CHAPTER THREE EVOLUTION HISTORY AND EVIDENCE

Pre~Darwinian Theories of Change The idea of evolution did not originate with Charles Darwin.

Darwin’s Early Years and His Journey At the age of 16 he entered medical school in Edinburgh, Scotland During his stay at Cambridge, Darwin developed a keen interest in collecting beetles and made valuables contribution to beetle taxonomy

Early Development of Darwin’s Ideas of Evolution Darwin’s theory of evolution by natural selection was long, painstaking process. Darwin had to become convinced that change occurs overt time During his voyage suggested that change occur, he realized the 6000 years could not account for the diversity of modern species if they arose through gradual change

Geology Lyell developed the ideas of another geologist, James Hutton, into the theory of uniformitarianism His theory was based on the idea that the forces of wind, rain, rivers, volcanoes, and geological uplift shape the earth today, just as they have in the past.

Fossil Evidence Once the HMS Beagle reached South America, Darwin spent time digging in the dry riverbeds of the pampas (grassy plains) of Argentina He found the fossil remains of an extinct hippopotamus like animal, now called Toxodon, and fossil of a horselike animal, Thoantherium Natural Selection

Charles Darwin had no knowledge of modern genetic concepts and therefore, had no knowledge of the genetics principles that are the the basic of evolutionary theory as its exists today

Adaptation Occurs when a change in a phenotype increases an animals chance of successful reproduction. Adaptation sometimes used of the term is probably less confusing ran when it is used to describe the result of the process of change

Alfred Russell Wallace He was an explorer of the Amazon valley and the led a zoological expedition to the Malay archipelago Wallace like Darwin was impress with the evolution change and had the writing of Thomas Malthus o human populations

Microevolution, Macroevolution, and Evidence of Macroevoluntionary Change A change in the frequency of alles in population over time is called microevolution The processes that result in microevolution are discussed..

Biogeography Is the study of the geographic distribution of plants and animals. They studied show that life forms in different parts of the world have distinctive evoluntionary histories

Paleontology Which is the study of the fossil record provides some of the most direct evidence for evolution

Analogy and Homology The evolution of superficially similar structures in unrelated organism is called convergent evolution Structure and processes in two kind of organisms that are derived from common ancestry are said to be homologous

Development Patterns Evidence of evolution also comes from observing the development pattern of organism

Interpreting the Evidence: Phylogeny and Common Descent Phylogeny refers to the evolutionary relationship among species