By touching, recently, I know people have more floating ribs than what I learned: A person has ten fixed ribs and two floating ribs.
Who have seen different floating rib numbers?
I can see more floating ribs than 2 and I have two cases whose lower edge rib is on the level of the umbilicus.
If people do develop more floating ribs, what is the evolutionary purpose?
Does it mean the air quality is worse than a decade ago?