased. This shows that beak depth is a genetically transmitted trait that responds in the predicted direction to natural selection. Slide 32: Natural selection acts on the phenotype, which is an interplay between genetics and the environment. Remember that environments shift over time; traits that are advantageous in one environment may not be in another. There is always variation in populations. Slide 33-35: Different types of selection. The example of beak depth increase is an example of directional selection. Slide 36: We watched a short film clip about fence lizards and fire-ants. This slide attempts to illustrate that environments are constantly changing. In the past (and present for some fence lizard populations, birds are the main predator. The behavioral response (determined by genetics to some extent) is to stay very still and to have camouflage