BSC 116 Lecture Notes - Lecture 2: Synapomorphy, Polymerase Chain Reaction, Molecular Clock
23 Jan 2017
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Document Summary
Processes of natural selection and adaptation: members of a population vary in their traits. Differences in genes, proteins, phenotypes, etc: traits are inherited from parents to offspring. Genetic recombination leads to genetic variation: all species are capable of producing more offspring than their environment can support, there is competition for resources, and many of these offspring do not survive to reproduce. May not find a mate, sterility, etc. Microevolution- mutation, selection, and drift can lead to change in populations over time: the ultimate source of phenotypic variation. Genetic variation leads to phenotypic varition: sexual reproduction (recombination) allows alleles to be shared among lineages. Population- group of interbreeding individuals: frequencies of alleles change in populations over time. Selection- increase in the averabe fitness of a population. Important in small populations: as new traits that improve fitness rise through mutation, they eventually replace other traits. Macroevolution- the process of change with time and speciation that resulted in the biodiversity we see today.
