chr2 · 2q14 · 268 nt · 2006

HAR7

What it is

HAR7's substitutions tend to cancel each other's damage and come with a 3D contact shift. That is the signature of a circuit being retuned, not a circuit being broken.

Why it matters

Compensatory + topology signature.

Operator load

• 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.

• 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.

• 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.

Pollard et al. 2006