Which came first? Mouth or Anus? 😅

It ain’t a joke!

Baby development from embryo

Humans are complex animals and complex animals are classified based on their embryo development. There are two kinds of classifications: Protostome and Deuterostome. During embryo development the first opening is called the blastopore. What this blastopore becomes into decides whether the animal is a protostome or deuterostome.