Allopatric speciation accurse when a ___ barrier forms preventing population of the same spices from breeding over time new species forms to the barrier.

The pit that marks the location of the umbilical cord after birth is known as the navel or belly button. All animals that grow placenta during fetal development will have a navel or belly button. The scientific name of the structure is the umbillicus. It can be a depression in some individuals or raised in others.