Presentation on theme: "Evidence of Evolution 15.1. Blindfold Demo I. Evolution Definitions A. Evolution- Change in inherited traits of a POPULATION (not individuals) over time."— Presentation transcript:
I. Evolution Definitions A. Evolution- Change in inherited traits of a POPULATION (not individuals) over time. B. Variation- Changes between members of the same species caused by DNA mutations.
II. Charles Darwin A. It all began on the English ship, the HMS Beagle 1. Darwin worked as the naturalists 2. He took samples of living specimens and fossils
II. Charles Darwin B. Darwin’s observations in the Galapagos Islands 1. Species are unique, yet similar to species elsewhere 2. Species produce many offspring, but don’t overrun the earth
II. Charles Darwin 3. Individuals in a species struggle to survive a. Compete for food b. Compete for shelter c. Compete for water d. Etc
II. Charles Darwin C. Pigeon experiments 1. Darwin realizes that he can select and breed specific pigeons to get a desired trait.
II. Charles Darwin 2. Artificial Selection- Breeding organisms with specific traits in order to produce offspring with identical traits. a. Similar to a force in nature that causes changes
II. Charles Darwin D. Natural Selection- Organisms with favorable traits for their environment survive and reproduce. Organisms without favorable traits die! 1. Survival of the fittest!!! 2. Causes changes in populations a. Car demo
II. Charles Darwin E. Principles of Natural Selection 1. Organisms produce more offspring than can survive 2. Differences, AKA variations occur among individual species 3. Some variations are passed to the offspring
II. Charles Darwin 4. Some variations are helpful and help organisms to survive and reproduce better. 5. Over time, individuals with the helpful variations make up more of the population and often becomes a separate species.
III. Evidence for Evolution A. Adaptations that increase survival 1. Structural 1. Structural a. Body parts Body partsBody parts b. Camouflage c. Mimicry
III. Evidence for Evolution 2. Physiological- Changes in metabolism a. Penicillin resistant bacteria b. Pesticide resistant insects
III. EVIDENCE FOR EVOLUTION B. Fossils & Transition Fossils 1. Archeopteryx: intermediate between reptiles & birds 2. Eustheopteron: fish to amphibians 3. Seymouria: amphibian to reptiles 4. Therapsids: reptiles to mammals
III. EVIDENCE FOR EVOLUTION C. Anatomical Evidence 1. Homologous Structures- Structure with similar origins (shape, function, etc) a. Provides evidence of common ancestor b. Ex: Forelimbs of whales, crocodiles and birds