Introduction To Evolution PDF

CHARLES DARWIN Theory of Evolution A scientific theory is a well- supported testable explanation of phenomena that have occurred in the natural world. How do you think Darwin came up...

CHARLES DARWIN Theory of Evolution A scientific theory is a well- supported testable explanation of phenomena that have occurred in the natural world. How do you think Darwin came up with his theory? CHARLES DARWIN CHARLES DARWIN CHARLES DARWIN He published the book “The Origin of species in 1859” Patterns of Diversity Darwin visited Argentina and Australia which had similar grassland ecosystems. those grasslands were inhabited by very different animals. neither Argentina nor Australia was home to the sorts of animals that lived in European grasslands. Living organisms and fossils Darwin collected the preserved remains of ancient organisms, called fossils. Some of those fossils resembled organisms that were still alive today. The Galapagos Island Darwin was fascinated in particular by the land tortoises and marine iguanas in the Galápagos. Giant tortoises varied in predictable ways from one island to another. The shape of a tortoise's shell could be used to identify which island a particular tortoise inhabited. Animals found in the Galapagos Island Land Tortoises Darwin Finches Blue-Footed Booby Marine Iguanas Journey Home Darwin Observed that characteristics of many plants and animals vary greatly among the islands Hypothesis: Separate species may have arose from an original ancestor Idea that shaped Darwin’s Thinking James Hutton 1795 Theory of Geological change Forces change earth’s surface shape Changes are slow Earth is much older than thousands of years Idea that shaped Darwin’s Thinking Charles Lyell Book: Principles of Geography Geographical features can be built up or torn down Darwin thought if earth changed over time, what about life? Idea that shaped Darwin’s Thinking Thomas Malthus 19th century English economist Increase in population may mean that? And what are the consequences? Idea that shaped Darwin’s Thinking Jean Lamarck Lamarck’s Theory of Evolution Use and Disuse Inheritance of Acquired Traits Publication of Origin of Species Russel Wallace wrote an essay summarizing evolutionary change from his field work in Malaysia Gave Darwin the drive to publish his findings Darwin’s Observations Observed differences among island species Variation Adaptation Darwin’s Observations 9 distinct species of finches in the Galapagos islands, all very similar for each other except for their bills Darwin’s Observations Darwin’s Observations Darwin’s Theory Inherited variation exists within the genes of ever population or species Darwin’s Theory In a particular environment, some individuals of a population or species are better suited to survive Darwin’s Theory Overtime, the traits that make certain individuals of a population able to survive and reproduce tend to spread in that population Darwin’s Theory There is overwhelming evidence from fossils and many other sources that living species evolved from organisms that are extinct KEY CONCEPTS DERIVED FROM DARWIN’S THEORY Natural Selection KEY CONCEPTS DERIVED FROM DARWIN’S THEORY Artificial Selection KEY CONCEPTS DERIVED FROM DARWIN’S THEORY Artificial Selection KEY CONCEPTS DERIVED FROM DARWIN’S THEORY Artificial Selection Is there any harmful effect of artificial selection? KEY CONCEPTS DERIVED FROM DARWIN’S THEORY Population All the individuals of species that live in a specific geographical area and that can interbreed KEY CONCEPTS DERIVED FROM DARWIN’S THEORY Natural Section explains how evolution can occur Variation Overproduction Adaptation Descent with modification Other Factors Selective pressure Factors in the environment select FOR or AGAINST a genetic trait Other Factors Sexual selection Intra-sexual- males compete against each other to win a mate Inter-sexual- females choose a mate based on specific male traits