2 - Evolution - history.pdf

 What is evolution? Chapter 22 https://www.pinterest.com/pin/482870391269213434/ Evolution: descent with modification, change in genetic...

 What is evolution? Chapter 22 https://www.pinterest.com/pin/482870391269213434/ Evolution: descent with modification, change in genetic composition of a population over time Evolution as a pattern of evolutionary change revealed by scientific data Evolution as a process that consists of mechanisms that produce the observed pattern of change Who was Charles Darwin? Historical context of Darwin’s life and ideas Who? What? Huh? Georges Cuvier – paleontologist Different fossils in different layers of rock  Who? What? Huh? James Hutton – geologist Earth’s geologic features could be explained by gradual mechanisms Charles Lyell – geologist Same geological processes are happening today at same rate Gradual processes  Who? What? Huh? Thomas Malthus – economist Much of human suffering caused by population increases faster than food supplies & other resources Long before Darwin was born, idea existed that life gradually changed over time  Changes through time Jean-Baptiste Lamark – biologist Compared living species with fossils The environment gives rise to changes in animals Individuals acquire traits: become more complex, develop into new forms HOW?  Use and disuse hypothesis Inheritance of acquired characteristics Later has long- necked babies So again…. Who was Charles Darwin? Charles Darwin Outdoor & nature enthusiast Parents forced him to go to medical school He quit to join the clergy (many scientists were clergy at that time) Graduated & met Captain Robert FitzRoy - captain of the HMS Beagle Paid his own way onto the Beagle to serve as a professional BFF to Captain FitzRoy (because long voyages are boring) & also serve as the ship’s naturalist Ashore Darwin…. Collected plant & animal specimens Described features of organisms that made them suited to their diverse environments Noticed the plants & animals in temperate areas of South America more closely resembled species from SA tropics rather than temperate regions of Europe Witnessed earthquake that caused rocks along coast to rise Found fossils of oceanic species on mountain tops Galapagos Islands http://www.michaelcreasy.com/photos/galapagos.html http://neomcgill.blogspot.com/  Descent with modification: new species arise from an ancestral form by the gradual accumulation of adaptations (modifications) to different environments Natural selection Darwin proposed Natural selection as the mechanism to explain the patterns of evolution He used artificial selection (AKA selective breeding) as evidence Could the environment impose selective pressure? Alfred Russel Wallace  Darwin hurried up and published his book The origin of species 2 main ideas Descent with modification Natural selection