Final answer:
The Y chromosome and mtDNA are key tools in tracing human ancestry, with mtDNA passed maternally and the Y chromosome paternally, each illuminating our evolutionary path.
Step-by-step explanation:
The Y chromosomes and mitochondrial DNA (mtDNA) provide different insights into human ancestry due to their distinct patterns of inheritance. Mitochondria, organelles with their own DNA, are passed down maternally and can be used to trace lineage back to Mitochondrial Eve, suggesting our common ancestry. Conversely, the Y chromosome is inherited paternally, allowing for the paternal lineage to be followed. Both have been instrumental in charting human evolutionary history, with mitochondrial DNA suggesting a common maternal ancestor around 160,000 years ago and Y chromosome analyses indicating a common paternal ancestor about 140,000 years ago.
MtDNA mutations serve as molecular clocks to estimate genetic divergence timelines. Unlike nuclear DNA, which recombines and mutates at a slower rate, the rate of mutation in mtDNA is higher, making it a valuable tool for understanding the more recent aspects of human evolution. These different molecular tools provided by mtDNA and the Y chromosome are central to the field of molecular anthropology.