Topic: Name: ____________________________ Date:_________________________ Natural Selection Objective: SWBAT understand the how species change over time. Questions/Main Ideas: Who is Charles Charles Darwin- first to propose the theory of evolution (how species change Darwin? over time). - Joined the crew on the H.M.S. Beagle as a naturalist from England to journey around the world - Through his observations, including those made in the Galapagos Islands, Charles Darwin formulated a theory of how species change over time, called Natural Selection. - In 1859, Darwin published his ideas in the book, The Origin of Species How did studying Galapagos Islands- chain of islands off the coast of South America organisms on the - Each island is very different and isolated from outside predators Galapagos Islands lead - There’s competition among the organisms to survive to the Theory of - Even in the most inhabitable parts, there were some organisms able to Evolution? survive - What factors determined which organisms survived? What is Natural Theory of Natural Selection= A process by which organisms with traits well Selection? suited to an environment survive and reproduce at a greater rate than organisms less suited to that environment, and is governed by the principles of genetics. - The survival rate of offspring- children must survive to pass on traits - The struggle for existence- competition for limited resources, such as: water, food, shelter, etc - Variety within a population- differences between species may make some better adapted for their environment, able to survive, reproduce, and pass those traits onto their offspring. - Populations change over time- a species’ ability to adapt will help it survive - Descent with modification- Organisms today have descended and modified themselves from organisms of the past. All organisms have a common ancestor/ descendent. Ex) Giraffes What is Survival of the Fittest? Survival of the Fittest= organisms best favored in certain environments will live and reproduce Adaptation= a trait that allows an organism to be better fit to survive in a certain environment Ex) White fur on a polar bear Jean Baptiste Lamarck Who is Jean Baptiste - zoologist credited with the idea of the inheritance of acquired traits Lamarck? - He thought that if a trait changed over an organism’s lifetime that it could pass it onto its offspring - Example- a bodybuilder lifts weights to build stronger muscle and then has a really strong baby- NOT TRUE! What are some Tools for Survival adaptations for - Mimicry= Copying another organism in order to survive survival? o Ex) the king snake is brightly colored like the coral snake, but only the coral snake is poisonous - Trickery= Using color patterns to confuse predators o Ex) The butterfly fish has a false eyespot on its fin so predators can never tell which way the fish is facing - Camouflage= Being able to blend into the surroundings o Ex) snow fox or the peppered moth - Tolerance= Building up resistance to something over time o Ex) Antibiotic resistant bacteria due to over exposure Why do we study Fossils= any evidence of an organism that lived long ago. fossils? - Scientists, including Darwin, collect fossils to see how species have changed over time. - Scientists determine the relative age of a fossil by looking at the position in the rock and absolute dating by radioactive decay. - Relative dating= Putting fossils in chronological order of age because there is no actual numerical data - Absolute dating= Assign an actual age to fossils based on the half-life decay of chemicals Ex) Carbon 14 dating How do we compare Comparing structures structures between - Homologous structures- similar physical structure, but with different uses organisms? o Example= Bat wings, whale flippers, human hand, and dog’s paw - Analogous structures- similar function, but different in physical structure o Example= Butterfly and bat wings What are vestigial Vestigial organs= organs that remain but no longer have a function organs? - may be reduced in size - Ex) appendix, eyes of cave dwelling organisms, pelvic bones of whales and dolphins Why do we study Embryology= study of how embryology? organisms develop. - Focuses on the similarities during development even though the adults look different Summary: .