Darwin’s Theory of Evolution The Puzzle of Life’s Diversity Chapter 15-1

WRITE A DEFINITION: EVOLUTION: change over time; the process by which modern organisms have descended from ancient organisms THEORY: a well-supported testable explanation of phenomena that have occurred in the natural world FOSSIL: the preserved remains of ancient organisms

The total variety of all the organisms in the biosphere REMEMBER ! The total variety of all the organisms in the biosphere = ________________ Where did all these different organisms come from? How are they related? BIODIVERSITY

What scientific explanation can account for the diversity of life? ANSWER: A collection of ______________, __________, and ___________ known as ________________________ Scientific facts observations hypotheses EVOLUTIONARY THEORY

Charles Darwin H.M.S. Beagle 5 year The person who contributed the most to our understanding of evolution was ______________________ In 1831, at age 22, he joined the crew of the _______________ as a naturalist for a ________ voyage around the world. Charles Darwin H.M.S. Beagle 5 year

revolutionary hypothesis life changes During his travels, Darwin wrote thousands of pages in his journals, drew pictures of the things he saw, and collected a vast amount of ______________ that led him to propose a _______________________ about the way _____________. evidence revolutionary hypothesis life changes

DARWIN WONDERED? Why do Argentina and Australia have ________ ______ even though they have ________ grassland ____________? Why are there no ______ in Australia and no ________ in England? Why have so many species disappeared? How are these ______ species related to living species? different animals similar ecosystems rabbits kangaroos extinct

Who Was Charles Darwin? Galápagos Islands finches tortoises While on his voyage around the world aboard the ____________, Charles Darwin spent about one month observing life on the ________________. There, he encountered some unique animals, such as ______ and ________. H.M.S. Beagle Galápagos Islands finches tortoises

The Galάpagos Islands are close together but have very different _______. Some were hot and dry, with little vegetation. Others had more rainfall and were rich in vegetation Each island had its own _____ _________ of plant and animal species. climates unique assortment

Giant Tortoises of the Galápagos Islands Section 15-1 and on Pinta Island, tortoise necks were somewhere in between Pinta Tower Pinta Island Intermediate shell Marchena James Fernandina Santa Cruz Isabela Santa Fe Hood Island Saddle-backed shell Floreana Hood On the desert-like Hood Island, tortoises had long necks… Isabela Island Dome-shaped shell …while on the lush rainforest of Isabela Island, tortoises had short necks…

same species different isolated After his voyage, Darwin spent a great deal of time thinking about his findings. He began to wonder if animals living on different islands had once been members of the ____________ that had developed _________ characteristics after becoming _______ from one another in different habitats. same species different isolated

Darwin’s Theory of Evolution Ideas that Shaped Darwin’s Thinking Chapter 15-2

Ideas that shaped Darwin’s thinking: proposes that the EARTH was _______ by _________________ occurring over __________ periods of time, and is _______________ old. James Hutton shaped geological forces very long millions of years

Ideas that shaped Darwin’s thinking: explains that the geological processes still ___________ have shaped Earth’s features over ________________ Charles Lyell occurring now long periods of time

Ideas that shaped Darwin’s thinking: Theory of Pangaea …and continental drift

Living things must compete for food, shelter, space, mates REMEMBER ! Chapter 3 competition Living things must compete for food, shelter, space, mates

insufficient space & food Ideas that shaped Darwin’s thinking: _____________________ He observed that babies were being born faster than people were dying. He reasoned that if the human population continued to grow, sooner or later there would be _______________________ Thomas Malthus (1798) insufficient space & food

Jean-Baptiste Lamarck (1809) Ideas that shaped Darwin’s thinking: ___________________________ was one of first scientists to recognize living things _______________ and that all species were ________ from other species. Lamarck published his hypothesis of ________________________ the year Darwin was born. Jean-Baptiste Lamarck (1809) changed over time descended Inheritance of Acquired traits

The male fiddler crab uses its front claw to _________mates and fight off _____________. attract predators repeated Through _________ use, the front claw becomes ________. larger The fiddler passes on this __________ characteristic to its offspring acquired

What’s wrong with Lamarck’s hypothesis? Lamarck didn’t know about genes and how traits are _______. If you lifted weights your whole young adult life, and then you had children, would your kids be more muscular? inherited ACQUIRED PASSED ON NO! ________ traits can ____ be __________ to their offspring. NOT

What’s right with Lamarck’s hypothesis? Lamarck was first to develop a scientific hypothesis about _______ and recognize that organisms are ________________________ evolution adapted to their environments

Match the letter of the idea with the man or men who proposed it: Hutton Lyell Malthus Lamarck Match the letter of the idea with the man or men who proposed it: The earth is really old, and slowly changes Living things pass changes on to their offspring, leading to species changes Sooner or later growing populations run out of resources Living things change slowly over time because of competition for resources, and pass those changes on to their offspring

c. Malthus Hutton a. Lamarck Lyell b. d. The earth is really old, and slowly changes Living things pass changes on to their offspring, leading to species changes Sooner or later growing populations run out of resources Living things change slowly over time because of competition for resources, and pass those changes on to their offspring

Concept Map Section 15-3 Evidence of Evolution includes The fossil record Geographic distribution of living species Homologous body structures Similarities in early development which is composed of which indicates which implies which implies Physical remains of organisms Common ancestral species Similar genes