Which came first? Mouth or Anus? 😅
It ain’t a joke!
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.
In deuterostome, the developing embryo’s first opening (the blastopore) becomes the anus and the gut tunnels into embryo later on and forms the mouth. In Protostome, the developing embryo’s first opening (the blastopore) becomes the mouth and the gut tunnels into embryo later on and forms the anus. Two different openings, one for food and another for feces and the gut in-between ensures that for both deuterostomes and protostomes the food is properly digested and nutrients are well absorbed.
Examples of deuterostomes and protostomes
All mammals, reptiles, amphibians are deuterostomes whereas all insects are protostomes.
Are humans protostome or deuterostome?
Since humans are mammals, they are deuterostomes.
Which came first? Mouth or Anus?
Humans are deuterostomes. This means that for humans, the anus forms first and later the mouth.
Deuterostome is a Greek word, Deutero means “second” and Stoma means “opening” or “mouth”. Thus Deuterostome translates to “second mouth”.