Her condition, also called Edwards syndrome, occurs when a person has an extra chromosome 18. Her name, Jacobson said ...

In particular, it explains that humans have one fewer chromosome pair in their cells than apes, due to a mutation found in chromosome number 2 that caused two chromosomes to fuse into one.

Human-accelerated regions (HARs) in chromosomes help human neurons grow multiple neurites. When HARs were added to artificial chimpanzee neurons, as seen on the right, they grew extra neurites, ...