Human babies born on Mars will not be human

Of course they will still be human.

If the parents are human then they are, by definition, human. Doesn't matter if you are conceived on Mars on in Minnesota you will still be human.

There are certain groups of people on Earth who have slightly different characteristic to the majority due to local variations. For example, the people who live high up in the mountains of places like Tibet have a make up that allows them to function properly when in an oxygen depleted atmosphere.

HAL.