Go to Section: Section Outline 15–1The 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 Section 15-1
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 fossil theory 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 _________. ________ is a ______; a testable explanation of naturally- occurring phenomena The _____ record provides for some of the evidence that supports the ______ of evolution Evolution theory fossils evolution Fossils evolution fossil theory
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? http://www.rc.umd.edu/praxis/mitchell/images/dinosaur1.gif different animals similar grassland ecosystems rabbits kangaroos extinct related
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
Go to Section: Tortoises from the Galapagos Islands
Go to Section: Section Outline 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 Section 15-2
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 __________. very long James Hutton Earth was shaped geological forces millions of years http://www.creationism.org/books/TaylorInMindsMen/TaylorIMMc03.htm mountains
Ideas that shaped Darwin’s thinking: In 1833 ___________ explains that the geological processes still ___________ have shaped Earth’s features over ________________ Charles Lyell occurring now http://www.biologydaily.com/biology/Sir_Charles_Lyell long periods of time
Ideas that shaped Darwin’s thinking: http://wrgis.wr.usgs.gov/docs/usgsnps/animate/A08.gif Theory of Pangaea …and continental drift
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 http://www.nndb.com/people/250/000024178/malthus.jpg
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. changed over time Jean-Baptiste Lamarck (1809) descended Inheritance of Acquired traits http://www.educa.rcanaria.es/fundoro/00.corsi.htm
The male fiddler crab uses its front claw to attract mates and ward off predators. Through repeated use, the front claw becomes larger. The fiddler passes on this acquired characteristic to its offspring Lamarck’s Hypothesis: True or false?
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. http://www.geocities.com/arnold_schwarzenegger_pictures/
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
a.The earth is really old, and slowly changes b.Living things pass changes on to their offspring, leading to species changes c.Sooner or later growing populations run out of resources d.Living things change slowly over time because of competition for resources, and pass those changes on to their offspring Hutton Lyell Malthus Lamarck Match the letter of the idea with the man or men who proposed it:
a.The earth is really old, and slowly changes b.Living things pass changes on to their offspring, leading to species changes c.Sooner or later growing populations run out of resources d.Living things change slowly over time because of competition for resources, and pass those changes on to their offspring Hutton Lyell Malthus Lamarck a. c. b. d.
Go to Section: Concept Map Section 15-3 includes Evidence of Evolution Physical remains of organisms Common ancestral species Similar genes which is composed ofwhich indicateswhich implies The fossil record Geographic distribution of living species Homologous body structures Similarities in early development
Go to Section: Section 15.3 Darwin Presents His Case The beaks of four species of Galapagos finches, from Darwin's Journal of Researches, 1839.
Go to Section: 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.
Go to Section: 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.
Go to Section: 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?
Go to Section: 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.
Go to Section: 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!
Go to Section: 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)
Go to Section: Homologous Structures
Go to Section: 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