Which chromosome carries a pericentric inversion thought to have contributed to human evolution?

1. Not every structural rearrangement is harmful, and a few have shaped evolution. 2. A pericentric inversion in chromosome 18 appears to have contributed to the evolution of humans. 3. That inversion is not present in chimpanzees, our closest genetic relatives. 4. It is thought to have occurred after the divergence from a common ancestor about five million years ago. 5. Human chromosome two corresponds to two separate chimpanzee chromosomes that are fused, which is a different kind of difference. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 13 "Modern Understandings of Inheritance", section 13.2 Chromosomal Basis of Inherited Disorders_