Six-cluster framework
Regulatory operators
Human-accelerated DNA is not a single kind of change. These six measurements describe how a region was retuned. In the lab they also act as gears: turning them on makes the leftover modes fade faster. The keep-fraction stays 47/125.
01 · ΔE
Enhancer activity
These stretches of DNA do not code for proteins. They act as volume knobs — turning nearby brain-development genes up or down at the right moment.
Raises the drive on developmental target genes.
Example loci
02 · C
Compensatory substitution
When one letter in the sequence changes, another often changes to keep the whole switch working. Evolution rewired the circuit without breaking it.
Preserves function while changing the code.
Example loci
03 · T
Three-dimensional rewiring
The genome folds in 3D. Human-specific changes can re-route which switches sit next to which genes, even if the letters look similar in a straight line.
Changes which genes a switch can reach.
Example loci
04 · D
Copy-number expansion
Sometimes the switch is duplicated. Extra copies give evolution more material to experiment with — one copy keeps the old job, another can specialize.
Adds parallel channels in the regulatory network.
Example loci
05 · L
Deletion and loss
Human evolution also deleted ancestral DNA. Removing an old brake can let a developmental program run longer or start earlier.
Removes ancestral constraints on timing.
Example loci
06 · P
Population spread
Once a change is useful, it spreads. Many HAR variants rose quickly in ancestral humans and are now nearly fixed across living populations.
Locks the human-specific configuration in place.
Example loci