BI110 Lecture Notes - Lecture 1: Genetic Drift, Genetic Code, Cell Membrane
Document Summary
Mutations provide genetic variation among individuals = evolution. Biological evolution: changes in dna sequences (genes and traits they encode) over time. Natural selection: occurs when likelihood of individuals with certain traits surviving and reproducing is higher than those with other traits. Those genes are passed from parent to offspring. Those surviving reproduce and pass that gene on to their offspring. Genetic drift: random processes can determine which individuals survive to reproduce and pass on their dna. Example: a tree in a forest might have fallen due to strong wind; crushing many seedlings below. The dna of the seedlings had nothing to do with them getting crushed, it was random. A seedling could have been lucky and survived the crushing and will be able to grow and reproduce in replacement of the dead tree. Its dna will be passed on in reproduction, whereas the crushed seedlings dna sequence will disappear.
