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

15–1 The Puzzle of Life’s Diversity 1. Patterns of Diversity Section Outline Section 15-1 15–1 The Puzzle of Life’s Diversity A. Voyage of the Beagle B. Darwin’s Observations 1. Patterns of Diversity 2. Living Organisms and Fossils 3. The Galápagos Islands C. The Journey Home

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

evolution theory fossil ________ is a The _______ that Darwin found caused him to ask questions that led to his proposal of the theory of _________. _______ provide evidence to support the theory of fossils ________ is a ______; a testable explanation of naturally-occurring phenomena Evolution theory evolution Fossils evolution theory fossil The _____ record provides for some of the evidence that supports the ______ of evolution fossil theory

Charles Darwin H.M.S. Beagle 5 year The person who contributed the http://harrier.users.netlink.co.uk/Darwin_sm.jpg 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 Image from: Biology by Miller and Levine; Prentice Hall Publishing©2006

Charles Darwin English naturalist (1831) Set sail on the Beagle for a voyage around the world During his travels, Darwin made many observations & collected a great deal of evidence, leading him to propose the theory of evolution

Cont. Charles Darwin Collected fossils preserved remains of ancient organisms Noticed that many plants & animals were very suited to their environments. Spent much time in Galapagos Islands in Pacific Ocean near South America

DARWIN WONDERED? Why do Argentina and Australia have ________ ______ even though they have _____________ _________? Why are there no ______ in Australia and no ________ in England? Why have so many species disappeared? How are these ______ species _______ to living species? different similar grassland animals ecosystems rabbits kangaroos extinct related http://www.rc.umd.edu/praxis/mitchell/images/dinosaur1.gif

Some were hot and dry, with little vegetation. 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 Biology by Miller and Levine; Prentice Hall Publishing©2006 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…

Tortoises from the Galapagos Islands

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. Biology by Miller and Levine; Prentice Hall Publishing©2006 same species different isolated

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

1. Hutton and Geological Change 2. Lyell’s Principles of Geology Section Outline Section 15-2 15–2 Ideas That Shaped Darwin’s Thinking A. An Ancient, Changing Earth 1. Hutton and Geological Change 2. Lyell’s Principles of Geology B. Lamarck’s Evolution Hypotheses 1. Tendency Toward Perfection 2. Use and Disuse 3. Inheritance of Acquired Traits 4. Evaluating Lamarck’s Hypotheses C. Population Growth

Ideas that shaped Darwin’s thinking: In 1785 ______________ proposes that the ______________ by _________________ occurring over __________ periods of time, and is _______________ old. Rocks can be pushed from the ocean floor to form __________. James Hutton Earth was shaped geological forces very long millions of years mountains http://www.creationism.org/books/TaylorInMindsMen/TaylorIMMc03.htm

Ideas that shaped Darwin’s thinking: In 1833 ___________ explains that the geological processes still ___________ have shaped Earth’s features over ________________ Charles Lyell occurring now long periods of time http://www.biologydaily.com/biology/Sir_Charles_Lyell

Ideas that shaped Darwin’s thinking: Theory of Pangaea …and continental drift http://wrgis.wr.usgs.gov/docs/usgsnps/animate/A08.gif

insufficient space & food http://www.nndb.com/people/250/000024178/malthus.jpg 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) http://www.educa.rcanaria.es/fundoro/00.corsi.htm 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 attract mates and ward off predators. Through repeated use, the front claw becomes larger. Lamarck’s Hypothesis: The fiddler passes on this acquired characteristic to its offspring True or false?

What’s wrong with Lamarck’s hypothesis? http://www.geocities.com/arnold_schwarzenegger_pictures/ 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 NO! Acquired traits may help an organism, but they won’t be passed on to offspring.

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 http://pegasus.cc.ucf.edu/~he599900/giraffeeating.jpg

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

Section 15.3 Darwin Presents His Case The beaks of four species of Galapagos finches, from Darwin's Journal of Researches, 1839.

Darwin’s Theory Darwin didn’t publish his ideas for 20 years! Darwin published On the Origins of Species in 1859. It provides evidence that evolution has occurred by NATURAL SELECTION.

Basis of Darwin’s Theory His theory was based on artificial selection:  Animal breeders breed animals only with desired traits. Those desired traits are passed down to the next generation.

Darwin’s Theory: Natural Selection In nature, this is called NATURAL SELECTION.  Individuals best suited to their environment survive & reproduce most successfully.  AKA “Survival Of The Fittest” (sometimes called “Reproduction of the Fittest”)  Struggle For Existence: is there an unlimited food supply?

Darwin’s Theory continued Fitness ability to survive & reproduce in a specific environment Results from adaptations, or inherited characteristics that increase the organism’s chances of survival. Only the fittest organisms pass on their traits to offspring Thus, the species changes over time.

How can you get an adaptation? Can you “get” one at all? Adaptations are inherited characteristics… you are born with them! Adaptations are mutations that are beneficial in a particular environment!

Evidence of Evolution A) Homologous structures structures that have different mature forms but develop from the same embryonic tissues B) Similarities in early development, or embryology C) Fossil record D) Geographical distribution of living organisms (where the organisms are) 32

Homologous Structures 33

Similarities in Embryology In their early stages of development Embryos of different species develop almost identically This provides evidence that they share a common ancestry 34

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