Indeed the only thing about us that remains the same, is the light within, which is our 'spark' from Creator.
Our physical bodies can be anything, any shape. There is so many forms we can be, so many worlds to learn on.
I read in one of my books about past life regression the story a man gave about being in a flood. His only thought was helping the ones he lived with. He tried to help them climb plants and trees to survive. He lost his own life while floating down a 'river' on a leaf.
When asked who and what he was, he answered that he was a worker a part of the whole. Being told to look in the water at his reflection, he saw he was an ant.
Never assume the human race is all there is or the best there is, its just one form we take out of uncountable choices.