Mutations are the grist of evolution, and have accumulated in our DNA over time. When populations separate, each group accumulates their own unique set of DNA mutations. Because mutations in a particular sequence of DNA occur at a constant rate, the number of accumulated mutations in that sequence is proportional to the length of time that two groups have been separated. This concept is often known as the "molecular clock."
dna mutations,molecular clock,constant rate,grist,length of time,populations,evolution
- ID: 15980
- Source: DNALC.DNAi
Mutations and the molecular clock.
Geneticist Douglas Wallace explains a method of mapping a population's history using the mutations accumulated by its members.
Evolutionary geneticist Michael Hammer speaks about methods of measuring a population's age by the mutations in its individuals.
Use mutations to measure human evolution.
Human mitochondrial DNA is 16,569 base pairs in length.
Unlike nuclear DNA, mtDNA is Â inherited solely from the mother. (Mitochondria are predominantly from the motherâs egg and not from the fatherâs sperm.) Therefore, mtDNA sequences or orders of nucleotides generally remain constant over many generation
Mutations in our DNA can be used to trace the relationships between different populations and species.
Geneticist Mark Stoneking talks about the difficulties of measuring time by mutations.
Evolutionary geneticist Michael Hammer speaks about the markers used to analyze DNA variation in the Y chromosome.
DNA found in the mitochondrion of a cell differs in structure and is separate from the DNA found in the cell nucleus. Mitochondrial DNA, or mtDNA, exists as a circular loop of double-stranded DNA rather than the linear form found in nuclear DNA. However,