Darwin's Theory of Natural Selection

SUMMARY: 1) 5 year voyage, 19th Century, Studied variation of: plants, animals & fossils, on 4 continents on the HMS Beagle 2) observed many organisms including finches, tortoises and mocking bird (during his 5 week visit to the Galapagos Islands). 3) Published his scientific work 28 yrs after his voyage in the book On the Origin of Species, which was published in 1859. His observations were backed by many years of experimentation PROPOSED THAT: 1) individual organisms within a particular species show a wide range of variation for a characteristic 2) individuals with characteristics most suited to the environment are more likely to survive to breed successfully 3) the characteristics that have enabled these individuals to survive are then passed on to the next generation 4) Eg, finches: diff beak/claw sizes depending on the local food source, because the islands were far from the mainland, the finches that had arrived changed over time ISSSUES: 1) the theory challenged the idea that God made all animals and plants that live on Earth (creationism) 2) there was insufficient evidence when the theory was published to convince many scientists 3) the mechanism of inheritance and variation was not known until 50 years after the theory was published