BIOL SCI 150 Chapter Notes - Chapter 16.2: Karyotype, Nuclear Dna, Point Mutation
14 Mar 2018
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Molecular evolution = comparing genome, dna or protein sequences, and chromosome banding patterns in order to see how closely related species are to each other. Similarity of nuclear dna sequences in different species can be used to estimate the time when organisms diverged from a common ancestor. For example, if the rate of base substitution mutation is known, it"s easy to calculate an estimation of how long ago. Humans and chimps differ in 5% of bases, substitutions occur at a rate of 1% per 1 million years, so they probably diverged about 5 million years ago. Using mitochondrial and y chromosome dna sequences. To track ancient human migration patterns, researchers use genetic markers like snps. Markers of mitochondrial dna (mtdna) are used to trace female lineage. Markers of y chromosome sequences are used to trace male lineage. B/c it mutates faster than dna in the nucleus, changing by 2 to.
