Every time we learn more about genes and their operations we add complexity. Epigenetics has added a dimension which oftentimes surpasses much of what we have learned before. In a recent Science article the authors examine the epigenetic differences in humans and their ancestors. They state:
Ancient DNA sequencing has recently provided high-coverage archaic human
genomes. However, the evolution of epigenetic regulation
along the human lineage remains largely
unexplored. We reconstructed the full DNA methylation maps of the
Neandertal and the
Denisovan by harnessing the natural degradation
processes of methylated and unmethylated cytosines. Comparing these
ancient
methylation maps to those of present-day humans,
we identified ~2000 differentially methylated regions (DMRs).
Particularly,
we found substantial methylation changes in the
HOXD cluster that may explain anatomical differences between archaic and
present-day
humans. Additionally, we found that DMRs are
significantly more likely to be associated with diseases. This study
provides
insight into the epigenetic landscape of our
closest evolutionary relatives and opens a window to explore the
epigenomes of
extinct species.
This is an interesting first step well worth the following!
One suspects that the more we understand methylation, miRNAs etc the better we can understand some of the vagaries of life.