BIOL 215 Lecture Notes - Lecture 5: Heterotroph, Parallel Evolution, Polyphyly
Document Summary
The earth was only thousands of years old. There were no extinctions since fossils were representations of species who were still alive. Any adaptation in species was caused by god. When darwin published his book in 1858, these beliefs were altered. The earth was actually more than 300 m. y old. Adaptation is a result of natural selection (not divine intervention) When darwin explored the galapagos islands, he discovered that the species varied from island to island even in such close proximity to each other. Each island had a unique version of nches, and turtles, and other animals. Organisms are always in competition for resources. This was the main idea behind natural selection. Those who survive are said to have more favourable features than competitors, allowing them to pass off these features through genes to their offspring. Breeders select desirable traits and breed through generations until those traits are achieved.