Darwin’s Theory of Evolution The Puzzle of Life’s Diversity Chapter 15-1 Image from: Biology by Miller and Levine; Prentice Hall Publishing©2006

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

The theory of _____________ explains where all the diversity on the planet comes from. EVOLUTION

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 Image from: Biology by Miller and Levine; Prentice Hall Publishing© year

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 revolutionary _____________ about the way life changes. hypothesis evidence

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

Who Was Charles Darwin? While on his voyage around the world aboard the H.M.S. Beagle, Charles Darwin spent about one month observing life on the ____________ Islands. He saw some unique animals, such as finches and tortoises found no where else on the planet. Galápagos

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 _____ plant and animal species. Biology by Miller and Levine; Prentice Hall Publishing©2006 climates unique

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

When Darwin returned from his voyage he spent many years studying the specimens he brought back and thinking about all the things he had seen.

Darwin’s Theory of Evolution Ideas that Shaped Darwin’s Thinking Chapter 15-2 Image from: Biology by Miller and Levine; Prentice Hall Publishing©2006

Ideas that shaped Darwin’s thinking: 1785 ______________ proposes that the EARTH was shaped by geological forces occurring over very long periods of time, and is millions of years old. James Hutton

Ideas that shaped Darwin’s thinking: 1833 ___________ explains that the geological processes that shaped the Earth are still happening. Charles Lyell

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

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

Ideas that shaped Darwin’s thinking: 1798_________________ Babies were being born faster than people were dieing. He reasoned that if the human population continued to grow, sooner or later there would NOT be enough _______________for everyone Thomas Malthus space & food

Ideas that shaped Darwin’s thinking: 1809____________________ First scientist to recognize living things change over time and that all species were descended from other species. Lamarck published his hypothesis called the INHERITANCE OF ___________________ the year Darwin was born. Jean Baptiste Lamarck ACQUIRED TRAITS

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

What’s WRONG with Lamarck’s hypothesis? Lamarck didn’t know about _________ and how traits are inherited. If you lifted weights your whole young adult life, and then you had children, would your kids be more muscular? genes

ACQUIRED traits can ____ be __________ to offspring. NOT PASSED ON

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